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Chip Jones
August 19th 03, 01:36 AM
The other day, I had an air traffic situation I wanted to bounce off of the
group. Those of you who don't know me, I'm a Center controller down here in
Atlanta. Here's the deal.

I was working a Center departure sector mixing Atlanta terminal departures
of every ilk and kin with enroute overflight traffic north of metro Atlanta.
The sector weather was typical summer MVFR down here- lots of convection,
hazy, hot, humid etc with building thunderstorms here and there impacting
the sector. I had received my briefing from the previous controller and had
just assumed responsibility for the airspace. Part of my technique is to do
one more quick traffic scan *after* I take over (while the previous
controller is still at hand) to ensure we didn't fumble a situation while we
changed the guard.

I am working a Baron IFR at 7000 flying from Chattanooga TN to Charleston
SC, on course heading of about 110 or so. Doing my scan, I see he has an
IFR off the nose about 15 miles at 6000 and another IFR guy crossing from
the NE at 8000 and 20 miles, so he is separated. I notice additional
traffic for this guy, a VFR indicating 6600 about six miles south, heading
about 055 or so, converging with him. I ask the previous controller if
she had issued traffic, she said she hadn't.

I made the traffic call.. "Baron 123, VFR traffic one to two o'clock, six
miles, northeast bound converging, altitude indicates six thousand six
hundred." The response I get is "Baron 123 is IMC, no contact."

I make a few unrelated routine calls to other traffic, keeping an eye on
this VFR target. His Mode C indicates that he is in a climb, and the
conflict alert activates (both data blocks begin to flash). I make another
call at four miles. "Baron 123, your traffic now two o'clock, four miles,
northeast bound, altitude indicating six thousand niner hundred VFR,
converging right to left." The Baron responds "123 is IMC, no contact."
The situation now has my undivided attention.

At three miles converging (next update), the traffic is indicating 7000.
The next update, the traffic is still at 7000. This guy is flying VFR where
one of my IFR's is IMC. I swing into alert mode. The target slashes are a
mile long each and the radar display is delayed a bit from actual position
so these guys are getting close and closing fast. The Baron needs to yank
it right most ricky tic and get behind this guy.

In the most professionally bored voice I can muster, I key up and say "Baron
123, traffic alert, traffic two o'clock, two miles converging from the right
indicating 7000, suggest you turn right heading 180 immediately." The Baron
pilot says "We're turning left to 090, no contact." I then watch as the
Baron swings into a left turn, prolonging the collision vector another
minute. His left turn away from the traffic puts him wing high with closing
traffic off the right side. The Baron also descends four hundred feet
during the maneuver as the targets merge. To me, this looks remarkably like
a TCAS maneuver because of the altitude change. I key up and say "N123, are
you TCAD equipped, do you have traffic avoidance avionics?" He gives me a
curt "Negative, we do not have the traffic." The targets have merged thanks
to the left turn, and I cannot distinguish the one from the other. Anything
I say now about the traffic would be a dangerous guess because I have lost
the flick between these two aircraft. Instead of responding to the Baron, I
issue a vector to the IFR traffic at 6000 to get him away from Baron 123
(who is now well below assigned IFR altitude). At the next position update,
I have tail to tail between the baron and the VFR. I tell the Baron,
"Traffic no factor, maintain 7000." He responds "We never saw him..." [The
unknown SOB in the VFR remains at 7000 for the next fifty miles- his profile
never changed and I have every reason to believe that he never saw the IFR,
IMC Baron].

My question for the group is about the Baron pilot's decision to disregard
my suggestion to yank it towards the traffic and instead to turn away from
him. From a controller's perspective, the quickest way to achieve "Oh Sh*t"
lateral separation with crossing traffic is to aim one airplane right at the
other. The idea is that as both aircraft are moving through space, the
maneuvering aircraft is steering for a point where the traffic *used* to be
but no longer is. Once the nose of the turning aircraft swings through his
traffic's vector, every additional second buys additional separation. When
we do this with IFR traffic, we call this a "Wimpy Crossover" or a "Bubba
Turn". If an aircraft turns away from conflicting crossing traffic, every
additional second of turn sees the targets get closer until either they
merge or else they *finally* get to the point of course divergence. The
closer the targets are when an away turn is initiated, the less effective an
"away" turn is.

Given this traffic scenario, would any of you guys have followed my
suggestion to turn to a 180 heading, or was I wasting my breath?

Chip, ZTL








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Bob Gardner
August 19th 03, 01:58 AM
This was drilled into us for shiphandling at sea...turn into the conflicting
traffic. Sad thing is that if you had yelled at the Baron "Negative, turn
right immediately," the situation would have gotten worse, not better.

I hope you tracked the intruder to his destination.

Bob Gardner

"Chip Jones" > wrote in message
...
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in
> Atlanta. Here's the deal.
>
> I was working a Center departure sector mixing Atlanta terminal departures
> of every ilk and kin with enroute overflight traffic north of metro
Atlanta.
> The sector weather was typical summer MVFR down here- lots of convection,
> hazy, hot, humid etc with building thunderstorms here and there impacting
> the sector. I had received my briefing from the previous controller and
had
> just assumed responsibility for the airspace. Part of my technique is to
do
> one more quick traffic scan *after* I take over (while the previous
> controller is still at hand) to ensure we didn't fumble a situation while
we
> changed the guard.
>
> I am working a Baron IFR at 7000 flying from Chattanooga TN to Charleston
> SC, on course heading of about 110 or so. Doing my scan, I see he has an
> IFR off the nose about 15 miles at 6000 and another IFR guy crossing from
> the NE at 8000 and 20 miles, so he is separated. I notice additional
> traffic for this guy, a VFR indicating 6600 about six miles south, heading
> about 055 or so, converging with him. I ask the previous controller if
> she had issued traffic, she said she hadn't.
>
> I made the traffic call.. "Baron 123, VFR traffic one to two o'clock, six
> miles, northeast bound converging, altitude indicates six thousand six
> hundred." The response I get is "Baron 123 is IMC, no contact."
>
> I make a few unrelated routine calls to other traffic, keeping an eye on
> this VFR target. His Mode C indicates that he is in a climb, and the
> conflict alert activates (both data blocks begin to flash). I make
another
> call at four miles. "Baron 123, your traffic now two o'clock, four miles,
> northeast bound, altitude indicating six thousand niner hundred VFR,
> converging right to left." The Baron responds "123 is IMC, no contact."
> The situation now has my undivided attention.
>
> At three miles converging (next update), the traffic is indicating 7000.
> The next update, the traffic is still at 7000. This guy is flying VFR
where
> one of my IFR's is IMC. I swing into alert mode. The target slashes are
a
> mile long each and the radar display is delayed a bit from actual position
> so these guys are getting close and closing fast. The Baron needs to yank
> it right most ricky tic and get behind this guy.
>
> In the most professionally bored voice I can muster, I key up and say
"Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the
right
> indicating 7000, suggest you turn right heading 180 immediately." The
Baron
> pilot says "We're turning left to 090, no contact." I then watch as the
> Baron swings into a left turn, prolonging the collision vector another
> minute. His left turn away from the traffic puts him wing high with
closing
> traffic off the right side. The Baron also descends four hundred feet
> during the maneuver as the targets merge. To me, this looks remarkably
like
> a TCAS maneuver because of the altitude change. I key up and say "N123,
are
> you TCAD equipped, do you have traffic avoidance avionics?" He gives me a
> curt "Negative, we do not have the traffic." The targets have merged
thanks
> to the left turn, and I cannot distinguish the one from the other.
Anything
> I say now about the traffic would be a dangerous guess because I have lost
> the flick between these two aircraft. Instead of responding to the Baron,
I
> issue a vector to the IFR traffic at 6000 to get him away from Baron 123
> (who is now well below assigned IFR altitude). At the next position
update,
> I have tail to tail between the baron and the VFR. I tell the Baron,
> "Traffic no factor, maintain 7000." He responds "We never saw him..."
[The
> unknown SOB in the VFR remains at 7000 for the next fifty miles- his
profile
> never changed and I have every reason to believe that he never saw the
IFR,
> IMC Baron].
>
> My question for the group is about the Baron pilot's decision to disregard
> my suggestion to yank it towards the traffic and instead to turn away from
> him. From a controller's perspective, the quickest way to achieve "Oh
Sh*t"
> lateral separation with crossing traffic is to aim one airplane right at
the
> other. The idea is that as both aircraft are moving through space, the
> maneuvering aircraft is steering for a point where the traffic *used* to
be
> but no longer is. Once the nose of the turning aircraft swings through
his
> traffic's vector, every additional second buys additional separation.
When
> we do this with IFR traffic, we call this a "Wimpy Crossover" or a "Bubba
> Turn". If an aircraft turns away from conflicting crossing traffic, every
> additional second of turn sees the targets get closer until either they
> merge or else they *finally* get to the point of course divergence. The
> closer the targets are when an away turn is initiated, the less effective
an
> "away" turn is.
>
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?
>
> Chip, ZTL
>
>
>
>
>
>
>
>
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Henry Bibb
August 19th 03, 02:13 AM
I'd have *asked* for the vector by about the second call, if I couldn't see
him.
I do that even in VFR with flight following.

Henry Bibb

"Chip Jones" > wrote in message
...
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in
> Atlanta. Here's the deal.
>
> interesting story snipped.

Stan Gosnell
August 19th 03, 02:14 AM
"Chip Jones" > wrote in
:

<long story snipped...>

> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?

I think I would have turned in the direction you gave, since I couldn't see
the traffic & presumably you could, at least on radar. You have a much
bigger picture than I do. Either he misunderstood you or he's a lot more
arrogant than I like to think I am. If he knows he's faster than the
converging traffic, a turn away could work, but how could he know that?
OTOH, if you really, really want him to turn to a heading, give it as an
instruction, not a suggestion.

Turning the wrong way & losing that much altitude in the turn suggests a
lack of proficiency, but who knows?

--
Regards,

Stan

Jim Vadek
August 19th 03, 02:23 AM
If the Baron pilot ever gets a chance to read this, I suspect he might
follow ATC suggestions in the future. As for your question: I cannot think
of a time that I have not followed ATC suggestions for traffic avoidance.

Perhaps the Baron did seen the traffic.

"Chip Jones" > wrote in message
...
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in
> Atlanta. Here's the deal.
>
> I was working a Center departure sector mixing Atlanta terminal departures
> of every ilk and kin with enroute overflight traffic north of metro
Atlanta.
> The sector weather was typical summer MVFR down here- lots of convection,
> hazy, hot, humid etc with building thunderstorms here and there impacting
> the sector. I had received my briefing from the previous controller and
had
> just assumed responsibility for the airspace. Part of my technique is to
do
> one more quick traffic scan *after* I take over (while the previous
> controller is still at hand) to ensure we didn't fumble a situation while
we
> changed the guard.
>
> I am working a Baron IFR at 7000 flying from Chattanooga TN to Charleston
> SC, on course heading of about 110 or so. Doing my scan, I see he has an
> IFR off the nose about 15 miles at 6000 and another IFR guy crossing from
> the NE at 8000 and 20 miles, so he is separated. I notice additional
> traffic for this guy, a VFR indicating 6600 about six miles south, heading
> about 055 or so, converging with him. I ask the previous controller if
> she had issued traffic, she said she hadn't.
>
> I made the traffic call.. "Baron 123, VFR traffic one to two o'clock, six
> miles, northeast bound converging, altitude indicates six thousand six
> hundred." The response I get is "Baron 123 is IMC, no contact."
>
> I make a few unrelated routine calls to other traffic, keeping an eye on
> this VFR target. His Mode C indicates that he is in a climb, and the
> conflict alert activates (both data blocks begin to flash). I make
another
> call at four miles. "Baron 123, your traffic now two o'clock, four miles,
> northeast bound, altitude indicating six thousand niner hundred VFR,
> converging right to left." The Baron responds "123 is IMC, no contact."
> The situation now has my undivided attention.
>
> At three miles converging (next update), the traffic is indicating 7000.
> The next update, the traffic is still at 7000. This guy is flying VFR
where
> one of my IFR's is IMC. I swing into alert mode. The target slashes are
a
> mile long each and the radar display is delayed a bit from actual position
> so these guys are getting close and closing fast. The Baron needs to yank
> it right most ricky tic and get behind this guy.
>
> In the most professionally bored voice I can muster, I key up and say
"Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the
right
> indicating 7000, suggest you turn right heading 180 immediately." The
Baron
> pilot says "We're turning left to 090, no contact." I then watch as the
> Baron swings into a left turn, prolonging the collision vector another
> minute. His left turn away from the traffic puts him wing high with
closing
> traffic off the right side. The Baron also descends four hundred feet
> during the maneuver as the targets merge. To me, this looks remarkably
like
> a TCAS maneuver because of the altitude change. I key up and say "N123,
are
> you TCAD equipped, do you have traffic avoidance avionics?" He gives me a
> curt "Negative, we do not have the traffic." The targets have merged
thanks
> to the left turn, and I cannot distinguish the one from the other.
Anything
> I say now about the traffic would be a dangerous guess because I have lost
> the flick between these two aircraft. Instead of responding to the Baron,
I
> issue a vector to the IFR traffic at 6000 to get him away from Baron 123
> (who is now well below assigned IFR altitude). At the next position
update,
> I have tail to tail between the baron and the VFR. I tell the Baron,
> "Traffic no factor, maintain 7000." He responds "We never saw him..."
[The
> unknown SOB in the VFR remains at 7000 for the next fifty miles- his
profile
> never changed and I have every reason to believe that he never saw the
IFR,
> IMC Baron].
>
> My question for the group is about the Baron pilot's decision to disregard
> my suggestion to yank it towards the traffic and instead to turn away from
> him. From a controller's perspective, the quickest way to achieve "Oh
Sh*t"
> lateral separation with crossing traffic is to aim one airplane right at
the
> other. The idea is that as both aircraft are moving through space, the
> maneuvering aircraft is steering for a point where the traffic *used* to
be
> but no longer is. Once the nose of the turning aircraft swings through
his
> traffic's vector, every additional second buys additional separation.
When
> we do this with IFR traffic, we call this a "Wimpy Crossover" or a "Bubba
> Turn". If an aircraft turns away from conflicting crossing traffic, every
> additional second of turn sees the targets get closer until either they
> merge or else they *finally* get to the point of course divergence. The
> closer the targets are when an away turn is initiated, the less effective
an
> "away" turn is.
>
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?
>
> Chip, ZTL

Ray Andraka
August 19th 03, 02:29 AM
Either that or he wasn't really IMC, but didn't want to fess up (in which case
he probably stained his undies too). What the motivation for that would be, I
wouldn't know.

Stan Gosnell wrote:

> Turning the wrong way & losing that much altitude in the turn suggests a
> lack of proficiency, but who knows?
>
> --
> Regards,
>
> Stan

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

Roy Smith
August 19th 03, 02:55 AM
"Chip Jones" > wrote:
> Here's the deal.

An interesting choice of words :-)

> In the most professionally bored voice I can muster, I key up and say "Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the right
> indicating 7000, suggest you turn right heading 180 immediately."
> [...]
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?

Hard to say for sure, but I can offer a few insights from my own
experiences. As a general rule, if the controller says, "immediately",
I put my life in his hands, follow orders, and ask questions later.

I've only once heard the phrase "traffic alert". I was IFR, the
controller was not talking to the other guy. It was not solid IMC, but
there was plenty of IMC around. I can only guess the other guy was not
legal VFR.

In this case, the controller did not issue a suggested heading. My
response was to turn 90 degrees away from the direction the traffic was
being called. I can certainly see your point where turning directly
into the traffic would have put me behind him, but that wasn't my
instinctive reaction.

I suspect your traffic call may have been by the book, but on the other
hand, it was probably too verbose to really be useful to the pilot. I'm
guessing that with each successive traffic call leading up to the alert,
the pilot was getting increasingly antsy about the unseen traffic, and
already working out an escape plan -- "bad stuff to the right, I gotta
get left, away from the danger". All it took was hearing the words
"traffic alert" to trigger that plan into action.

I just timed how long it took me to calmly read the above clearance.
Seven seconds between "traffic alert" and "heading 180". At standard
rate, the guy's already 20 degrees into his left turn before he knows
you want him to turn right (and I'm not sure I would limit myself to
standard rate in response to a traffic alert). More than the physics of
changing heading, consider the human factors -- he's already made a
decision and acted on it. He's already made the mental leap from
obeying instructions to acting on his own. It's not going to be easy to
get him back into the fold quickly.

My guess is, by-the-book or not, a better way to say it might have been,
"Barron 123, traffic alert, immediate left turn, heading 180". Get it
right up front what you want the guy to do.

I fully understand the reason the book wants the phrasing the way it
does. It's the PIC's decision, and the controller is just feeding the
PIC information which will let the PIC make an informed decision. The
problem is, I don't think it works that way in real life. It's hard
enough working CPA problems (Closest Point of Approach; do they call it
that in the ATC world?) looking at a screen or a plotting sheet. It's
damn near impossible in your head with nothing better than an O'Clock
traffic call, some dubious WCA, an unknown speed and cardinal heading on
the target, and no formal training.

PIC-correctness, legality, and liability issues aside, the fact is the
controller is the one with the best picture of what's going on, and it
makes the most sense for the controller to take charge and issue an
unambigious instruction, with no extraneous information to get in the
way of communicating the one thing you really want to communicate: which
way to turn.

It's a pity there's no mechanism to plan stuff like this a little
further in advance. At the 5-mile point, it would be nice if I could
hear, "Hold current heading for now. If you don't see him in another 3
miles, I'm going to turn you left to pass behind him". Does "the book"
allow for such a conversation?

My other hobby is racing sailboats. A very important part of the sport
is judging crossing situations. I'm here, you're there. I'm on this
heading and speed, you're on that heading and speed. Will I cross in
front of you? Will you cross in front of me? There's often a big
tactical advantage to me crossing in front (as opposed to changing
heading to make sure I cross behind), so there's a lot of incentive to
learn how to judge these things closely.

You don't want a surprise. If we're not sure of the crossing situation,
we want to have a plan as far in the future as we can as to what we'll
do if it gets to the decision point and it's still not clear we can make
it across the other guy's bow. That way, when the time comes, I don't
have to explain what Plan-B is, we just have to tell the crew that
Plan-B is what we're doing.

Think about what was going on from the pilot's perspective. You kept
telling him, "Something bad might be happening soon. I know the best
way to deal with it, but I won't tell you what it is yet. Don't worry,
though, at the last possible second I'll clue you in on the plan and
then expect you to react immediately".

Well, anyway, that's my take on it. Other people will probably have
different opinions.

Chip Jones
August 19th 03, 02:58 AM
"Gary L. Drescher" > wrote in message
news:3te0b.185696$uu5.34850@sccrnsc04...
> "Chip Jones" > wrote in message
> ...
> > Given this traffic scenario, would any of you guys have followed my
> > suggestion to turn to a 180 heading, or was I wasting my breath?
>
> At my level of (in)experience, I'll follow any ATC suggestion unless I
have
> specific reason to do otherwise--especially in a traffic-alert situation
in
> IMC. I do try to assess for myself the reasonableness of any ATC
> suggestion, instruction, or clearance, and I'll balk if I have reason to.
> But unless I see a specific problem with your suggestion, I'm going to
> comply. (I suppose I might have thought it strange to be turned *into*
the
> traffic, and might have asked you to "confrim right turn".)
>
> The idea of rogue IMC aircraft is pretty scary. Was there any way to
track
> that plane until it landed somewhere?
>

Well, I could have tracked him if I had wanted to, but there is no real way
of *proving* that he was breaking any rules.

Chip, ZTL




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John Gaquin
August 19th 03, 03:05 AM
"Chip Jones" > wrote in message
>
> My question for the group is.....

I was taught long ago that when a controller uses the word "immediate",
compliance should be thus. I still believe that to be good policy. Too bad
you couldn't nick the guy for disregarding.

Regards,

John Gaquin
B727, B747

Matthew Chidester
August 19th 03, 03:13 AM
i'd make both file a report with the ATC manager - I think FAR's say
something about how even though a rule had not been broken (or maybe it had)
if you have both N#'s you can just request them to file a report (or next
time)

Matthew


"John Gaquin" > wrote in message
...
>
> "Chip Jones" > wrote in message
> >
> > My question for the group is.....
>
> I was taught long ago that when a controller uses the word "immediate",
> compliance should be thus. I still believe that to be good policy. Too
bad
> you couldn't nick the guy for disregarding.
>
> Regards,
>
> John Gaquin
> B727, B747
>
>

Ben Jackson
August 19th 03, 03:21 AM
In article >,
Chip Jones > wrote:
>
>In the most professionally bored voice I can muster, I key up and say "Baron
>123, traffic alert, traffic two o'clock, two miles converging from the right
>indicating 7000, suggest you turn right heading 180 immediately."

Why did it get that far? If I'm the Baron I'm thinking, "I can't see
the traffic, I won't see the traffic in IMC, why is this guy waiting
for me to spot this plane?" If you *believed* that he was really in
the soup, why not just pretend the VFR target was a lost-comms IFR
guy and gotten the Baron out of the way?

Plus if two aircraft are 2 miles apart and you turn one 90 degrees,
by the time the turn is completed they will have both covered a mile.
My mental image of this is that you're turning a situation where the
two course lines would converge to a sharp point into a situation
where they would converge in a nice rounded corner.

--
Ben Jackson
>
http://www.ben.com/

Robert Henry
August 19th 03, 03:23 AM
"Chip Jones" > wrote in message
...
>
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?
>
> Chip, ZTL

It reminds me of the scene in the Hunt for Red October where Jack Ryan has
to choose between steering the sub into the torpedo or away from the
torpedo. As such, I think the pilot feared a head on; a 70 degree turn is
about a mile in a cruising Baron. The Baron also guessed that he could
descend away from the climbing aircraft as reported - guessing (correctly
fortunately) that the interloper would not descend back out of the weather.
(a 400 ft altitude change following a 6 second turn should be considered
deliberate, imho.)

Based solely upon the vectors you listed, I also think the course he chose
(~20 left) put the aircraft closer to the destination instead of further
away, which may have also been a factor in his decision-making process.

Maybe a left 360 would have done the trick more comfortably for everyone? I
was recently "spun" in VMC about 3 miles from a VOR at 7000 in an SR22 with
no traffic reported -although I presumed that was the problem- which is what
made me think of it. It's puts the plane right back where it started, just
two minutes later.

While we hope never to be faced with an unverified target in IMC, please
make the suggestion that best resolves the conflict from your viewpoint.


--

Bob
PP-ASEL-IA, A/IGI

Steven P. McNicoll
August 19th 03, 03:34 AM
"Chip Jones" > wrote in message
...
>
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in
> Atlanta. Here's the deal.
>
> I was working a Center departure sector mixing Atlanta terminal departures
> of every ilk and kin with enroute overflight traffic north of metro
Atlanta.
> The sector weather was typical summer MVFR down here- lots of convection,
> hazy, hot, humid etc with building thunderstorms here and there impacting
> the sector. I had received my briefing from the previous controller and
had
> just assumed responsibility for the airspace. Part of my technique is to
do
> one more quick traffic scan *after* I take over (while the previous
> controller is still at hand) to ensure we didn't fumble a situation while
we
> changed the guard.
>
> I am working a Baron IFR at 7000 flying from Chattanooga TN to Charleston
> SC, on course heading of about 110 or so. Doing my scan, I see he has an
> IFR off the nose about 15 miles at 6000 and another IFR guy crossing from
> the NE at 8000 and 20 miles, so he is separated. I notice additional
> traffic for this guy, a VFR indicating 6600 about six miles south, heading
> about 055 or so, converging with him. I ask the previous controller if
> she had issued traffic, she said she hadn't.
>
> I made the traffic call.. "Baron 123, VFR traffic one to two o'clock, six
> miles, northeast bound converging, altitude indicates six thousand six
> hundred." The response I get is "Baron 123 is IMC, no contact."
>
> I make a few unrelated routine calls to other traffic, keeping an eye on
> this VFR target. His Mode C indicates that he is in a climb, and the
> conflict alert activates (both data blocks begin to flash). I make
another
> call at four miles. "Baron 123, your traffic now two o'clock, four miles,
> northeast bound, altitude indicating six thousand niner hundred VFR,
> converging right to left." The Baron responds "123 is IMC, no contact."
> The situation now has my undivided attention.
>
> At three miles converging (next update), the traffic is indicating 7000.
> The next update, the traffic is still at 7000. This guy is flying VFR
where
> one of my IFR's is IMC. I swing into alert mode. The target slashes are
a
> mile long each and the radar display is delayed a bit from actual position
> so these guys are getting close and closing fast. The Baron needs to yank
> it right most ricky tic and get behind this guy.
>
> In the most professionally bored voice I can muster, I key up and say
"Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the
right
> indicating 7000, suggest you turn right heading 180 immediately." The
Baron
> pilot says "We're turning left to 090, no contact." I then watch as the
> Baron swings into a left turn, prolonging the collision vector another
> minute. His left turn away from the traffic puts him wing high with
closing
> traffic off the right side. The Baron also descends four hundred feet
> during the maneuver as the targets merge. To me, this looks remarkably
like
> a TCAS maneuver because of the altitude change. I key up and say "N123,
are
> you TCAD equipped, do you have traffic avoidance avionics?" He gives me a
> curt "Negative, we do not have the traffic." The targets have merged
thanks
> to the left turn, and I cannot distinguish the one from the other.
Anything
> I say now about the traffic would be a dangerous guess because I have lost
> the flick between these two aircraft. Instead of responding to the Baron,
I
> issue a vector to the IFR traffic at 6000 to get him away from Baron 123
> (who is now well below assigned IFR altitude). At the next position
update,
> I have tail to tail between the baron and the VFR. I tell the Baron,
> "Traffic no factor, maintain 7000." He responds "We never saw him..."
[The
> unknown SOB in the VFR remains at 7000 for the next fifty miles- his
profile
> never changed and I have every reason to believe that he never saw the
IFR,
> IMC Baron].
>
> My question for the group is about the Baron pilot's decision to disregard
> my suggestion to yank it towards the traffic and instead to turn away from
> him. From a controller's perspective, the quickest way to achieve "Oh
Sh*t"
> lateral separation with crossing traffic is to aim one airplane right at
the
> other. The idea is that as both aircraft are moving through space, the
> maneuvering aircraft is steering for a point where the traffic *used* to
be
> but no longer is. Once the nose of the turning aircraft swings through
his
> traffic's vector, every additional second buys additional separation.
When
> we do this with IFR traffic, we call this a "Wimpy Crossover" or a "Bubba
> Turn". If an aircraft turns away from conflicting crossing traffic, every
> additional second of turn sees the targets get closer until either they
> merge or else they *finally* get to the point of course divergence. The
> closer the targets are when an away turn is initiated, the less effective
an
> "away" turn is.
>
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?
>

I'd have probably requested a vector for traffic avoidance before the
traffic alert became necessary.

It's possible that the VFR target was indicating bad Mode C, he may have
been at a proper VFR cruising altitude and no factor for the IFR traffic at
7,000.

Chip Jones
August 19th 03, 03:40 AM
"Henry Bibb" > wrote in message
...
> I'd have *asked* for the vector by about the second call, if I couldn't
see
> him.
> I do that even in VFR with flight following.

Good point. It would have been easier to get the ball rolling in the right
direction if we had started earlier instead of waiting until an actual alert
phase.

Chip, ZTL




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Capt. Doug
August 19th 03, 03:44 AM
>Chip Jones wrote in message >The response I get is "Baron 123 is IMC, no
contact."

Howdy!

While your scenario may be right on the money, let me point out that some
pilots will claim to be IMC even when there isn't a cloud in the sky. Their
reasoning is that by doing this, it keep the onus of seperation on the
controller. We both know this isn't quite how it works, but then again, a
chimpanzee flew Mercury 7.

D.

Teacherjh
August 19th 03, 03:48 AM
.... and the N number of that rogue traffic - it wasn't N2504R perchance, was
it?

Jose

(for Email, make the obvious changes in my address)

Chip Jones
August 19th 03, 03:48 AM
"Bob Gardner" > wrote in message
news:MCe0b.184104$o%2.89767@sccrnsc02...
> This was drilled into us for shiphandling at sea...turn into the
conflicting
> traffic.

We drill this concept into ATC developmentals too. Same principle.

>Sad thing is that if you had yelled at the Baron "Negative, turn
> right immediately," the situation would have gotten worse, not better.

I thought so too

>
> I hope you tracked the intruder to his destination.
>

No I didn't. My supervisor and I has a very short discussion about doing so
and then decided we could prove nothing. Could have been bad mode C, no way
to prove he was not VMC, the baron never saw him etc etc.

Chip, ZTL




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Chip Jones
August 19th 03, 04:11 AM
"Stan Gosnell" > wrote in message
...
> "Chip Jones" > wrote in
> :
>
> <long story snipped...>
>
> > Given this traffic scenario, would any of you guys have followed my
> > suggestion to turn to a 180 heading, or was I wasting my breath?
>
> I think I would have turned in the direction you gave, since I couldn't
see
> the traffic & presumably you could, at least on radar. You have a much
> bigger picture than I do. Either he misunderstood you or he's a lot more
> arrogant than I like to think I am. If he knows he's faster than the
> converging traffic, a turn away could work, but how could he know that?
> OTOH, if you really, really want him to turn to a heading, give it as an
> instruction, not a suggestion.
>

The only problem about issuing the 180 heading as an instruction instead of
a suggestion is that I do not have separation responsibility between an IFR
and a VFR in this class of airspace. Because of that, I have to follow the
7110.65's provisions regarding safety alerts and traffic alerts, and the
7110.65 requires me to make a suggestion instead of taking control with an
instruction in this case. In fact, the 7110.65 even instructs me to use the
phraseolgy "immediately" if I offer a suggested course of action. Hence, if
your best course of action was to hold your present heading, and I suggested
this to you, I would actually have to key up and say something as ridiculous
as "N123, traffic alert [insert appropriate information here], suggest you
fly your present heading immediately for traffic!" Silly, ain't it?

The logic is that during an alert, the FAA doesn't want ATC issuing
*instructions* to a controlled aircraft that might cause it to collide with
an uncontrolled aircraft. Say I instructed a 180 turn just as the unknown
VFR made a radical turn to the west to avoid ( know it's very very
unlikely). In such a collision, the ATC instruction would likely be
identified as the *cause* of the collision and as the controller I'd be hung
for not following the book. This was drilled into me a long long time ago
when as a young pup I assigned ATC vectors to a VFR aircraft in distress
(IFR pilot in VFR-only airplane stuck on top in winter clag looking for a
friendly airport). Eventually I vectored the pilot down into an airport
safely and then got reamed by facility management for not *suggesting* the
vectors instead of assigning them. My chewing for that event went something
like this- "Good job Chip. The pilot called to say thanks- he wants to buy
you a beer. HOWEVER, assign ATC headings contrary to the 7110 again, you
moron, and you will be decertified...you could have killed that guy."

Chip, ZTL




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Chip Jones
August 19th 03, 04:39 AM
"Ben Jackson" > wrote in message
news:EQf0b.149627$Oz4.41062@rwcrnsc54...
> In article >,
> Chip Jones > wrote:
> >
> >In the most professionally bored voice I can muster, I key up and say
"Baron
> >123, traffic alert, traffic two o'clock, two miles converging from the
right
> >indicating 7000, suggest you turn right heading 180 immediately."
>
> Why did it get that far?

First of all, I had about fifteen airplanes on frequency. Mentally I was
gearing up for the wad of Atlanta departures that were getting ready to
launch (indeed were beginning to check on freq) and how the weather was
going to impact the departure push. I also had other IFR irons in the fire.
For example, I had two IFR's inbound to JZP and I was blocking for an
approach at 47A (which conflicts with JZP). I was mentally trying to get a
plan working for sequence into JZP while I was making that final
position-relief traffic scan. To me, the VFR target represented a very low
priority traffic call at six miles and 400 feet, especially since I don't
have separation responsibility between IFR and VFR traffic in thsi airspace.
I *do* have an air safety obligation that trumps all of my separation
responsibilities, but at six miles, and even at four miles, I did not
recognize that this situation was going to deteriorate from a routine
traffic situation into an alert situation with co-altitude traffic.

>If I'm the Baron I'm thinking, "I can't see
> the traffic, I won't see the traffic in IMC, why is this guy waiting
> for me to spot this plane?"

I suppose he could have requested a vector at the first or second call. I
was waitng for him to spot the traffic because that's what happens between
VFR and IFR traffic in this airspace. See and avoid.

>If you *believed* that he was really in
> the soup, why not just pretend the VFR target was a lost-comms IFR
> guy and gotten the Baron out of the way?

I didn't believe that the VFR was in the soup until he got co-altitude with
the IFR guy who had reported twice that he was IMC at 7000. I see an
unknown VFR target, I assume the pilot is complying with FAR's. In this
case, I can't prove that he wasn't.

>
> Plus if two aircraft are 2 miles apart and you turn one 90 degrees,
> by the time the turn is completed they will have both covered a mile.
> My mental image of this is that you're turning a situation where the
> two course lines would converge to a sharp point into a situation
> where they would converge in a nice rounded corner.
>

I disagree with you here. I do not use the phraseology "immediately" unless
I am worried about an imminent collision. In 13 years of ATC, I have used
"immediately" probably less than twenty times. In order for the baron to
slip behind the VFR, he did not need to turn 90 degrees, he only needed to
turn 45 to 50 degrees right. I assumed that combining "immediately" with a
suggested 80 degree right turn, there was the highest probability of a
successful outcome for the Baron. In the event, the left turn of 20 or 30
degrees that the Baron pilot executed in the event was insufficient to keep
his target from merging with the intruder.

Chip, ZTL





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BTIZ
August 19th 03, 04:59 AM
I've read all the other comments posted so far.. pretty much a 50/50 split
in options..

As an IFR pilot, my first reaction would be to take the ATC suggested turn
I'm IFR so the bozo must be too, but "Monday morning" says to initially turn
away from the traffic.. not towards, at the 2 O'clock and 2 mile call, based
on the turning radius of the Baron at 180knts TAS plus, the turn away would
give him a little more free distance before possible collision and more time
to loose a little altitude. And based on the Baron's speed being a tad
faster than the Cessna Spam Can variety aircraft, the extra speed may pull
you out in front.

Turning into the traffic (point your nose at his tail, you'll miss 'em
theory), based on the turning radius, may put the two together sooner,
allowing less time to apply an altitude change to the solution.

If you delay the turn to late, the turning radius will kill the plan.

BT (former ZBOS)

"Chip Jones" > wrote in message
...
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in
> Atlanta. Here's the deal.
>
> I was working a Center departure sector mixing Atlanta terminal departures
> of every ilk and kin with enroute overflight traffic north of metro
Atlanta.
> The sector weather was typical summer MVFR down here- lots of convection,
> hazy, hot, humid etc with building thunderstorms here and there impacting
> the sector. I had received my briefing from the previous controller and
had
> just assumed responsibility for the airspace. Part of my technique is to
do
> one more quick traffic scan *after* I take over (while the previous
> controller is still at hand) to ensure we didn't fumble a situation while
we
> changed the guard.
>
> I am working a Baron IFR at 7000 flying from Chattanooga TN to Charleston
> SC, on course heading of about 110 or so. Doing my scan, I see he has an
> IFR off the nose about 15 miles at 6000 and another IFR guy crossing from
> the NE at 8000 and 20 miles, so he is separated. I notice additional
> traffic for this guy, a VFR indicating 6600 about six miles south, heading
> about 055 or so, converging with him. I ask the previous controller if
> she had issued traffic, she said she hadn't.
>
> I made the traffic call.. "Baron 123, VFR traffic one to two o'clock, six
> miles, northeast bound converging, altitude indicates six thousand six
> hundred." The response I get is "Baron 123 is IMC, no contact."
>
> I make a few unrelated routine calls to other traffic, keeping an eye on
> this VFR target. His Mode C indicates that he is in a climb, and the
> conflict alert activates (both data blocks begin to flash). I make
another
> call at four miles. "Baron 123, your traffic now two o'clock, four miles,
> northeast bound, altitude indicating six thousand niner hundred VFR,
> converging right to left." The Baron responds "123 is IMC, no contact."
> The situation now has my undivided attention.
>
> At three miles converging (next update), the traffic is indicating 7000.
> The next update, the traffic is still at 7000. This guy is flying VFR
where
> one of my IFR's is IMC. I swing into alert mode. The target slashes are
a
> mile long each and the radar display is delayed a bit from actual position
> so these guys are getting close and closing fast. The Baron needs to yank
> it right most ricky tic and get behind this guy.
>
> In the most professionally bored voice I can muster, I key up and say
"Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the
right
> indicating 7000, suggest you turn right heading 180 immediately." The
Baron
> pilot says "We're turning left to 090, no contact." I then watch as the
> Baron swings into a left turn, prolonging the collision vector another
> minute. His left turn away from the traffic puts him wing high with
closing
> traffic off the right side. The Baron also descends four hundred feet
> during the maneuver as the targets merge. To me, this looks remarkably
like
> a TCAS maneuver because of the altitude change. I key up and say "N123,
are
> you TCAD equipped, do you have traffic avoidance avionics?" He gives me a
> curt "Negative, we do not have the traffic." The targets have merged
thanks
> to the left turn, and I cannot distinguish the one from the other.
Anything
> I say now about the traffic would be a dangerous guess because I have lost
> the flick between these two aircraft. Instead of responding to the Baron,
I
> issue a vector to the IFR traffic at 6000 to get him away from Baron 123
> (who is now well below assigned IFR altitude). At the next position
update,
> I have tail to tail between the baron and the VFR. I tell the Baron,
> "Traffic no factor, maintain 7000." He responds "We never saw him..."
[The
> unknown SOB in the VFR remains at 7000 for the next fifty miles- his
profile
> never changed and I have every reason to believe that he never saw the
IFR,
> IMC Baron].
>
> My question for the group is about the Baron pilot's decision to disregard
> my suggestion to yank it towards the traffic and instead to turn away from
> him. From a controller's perspective, the quickest way to achieve "Oh
Sh*t"
> lateral separation with crossing traffic is to aim one airplane right at
the
> other. The idea is that as both aircraft are moving through space, the
> maneuvering aircraft is steering for a point where the traffic *used* to
be
> but no longer is. Once the nose of the turning aircraft swings through
his
> traffic's vector, every additional second buys additional separation.
When
> we do this with IFR traffic, we call this a "Wimpy Crossover" or a "Bubba
> Turn". If an aircraft turns away from conflicting crossing traffic, every
> additional second of turn sees the targets get closer until either they
> merge or else they *finally* get to the point of course divergence. The
> closer the targets are when an away turn is initiated, the less effective
an
> "away" turn is.
>
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?
>
> Chip, ZTL
>
>
>
>
>
>
>
>
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Chip Jones
August 19th 03, 05:33 AM
"Roy Smith" > wrote in message
...
> "Chip Jones" > wrote:
> > Here's the deal.
>
> An interesting choice of words :-)

Ya well, as we say in Class E between IFR's and VFR's, "no dent, no deal".

>
> Hard to say for sure, but I can offer a few insights from my own
> experiences. As a general rule, if the controller says, "immediately",
> I put my life in his hands, follow orders, and ask questions later.
>
> I've only once heard the phrase "traffic alert". I was IFR, the
> controller was not talking to the other guy. It was not solid IMC, but
> there was plenty of IMC around. I can only guess the other guy was not
> legal VFR.

I don't routinely have to issue traffic alerts either. Usually this sort of
call eventually results in "traffic in sight, thanks Center".


>
> In this case, the controller did not issue a suggested heading. My
> response was to turn 90 degrees away from the direction the traffic was
> being called. I can certainly see your point where turning directly
> into the traffic would have put me behind him, but that wasn't my
> instinctive reaction.

I agree it is counter intuitive, and no matter what the controller is safely
on the ground regardless of where the pilot ends up. Not trying to be
cynical, either.

>
> I suspect your traffic call may have been by the book, but on the other
> hand, it was probably too verbose to really be useful to the pilot. I'm
> guessing that with each successive traffic call leading up to the alert,
> the pilot was getting increasingly antsy about the unseen traffic, and
> already working out an escape plan -- "bad stuff to the right, I gotta
> get left, away from the danger". All it took was hearing the words
> "traffic alert" to trigger that plan into action.

Thanks for the insight Roy- I follow you.

>
> I just timed how long it took me to calmly read the above clearance.
> Seven seconds between "traffic alert" and "heading 180". At standard
> rate, the guy's already 20 degrees into his left turn before he knows
> you want him to turn right (and I'm not sure I would limit myself to
> standard rate in response to a traffic alert).

I'm betting that's exactly how it went down. I did not observe the Baron's
maneuver until well after it began, so I can't really judge when it began.
I didn't even catch the altitude bust until a couple of updates later.
You're right, he was probably ready to execute a maneuver as soon as he got
the TA.

> More than the physics of
> changing heading, consider the human factors -- he's already made a
> decision and acted on it. He's already made the mental leap from
> obeying instructions to acting on his own. It's not going to be easy to
> get him back into the fold quickly.

Well the PIC was definitely decisive in the event. He didn't bandy any
words, and it was clear that he was set on the left turn because he didn't
hesitate one instant when he told me he was turning left.

>
> My guess is, by-the-book or not, a better way to say it might have been,
> "Barron 123, traffic alert, immediate left turn, heading 180". Get it
> right up front what you want the guy to do.


That's good advice. I'll put that in the bag of tricks.

>
> I fully understand the reason the book wants the phrasing the way it
> does. It's the PIC's decision, and the controller is just feeding the
> PIC information which will let the PIC make an informed decision. The
> problem is, I don't think it works that way in real life. It's hard
> enough working CPA problems (Closest Point of Approach; do they call it
> that in the ATC world?) looking at a screen or a plotting sheet. It's
> damn near impossible in your head with nothing better than an O'Clock
> traffic call, some dubious WCA, an unknown speed and cardinal heading on
> the target, and no formal training.

I can't even imagine. We don't call it CPA. We call it Point of
Convergence down here. Dunno if that is FAA standard.

>
> PIC-correctness, legality, and liability issues aside, the fact is the
> controller is the one with the best picture of what's going on, and it
> makes the most sense for the controller to take charge and issue an
> unambigious instruction, with no extraneous information to get in the
> way of communicating the one thing you really want to communicate: which
> way to turn.

No doubt about that. I will point out that when I suggest something on
frequency like in this event, I do use the command voice. I don't hesitate
on the radio when I am working airplanes. The only difference in my
transmission between a suggestion and an instruction is the word "suggest".
Otherwise I try to make it sound calm but imperitive.

>
> It's a pity there's no mechanism to plan stuff like this a little
> further in advance. At the 5-mile point, it would be nice if I could
> hear, "Hold current heading for now. If you don't see him in another 3
> miles, I'm going to turn you left to pass behind him". Does "the book"
> allow for such a conversation?

If you ask for it, certainly. And I have been known to issue timely ATC
instructions to IFR aircraft to avoid VFR aircraft in Class E, which is
stretching the rules but can be justified as "good judgement". I find it
easier to do this between a known VFR and IFR rather than between an IFR and
an unknown intruder.

In the actual event though, I did not recognize that this particular
situation was developing into a close call until after it was going down.


[snipped]

>
> Think about what was going on from the pilot's perspective. You kept
> telling him, "Something bad might be happening soon. I know the best
> way to deal with it, but I won't tell you what it is yet. Don't worry,
> though, at the last possible second I'll clue you in on the plan and
> then expect you to react immediately".

Well, I can see how the pilot could have that perspective. However, I
truely didn't know the best way to deal with it (south vector) until about
four miles because the VFR was maneuvering vertically according to his mode
C. I was banking that the VFR and the IFR would see and avoid if I only
gave the IFR a few good traffic calls. (Wrong!) This event occurred on a
Sunday around 1300L in Class E about 50 miles NE of ATL. This airspace sees
an awful lot of unknown VFR's because it is convenient to the Atlanta
terminal area, is outside of Tracon airspace (and the Class B rings) and is
a good place for the various flights schools at the satellite fields like
RYY, LZU, 47A and PDK to conduct flight training without getting a KingAir
or Citation enema. (You can't swing a dead cat inside the terminal area
without hitting a VFR target on a Sunday afternoon). I could have vectored
the Baron early "for traffic" only to have this unknown VFR swing back
around towards Atlanta and right at him or something.

>
> Well, anyway, that's my take on it. Other people will probably have
> different opinions.

No doubt, but as always I do appreciate your take.

Chip, ZTL




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Chip Jones
August 19th 03, 05:43 AM
"Capt. Doug" > wrote in message
...
> >Chip Jones wrote in message >The response I get is "Baron 123 is IMC, no
> contact."
>
> Howdy!
>
> While your scenario may be right on the money, let me point out that some
> pilots will claim to be IMC even when there isn't a cloud in the sky.
Their
> reasoning is that by doing this, it keep the onus of seperation on the
> controller. We both know this isn't quite how it works, but then again, a
> chimpanzee flew Mercury 7.
>

Good point, D. I've actually seen a talking Jackass work an ATC sector down
here, now that you mention it. :-)

Chip, ZTL




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Chip Jones
August 19th 03, 06:17 AM
"blanche cohen" > wrote in message
...
> Um....Bob & Chip...could you explain in more detail the reason
> for the "turn into traffic"? I'm having problems visualizing
> it. And I have the most horrible feeling that someday I'll run
> in the same problem and want to understand it.
>

To keep it simple, imagine two aircraft converging at 90 degree right
angles. One is heading northbound, one is heading east bound, on collision
courses. Assuming a vertical solution is not a viable option, the fastest
way to achieve separation is to turn one aircraft decisively behind another
aircraft. This kind of turn involves the nose of one aircraft swinging
through the vector (ie- the projected path) of the other aircraft. This
requires a turn towards the other guy. The closer the two aircraft are to
one another when the maneuver is initiated, or the narrower the angle of
convergence, the more of a turn is required. Aircraft types, winds aloft,
other traffic in the scenario etc all play a factor in who gets turned and
how much of a turn is needed. Generally, if all things are considered
equal, one turns the slower aircraft behind the faster aircraft.

This kind of turn can be be counter intuitive to the pilots involved. In
the case of the aircraft heading 090 and the aircraft heading 360, let's
suppose that I issue traffic traffic and then initiate an separation
resolution. To the north bound aircraft, I call traffic at ten o'clock and
ten miles, eastbound co-altitude. I then initiate a vector to put the north
bound airplane behind the east bound airplane. "Turn left heading 310,
vectors behind traffic." To the pilot, I have just issued a turn right into
the traffic I just called. In the controllers mind, I have taken other
factors into play. The east bound aircraft has a tailwind, so the 310
vector will aim the northbound guy into the wind, slowing him down. The
northbound guy was slower anyway. There is more traffic to the south,
precluding a southerly turn to the eastbound aircraft etc etc etc. The
pilot may say "Say again Atlanta? Isn't that where my traffic is?"

The very very basic idea is that assuming I have enough time to aim the nose
of one airplane at the point in space that the other airplane occupies when
I inititate the maneuver, then by the time his nose actually gets there, the
other aircraft has moved on. This assures that neither aircraft will hit
(assuming they don't get together in the turn.) Lots of variables too.

Chip, ZTL





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Peter Duniho
August 19th 03, 08:29 AM
"Chip Jones" > wrote in message
...
> [...]
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?

I can't imagine why the Baron didn't turn as you suggested, assuming he
really was IMC. Roy's suggestion that the Baron pilot started the turn
before hearing your suggested vector may be the case, but it seems foolish
of the Baron pilot to make a decision to turn one direction or another
without any input from ATC, if in IMC.

As for whether the other traffic was VFR or not, that's less clear. The
Baron pilot stopped reporting IMC (at least according to your description)
well before the two planes actually converged. It's entirely possible the
Baron did wind up flying out of a cloud, and from that point on was actually
looking for the other traffic. Actually, I suppose if the Baron wound up in
VMC, that might explain the direction he turned and why he was willing to
make a turn without ATC advice.

In any case, keep making those "vectors for traffic" suggestions. Most
pilots, if IMC with no hope of seeing the other traffic, would listen to
you. I know I would.

Pete

Martin
August 19th 03, 10:06 AM
Best damn thread in this newsgroup in a while, on topic, interesting
and no one being overly pugnacious. That said...

I think almost everyone can agree on a few basic facts:
-The turn into traffic idea, with appropriate spacing, is a good one
-If a controller suggests an "immediate" change in course... do it
-Traffic avoidence sooner rather than later is best

All that together makes it pretty clear, someone already mentioned
that once the pilot heard "traffic alert" they probably +started their
avoidence right away. without waiting the extra 4 or 5 sec to hear out
the controller... I have no doubt that is what I would do.
So I guess my suggestion to controllers in this situation is to spit
out the vector asap, something like "N123A traffic alert, right turn
to 180 immediately is suggested"... I know it sounds choppy, but I
wouldnt wait a second longer after hearing "traffic alert" to start
what I think is a logical turn. Having "right turn" being the next
words should start the process correctly.
Chip youre a good man, many controllers (well the ones I know here in
the northeast at least) tend to just say "f**king pilot" and move on,
youre actually trying to get a pilots point of view. I hope you got a
better sense of what we're thinking up there, I certainly learned
quite a bit from your posts... im just stoaked about this thread lol.

pilotjww
August 19th 03, 11:35 AM
Nice thread.

Turning towards the tail of the traffic is natural for me, and has always
worked so far, especially when VMC. I share the sailing experience of the
the earlier posters.

I mostly fly IFR. While IMC, I have experienced several ATC-supplied traffic
alerts for VFR traffic, but no visual contact.

I also recall traveling IMC (in and out of CU) and briefly observing
crossing traffic slightly above my altitude, with NO traffic call out. When
I queried ATC, they didn't have him, so the traffic may have not been using
a transponder. I was lucky to miss.

A small nit: I fly a low-wing, and any ATC traffic alert inside of 4-5 miles
and below my altitude will be hard to see without some maneuvering to remove
my airplane's nose or wing from line-of sight. I expect even a high-wing
will also have at least the problem of traffic under the nose. I get a lot
of these alerts, where the traffic is a thousand or more below me, often
unverified, and I find them useless.

But if the traffic is approaching my altitude and is under my nose or wing,
I need to maneuver anyway to see it, so will appreciate a vector from ATC to
both see and avoid.

T-Boy
August 19th 03, 11:53 AM
In article >,
says...
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?

IFR, IMC and no contact, i'd put my trust in you. I'd be a
*bit* concerned about you letting me get to within two miles of
the traffic though.

--
Duncan

T-Boy
August 19th 03, 11:54 AM
In article >,
says...

PS: did you catch up with the "VFR" :) - traffic.

--
Duncan

Steven P. McNicoll
August 19th 03, 12:01 PM
"Newps" > wrote in message
news:N3h0b.192923$Ho3.26290@sccrnsc03...
>
> That was cool. I would tag up the "VFR" pilot and run him thru FSDO.
> You have proof he was IMC.
>

You'd have proof that he was in IMC only if he had collided with the guy at
7000 in IMC.

Gary L. Drescher
August 19th 03, 12:44 PM
"Chip Jones" > wrote in message
...
> This kind of turn can be be counter intuitive to the pilots involved.

Yup. It was to me until I gave it more thought.

> In
> the case of the aircraft heading 090 and the aircraft heading 360, let's
> suppose that I issue traffic traffic and then initiate an separation
> resolution. To the north bound aircraft, I call traffic at ten o'clock
and
> ten miles, eastbound co-altitude. I then initiate a vector to put the
north
> bound airplane behind the east bound airplane. "Turn left heading 310,
> vectors behind traffic."

The "vectors behind traffic" phrase sounds very useful. It concisely
explains to the pilot, in real time, why the counterintuitive instruction
actually makes sense.

Thanks for posting this. If I'm ever in such a situation, having thought
about it beforehand might help me avoid wasting a second or two trying to
figure it out.

--Gary

Roy Smith
August 19th 03, 01:21 PM
In article >,
(blanche cohen) wrote:

> Um....Bob & Chip...could you explain in more detail the reason
> for the "turn into traffic"? I'm having problems visualizing
> it. And I have the most horrible feeling that someday I'll run
> in the same problem and want to understand it.
>
> thanks
>

That one's easy.

Let's say you've got two objects moving in space (doesn't matter if
they're airplanes, boats, or cars). They are on intercept courses,
something like this:

#1------>

^
|
|
#2

Assume for the moment you're object #2, trying to decide how to avoid
hitting #1. Assume that #1 is going to keep moving at a constant speed
and direction. Further assume that the problem is reduced to 2D (i.e.
nobody can change altitude).

You've basicly got 4 choices: you can speed up, slow down, turn left, or
turn right. In boats or planes, speed changes usually happen pretty
slowly, so they're really not effective for short-term collision
avoidance. This leaves you with turn left or turn right.

Let's say I make an 45 degree turn to the right (away from the target).
Now the situation is this:

#1------>

^
/
/
#2

Quick, is this an intercept situation? Can you work out in your head if
#2 will cross in front of #1? They're still moving towards each other,
so it's hard to tell.

But, what if #2 turned to the left, toward the target? Now you've got:

#1------>

^
\
\
#2

It should be obvious in the picture above that #2 is going to pass
behind #1. Look at the arrow heads (the lengths of the arrows are how
far each target will move in, say, 1 minute). By the time #2 gets to
the head of its arrow, #1 has already moved from it left side to its
right side.

The basic rule is that if you're aiming right at a crossing target,
you'll never hit it, because while you're moving towards it, it's moving
cross-wise to you and will move away from where you're aiming. The
correlary of this is that if you *want* to hit the target, you need to
lead it (this is the "firing solution" stuff they're always doing in
submarine movies when they launch a torpedo).

Leland Vandervort
August 19th 03, 01:51 PM
On Tue, 19 Aug 2003 11:44:03 GMT, "Gary L. Drescher"
> wrote:

>"Chip Jones" > wrote in message
...
>> This kind of turn can be be counter intuitive to the pilots involved.
>
>Yup. It was to me until I gave it more thought.
>

Actually, to me it seems quite logical and would have been my initial
reflect to turn TOWARDS the conflicting traffic, since the whole
purpose of the exercise would be to change the constant bearing of
closure.. turning away from it will only slow the rate of bearing, not
necessary change the angle (as viewed from overhead both, not as in
"clock" positions from the pilot's perspective).. turning towards it
will increase the rate briefly until the vector angle is depassed and
then it will widen again. Of course if the other traffic does the
same thing, then you're going from a constant relative 90 degree
closing bearing to a constant relative head-on closing bearing which
will also be a bad thing... of course in this particular case the
other [unidentified] aircraft was seen to maintain his course.

Leland

Snowbird
August 19th 03, 02:41 PM
(Ben Jackson) wrote in message news:<EQf0b.149627$Oz4.41062@rwcrnsc54>...
> In article >,
> Chip Jones > wrote:
> >In the most professionally bored voice I can muster, I key up and say "Baron
> >123, traffic alert, traffic two o'clock, two miles converging from the right
> >indicating 7000, suggest you turn right heading 180 immediately."

> Why did it get that far? If I'm the Baron I'm thinking, "I can't see
> the traffic, I won't see the traffic in IMC, why is this guy waiting
> for me to spot this plane?"

Ben, you raise a good point, but if I'm the Baron, I would have been
re-stating "Baron 1234 is IMC" and at the second call "negative contact,
we're IMC, *request vector for traffic*.

IMO the PIC has a responsibility to be pro-active here.

> If you *believed* that he was really in
> the soup, why not just pretend the VFR target was a lost-comms IFR
> guy and gotten the Baron out of the way?

Just to point out here, Chip isn't working the "VFR" target, he
has no idea what this guy's intentions really are. Coulda been
an instrument training flight climbing up to get cool and about
to start practicing steep turns or the like. Kinda complicates
getting other people out of the way, I would think.

Cheers,
Sydney

Snowbird
August 19th 03, 02:49 PM
"Capt. Doug" > wrote in message >...
> >Chip Jones wrote in message >The response I get is "Baron 123 is IMC, no
> contact."

> While your scenario may be right on the money, let me point out that some
> pilots will claim to be IMC even when there isn't a cloud in the sky. Their
> reasoning is that by doing this, it keep the onus of seperation on the
> controller.

Hi Doug,

There's also the vis. factor. If it's hazy and you're flying towards
the sun, you can't see a durn thing even if there isn't a cloud out
there. You're flying on instruments; isn't that properly described
as "IMC" with no funky legal reasoning behind it?

OTOH, a plane flying perp. or away from the sun can legitimately
see 3+ miles

IIRC the Baron was flying 110, early a.m., perhaps this is possible?

Cheers,
Sydney

Snowbird
August 19th 03, 02:50 PM
(Teacherjh) wrote in message >...
> ... and the N number of that rogue traffic - it wasn't N2504R perchance, was
> it?

How does anyone know? Chip wasn't working it, the Baron didn't
see it

Cheers,
Sydney

Stan Gosnell
August 19th 03, 03:08 PM
"Chip Jones" > wrote in
:

> The only problem about issuing the 180 heading as an instruction
> instead of a suggestion is that I do not have separation
> responsibility between an IFR and a VFR in this class of airspace.
> Because of that, I have to follow the 7110.65's provisions regarding
> safety alerts and traffic alerts, and the 7110.65 requires me to make
> a suggestion instead of taking control with an instruction in this
> case. In fact, the 7110.65 even instructs me to use the phraseolgy
> "immediately" if I offer a suggested course of action. Hence, if your
> best course of action was to hold your present heading, and I
> suggested this to you, I would actually have to key up and say
> something as ridiculous as "N123, traffic alert [insert appropriate
> information here], suggest you fly your present heading immediately
> for traffic!" Silly, ain't it?

Any similarity between logic and government regulations is purely
coincidental and completely unintended. But if you ever see me heading for
another aircraft, please point me somewhere else, whatever phraseology you
can come up with that will satisfy 7110.65. If we have a midair, you'll be
down there blameless in the FAA's eyes, but I'll come back and haunt you.
;-)

--
Regards,

Stan

Leland Vandervort
August 19th 03, 03:16 PM
On 19 Aug 2003 06:50:30 -0700, (Snowbird)
wrote:

(Teacherjh) wrote in message >...
>> ... and the N number of that rogue traffic - it wasn't N2504R perchance, was
>> it?
>
>How does anyone know? Chip wasn't working it, the Baron didn't
>see it

Syd, I think this one was referring (rather humourously) to the other
thread about an aircraft which was stolen ;-) Nevertheless, it would
have been a cool coincidence if it were...

Cheers,

Leland

Peter R.
August 19th 03, 03:26 PM
Snowbird ) wrote:

>
> (Teacherjh) wrote in message news:
> > ... and the N number of that rogue traffic - it wasn't N2504R perchance, was
> > it?
>
> How does anyone know? Chip wasn't working it, the Baron didn't
> see it

I believe he was referring to the stolen Cessna 182 thread, where the 182's
N number was N2504R. Sort of a funny scenario, having the stolen C182 be
involved in this thread, too.



--
Peter

Ron Natalie
August 19th 03, 03:56 PM
"Snowbird" > wrote in message om...
> Jesu! I hate pilots who fly illegal IMC. Making the most charitable
> interpretation possible, it's possible that the Baron was in spotty
> IMC and the other pilot climbing through a hole, and that his Mode C
> was off.

Or the visibility was right at three miles and the sun was in the Baron
pilot's eyes, etc...

Chip Jones
August 19th 03, 04:36 PM
"Dr. Anthony J. Lomenzo" > wrote in message
...
[snipped]
>
>
> Note to Chip! Chip, your name rings a bell...didn't you have a rather
> elaborate ATC website { I could have the wrong person but your sector
> mention after your name [ZTL] rings a bell ... as well as a secondary
> website dealing with flight safety [read: crash] investigation issues?

Not me. :-)

Chip, ZTL




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Michael 182
August 19th 03, 05:03 PM
"Martin" > wrote in message
om...
> Chip youre a good man, many controllers (well the ones I know here in
> the northeast at least) tend to just say "f**king pilot" and move on

While we are (at least tangentially) on the subject of good controllers...

I was picking my way through a line of thunderstorms west of Huntsville a
few weeks ago. I have stormscope, but no radar. In and out of IMC, and the
stormscope is starting to look like a video game screen. The controller
(Memphis Center, I believe) was unbelievably helpful. He was working a dozen
or so planes, offering quick deviations left and right, while at the same
time responding to calls for info from pilots like me. I ended up (with his
blessing, of course) descending 10,000 feet in steep turns to avoid a storm
ahead of me, turning 50 degrees north to go under the clouds in a gap he and
I agreed was there, and was past the weather in ten minutes.

If I wanted to commend his work to his supervisor, how would I do so? He did
a great job - every handoff was accompanied by "123.45, Great job today!
Thanks"


Michael

Dr. Anthony J. Lomenzo
August 19th 03, 05:07 PM
Chip Jones wrote:
>
> "Dr. Anthony J. Lomenzo" > wrote in message
> ...
> [snipped]
> >
> >
> > Note to Chip! Chip, your name rings a bell...didn't you have a rather
> > elaborate ATC website { I could have the wrong person but your sector
> > mention after your name [ZTL] rings a bell ... as well as a secondary
> > website dealing with flight safety [read: crash] investigation issues?
>
> Not me. :-)
>

Naturally instead of my doing the legwork first and digging it up, I
relied on memory [faulty in this case..] and sure enough, wrong person,
this person was out of Chicago and not the Atlanta region. Besides the
real-deal [and like others here who duly hold FAA tickets, presently or
back when...] I enjoy the flight sims inclusive of ATC sims. My comments
as to the adjunctive value of flight sims to the real deal is fairly
well known and I was/am one of those who tend to get away from the 'it's
a game' theme or mind-set of flight sims and prefer, if you will, the
flight sims as an adjunctive learning tool to the real McCoy...the
limitations [big bucks motion sims] notwithstanding.

It struck me however that not only are flight sims utilized by the
commercial folks and Uncle Sam [et al] to boot in an adjunctive capacity
but for some 12 to 16 weeks of initial professional ATC training, ATC
folks go to Oklahoma City [so I've read anyway] and use Doc Wesson's ATC
'SIMULATION' programs for their initial professional training.

In any event, I emailed this controller and he had an excellent website
tutorial on real-deal ATC and I recall commenting that I personally
would not want that kind of daily pressure cooker responsibility or
nightmares about 'deals' and making instant judgment calls in an often
hectic ['chaotic' atmosphere perhaps at some of the larger airports]
atmosphere that can effect so many lives. I daresay that the ATC
brethren perhaps have a high incidence, inter alia, of stomach ulcers!
Whew! I respect their profession and give them much credit but it's a
profession that I personally would not want to perform. I'll leave the
manipulation(s) of those separation issues and emergency actions or the
proverbial "string of pearls" goal to those professionals who can do it
and do it well. But, bottom line, I'm sure glad they are there!

Doc Tony

> Chip, ZTL
>
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Bob Gardner
August 19th 03, 05:21 PM
In a seagoing context (ships are bigger than airplanes), when you turn away
from crossing traffic you present the side of the ship to the
intruder...lots of vulnerability. When you turn toward the crossing traffic
you present a smaller target for a shorter time.

Bob Gardner

"blanche cohen" > wrote in message
...
> Um....Bob & Chip...could you explain in more detail the reason
> for the "turn into traffic"? I'm having problems visualizing
> it. And I have the most horrible feeling that someday I'll run
> in the same problem and want to understand it.
>
> thanks
>

Dr. Anthony J. Lomenzo
August 19th 03, 05:43 PM
"Dr. Anthony J. Lomenzo" wrote:
>
> Chip Jones wrote:
> >
> > "Dr. Anthony J. Lomenzo" > wrote in message
> > ...
> > [snipped]
> > >
> > >
> > > Note to Chip! Chip, your name rings a bell...didn't you have a rather
> > > elaborate ATC website { I could have the wrong person but your sector
> > > mention after your name [ZTL] rings a bell ... as well as a secondary
> > > website dealing with flight safety [read: crash] investigation issues?
> >
> > Not me. :-)
> >
>
> Naturally instead of my doing the legwork first and digging it up, I
> relied on memory [faulty in this case..] and sure enough, wrong person,
> this person was out of Chicago and not the Atlanta region. Besides the
> real-deal [and like others here who duly hold FAA tickets, presently or
> back when...] I enjoy the flight sims inclusive of ATC sims. My comments
> as to the adjunctive value of flight sims to the real deal is fairly
> well known and I was/am one of those who tend to get away from the 'it's
> a game' theme or mind-set of flight sims and prefer, if you will, the
> flight sims as an adjunctive learning tool to the real McCoy...the
> limitations [big bucks motion sims] notwithstanding.
>
> It struck me however that not only are flight sims utilized by the
> commercial folks and Uncle Sam [et al] to boot in an adjunctive capacity
> but for some 12 to 16 weeks of initial professional ATC training, ATC
> folks go to Oklahoma City [so I've read anyway] and use Doc Wesson's ATC
> 'SIMULATION' programs for their initial professional training.
>
> In any event, I emailed this controller and he had an excellent website
> tutorial on real-deal ATC and I recall commenting that I personally
> would not want that kind of daily pressure cooker responsibility or
> nightmares about 'deals' and making instant judgment calls in an often
> hectic ['chaotic' atmosphere perhaps at some of the larger airports]
> atmosphere that can effect so many lives. I daresay that the ATC
> brethren perhaps have a high incidence, inter alia, of stomach ulcers!
> Whew! I respect their profession and give them much credit but it's a
> profession that I personally would not want to perform. I'll leave the
> manipulation(s) of those separation issues and emergency actions or the
> proverbial "string of pearls" goal to those professionals who can do it
> and do it well. But, bottom line, I'm sure glad they are there!
>
> Doc Tony


ADDENDUM....

I suppose I should add a qualifier here lest I get an email to the tune
of 'Hey, Doc, flying, be it a 152 or a Trip' 7 is 'responsibility',
yes?' and most assuredly true enough but please note that in my comments
about ATC the operative words were 'daily pressure' and that is the part
that I would just as soon do without in terms of such 'daily' pressures
being the means of my livelihood.

Explains too, no doubt, why I'm not a commercial ATP pilot by
profession although I'll say this and recognizing that both carry an
enormous amount of responsibility : If I had the proverbial magic wand
and could wave same and thus have the requisite savvy and experience for
'either' the ATP ticket and gig --versus-- an ATC controller at a
'major' hub, I'd probably choose the ATP ticket because given the choice between flight management
monitoring once at cruise altitude with a Triple 7 --versus-- sitting in
the hot seat at 24/7 JFK, LAX, ATL and the other pressure cooker TRACONS
and related ATC heavy traffic get-it-done assignments, I'd take the
flight deck of a Jumbo or Triple 7. I mean you can get 'some' break and
there is the right seat FO to boot! But ATC every day with NO mandated
FAA time-off/no-fly regs [for the ATP], nahhhhh.

Doc Tony

>[i]
> > Chip, ZTL
> >
> > ----== Posted via Newsfeed.Com - Unlimited-Uncensored-Secure Usenet News==----
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August 19th 03, 05:51 PM
Chip Jones wrote:

> >
>
> I disagree with you here. I do not use the phraseology "immediately" unless
> I am worried about an imminent collision. In 13 years of ATC, I have used
> "immediately" probably less than twenty times. In order for the baron to
> slip behind the VFR, he did not need to turn 90 degrees, he only needed to
> turn 45 to 50 degrees right. I assumed that combining "immediately" with a
> suggested 80 degree right turn, there was the highest probability of a
> successful outcome for the Baron. In the event, the left turn of 20 or 30
> degrees that the Baron pilot executed in the event was insufficient to keep
> his target from merging with the intruder.
>
> Chip, ZTL

I guess had he been above 10,000 you could have used the merging target provisions of
the 7110.65?

Scott Lowrey
August 19th 03, 07:00 PM
"Chip Jones" wrote:
> The other day, I had an air traffic situation ...

Sorry to sound like a cheerleader, but this has been a great thread.
Always interesting to hear things from the ATC point of view.

BTW, Chip, do you know Don Brown? I believe he also works ZTL. As a
rookie pilot just venturing into the wide world of ATC, I've learned a
lot from his "Say Again?" columns at AvWeb.

-Scott

Steven P. McNicoll
August 19th 03, 07:31 PM
"Capt. Doug" > wrote in message
...
>
> While your scenario may be right on the money, let me point out that some
> pilots will claim to be IMC even when there isn't a cloud in the sky.
Their
> reasoning is that by doing this, it keep the onus of seperation on the
> controller. We both know this isn't quite how it works, but then again, a
> chimpanzee flew Mercury 7.
>

A chimpanzee did not fly Mercury 7. The chimpanzee "Ham" flew on
Mercury-Redstone 2 and the chimpanzee "Enos" flew on Mercury-Atlas 5.
Mercury-Atlas 7 was flown by Scott Carpenter.

Steven P. McNicoll
August 19th 03, 07:40 PM
> wrote in message ...
>
> I guess had he been above 10,000 you could have used the merging target
> provisions of the 7110.65?
>

How so?

Merging target procedures apply to radar identified aircraft.

Ben Jackson
August 19th 03, 08:11 PM
In article >,
Snowbird > wrote:
>> If you *believed* that he was really in
>> the soup, why not just pretend the VFR target was a lost-comms IFR
>> guy and gotten the Baron out of the way?
>
>Just to point out here, Chip isn't working the "VFR" target, he

I know, but it worries me that just because the VFR-in-IMC guy is
breaking the rules, the controller is left in a position where due
to regulations and habit/mindset he is unable to resolve a traffic
situation that would otherwise be routine. In software this is one
of those "can't happen" cases. You "can't" have a guy in IMC that's
not on an IFR flightplan converging with an IFR plane. So the regs
don't allow for it and anyone evaluating the situation tries to make
it fit into one of the other categories instead.

obviously no metal was bent here, but the Baron used his emergency
authority to deviate from his clearance trying to get out of the way.

--
Ben Jackson
>
http://www.ben.com/

Steven P. McNicoll
August 19th 03, 08:23 PM
> wrote in message ...
>
> "5-1-8 Merging Target Procedures
> a. Except while they are established in a holding pattern, apply merging
> target procedures to all radar identified:
>
> 1. Aircraft at 10,000 feet and above.
>
> 2. Turbojet aircraft regardless of altitude."
>

I'm familiar with the paragraph, you haven't answered my question.

Tom S.
August 19th 03, 09:48 PM
"Chip Jones" > wrote in message
...
> This kind of turn can be be counter intuitive to the pilots involved.

Yet in high speed driving school (i.e., Bondurant) they teach you to swerve
BEHIND a car coming across your path. Most drivers will just slam on the
brakes. In fact, in most every situation the vast majority of drivers will
just slam on the brakes rather than maneuver out of the way. It's the
hardest habit the driving instructors have to break (pardon the pun).

Michael
August 19th 03, 11:42 PM
"Chip Jones" > wrote
> In the most professionally bored voice I can muster, I key up and say "Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the right
> indicating 7000, suggest you turn right heading 180 immediately." The Baron
> pilot says "We're turning left to 090, no contact."
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?

Personally, I've had one of those "Immediately" calls in my life. Two
miles, converging, altitude indicates 4200 (I was IFR at 4000, in and
out of the tops). The controller suggested I descend. Instead I
climbed, figuring I could be out of the tops in just a couple of
seconds and avoid the guy visually. It was the right call - I spotted
and avoided him. My feeling was that if we crashed, I wasn't going to
have to worry about it, and if we didn't, I would claim emergency
authority. I'm betting the Baron pilot figured something similar.

Your explanation makes sense - it explains why turning into the
traffic is reasonable and not nearly as crazy as it initially sounds.
Not having a sailing background, it's the first time I've heard it.

I suspect I would have done exactly what the Baron pilot did - make a
diving left turn. A Baron is way faster than almost anything that's
going to be flying around VFR not talking to anyone, so turning away
and diving still seems like the best plan. I can certainly see what
the Baron pilot was thinking.

Michael

Mark Evans
August 19th 03, 11:49 PM
This whole thread brings back a memory from almost 20 YA. I was training for
my CFII so I was in the right seat of the c172, the "student" was in the
left, and my instructor was in the back.
We were shooting practice approaches at TOI. That day there was a broken
layer at the IAF alt. (2100') so we where in and out of IMC. We had just
shoot one of the published approaches, and where getting vectors for the
other approach when ATC vectored us with a left turn, seconds after
finishing the turn a light twin pops out of a cloud at our 10 o'clock,
flashes in front of us from left to right, with feet to spare. The "student"
was so lucky, he was under the hood and never saw anything, me? My hands
still sweat when I think or talk about it. We reported the near miss to ATC
and they had negative contact with the other plane. I am probably the most
non violent person I know, but if I ever found out who that was I swear I'd
beat the **** out of him.

Mark {still wary of cumulo-aluminous} Evans


"Chip Jones" > wrote in message
...
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in
> Atlanta. Here's the deal.
>
> I was working a Center departure sector mixing Atlanta terminal departures
> of every ilk and kin with enroute overflight traffic north of metro
Atlanta.
> The sector weather was typical summer MVFR down here- lots of convection,
> hazy, hot, humid etc with building thunderstorms here and there impacting
> the sector. I had received my briefing from the previous controller and
had
> just assumed responsibility for the airspace. Part of my technique is to
do
> one more quick traffic scan *after* I take over (while the previous
> controller is still at hand) to ensure we didn't fumble a situation while
we
> changed the guard.
>
> I am working a Baron IFR at 7000 flying from Chattanooga TN to Charleston
> SC, on course heading of about 110 or so. Doing my scan, I see he has an
> IFR off the nose about 15 miles at 6000 and another IFR guy crossing from
> the NE at 8000 and 20 miles, so he is separated. I notice additional
> traffic for this guy, a VFR indicating 6600 about six miles south, heading
> about 055 or so, converging with him. I ask the previous controller if
> she had issued traffic, she said she hadn't.
>
> I made the traffic call.. "Baron 123, VFR traffic one to two o'clock, six
> miles, northeast bound converging, altitude indicates six thousand six
> hundred." The response I get is "Baron 123 is IMC, no contact."
>
> I make a few unrelated routine calls to other traffic, keeping an eye on
> this VFR target. His Mode C indicates that he is in a climb, and the
> conflict alert activates (both data blocks begin to flash). I make
another
> call at four miles. "Baron 123, your traffic now two o'clock, four miles,
> northeast bound, altitude indicating six thousand niner hundred VFR,
> converging right to left." The Baron responds "123 is IMC, no contact."
> The situation now has my undivided attention.
>
> At three miles converging (next update), the traffic is indicating 7000.
> The next update, the traffic is still at 7000. This guy is flying VFR
where
> one of my IFR's is IMC. I swing into alert mode. The target slashes are
a
> mile long each and the radar display is delayed a bit from actual position
> so these guys are getting close and closing fast. The Baron needs to yank
> it right most ricky tic and get behind this guy.
>
> In the most professionally bored voice I can muster, I key up and say
"Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the
right
> indicating 7000, suggest you turn right heading 180 immediately." The
Baron
> pilot says "We're turning left to 090, no contact." I then watch as the
> Baron swings into a left turn, prolonging the collision vector another
> minute. His left turn away from the traffic puts him wing high with
closing
> traffic off the right side. The Baron also descends four hundred feet
> during the maneuver as the targets merge. To me, this looks remarkably
like
> a TCAS maneuver because of the altitude change. I key up and say "N123,
are
> you TCAD equipped, do you have traffic avoidance avionics?" He gives me a
> curt "Negative, we do not have the traffic." The targets have merged
thanks
> to the left turn, and I cannot distinguish the one from the other.
Anything
> I say now about the traffic would be a dangerous guess because I have lost
> the flick between these two aircraft. Instead of responding to the Baron,
I
> issue a vector to the IFR traffic at 6000 to get him away from Baron 123
> (who is now well below assigned IFR altitude). At the next position
update,
> I have tail to tail between the baron and the VFR. I tell the Baron,
> "Traffic no factor, maintain 7000." He responds "We never saw him..."
[The
> unknown SOB in the VFR remains at 7000 for the next fifty miles- his
profile
> never changed and I have every reason to believe that he never saw the
IFR,
> IMC Baron].
>
> My question for the group is about the Baron pilot's decision to disregard
> my suggestion to yank it towards the traffic and instead to turn away from
> him. From a controller's perspective, the quickest way to achieve "Oh
Sh*t"
> lateral separation with crossing traffic is to aim one airplane right at
the
> other. The idea is that as both aircraft are moving through space, the
> maneuvering aircraft is steering for a point where the traffic *used* to
be
> but no longer is. Once the nose of the turning aircraft swings through
his
> traffic's vector, every additional second buys additional separation.
When
> we do this with IFR traffic, we call this a "Wimpy Crossover" or a "Bubba
> Turn". If an aircraft turns away from conflicting crossing traffic, every
> additional second of turn sees the targets get closer until either they
> merge or else they *finally* get to the point of course divergence. The
> closer the targets are when an away turn is initiated, the less effective
an
> "away" turn is.
>
> Given this traffic scenario, would any of you guys have followed my
> suggestion to turn to a 180 heading, or was I wasting my breath?
>
> Chip, ZTL
>
>
>
>
>
>
>
>
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Gary L. Drescher
August 20th 03, 12:01 AM
"Chip Jones" > wrote in message
...
> In the most professionally bored voice I can muster, I key up and say
"Baron
> 123, traffic alert, traffic two o'clock, two miles converging from the
right
> indicating 7000, suggest you turn right heading 180 immediately."

A question just occurred to me, Chip. Might it not get a slightly quicker
response from the pilot if your voice sounded urgent rather than
professionally-bored? This is a human-factors question that I don't know
the answer to, but it seems plausible that an urgent tone would be helpful,
especially for the typical low-time pilot who has read about traffic alerts
but never actually received one before.

By the same token, if I get momentarily overloaded when flying IFR, I
usually avoid trying to affect an unflustered tone when I talk to ATC
(though I still try to be clear and concise, of course). Pride aside, I
figure it's better if they can tell that I'm having a little difficulty
keeping up.

--Gary

Roy Smith
August 20th 03, 12:32 AM
"Gary L. Drescher" > wrote:
> A question just occurred to me, Chip. Might it not get a slightly quicker
> response from the pilot if your voice sounded urgent rather than
> professionally-bored?

One of the most imporant things in a crisis is to stay calm, and to
project an aura of calmness so others do the same. Once you let your
voice start to show emotion, it's all over.

Didn't you ever see Apollo-13? The whole damn spaceship is falling
apart around them and they're doing their "Houston, we've got a problem"
thing in the same tone of voice they'd use to report what they had for
lunch.

> This is a human-factors question that I don't know
> the answer to, but it seems plausible that an urgent tone would be helpful

You're right, it is a human factors thing. There is a certain "calm,
cool, in command of the situation" persona that you want to project,
because that's what people react best to.

> especially for the typical low-time pilot who has read about traffic alerts
> but never actually received one before.

Quick lesson in ATC-speak. Words like "alert" and "immediately" are not
to be taken lightly.

Snowbird
August 20th 03, 02:11 AM
(Scott Lowrey) wrote in message >...

> BTW, Chip, do you know Don Brown?

Not asking in the biblical sense I hope?

Sydney

Snowbird
August 20th 03, 02:13 AM
Peter R. > wrote in message m>...

> I believe he was referring to the stolen Cessna 182 thread, where the 182's
> N number was N2504R. Sort of a funny scenario, having the stolen C182 be
> involved in this thread, too.

Got it. Me dense.

Coulda been. Shoulda tracked that sucka.

Cheers,
Sydney

Snowbird
August 20th 03, 02:16 AM
Stan Gosnell > wrote in message >...

> Any similarity between logic and government regulations is purely
> coincidental and completely unintended. But if you ever see me heading for
> another aircraft, please point me somewhere else, whatever phraseology you
> can come up with that will satisfy 7110.65. If we have a midair, you'll be
> down there blameless in the FAA's eyes, but I'll come back and haunt you.
> ;-)

Stan,

Doesn't this sound like a good title for a thriller?

"The Haunted Controller"

Best,
Sydney

Capt. Doug
August 20th 03, 02:16 AM
>Steven P. McNicoll wrote in message > Mercury-Atlas 7 was flown by Scott
>Carpenter.

Yeah, he didn't like it when I called him a Chimpanzee either.

D. :-)

Capt. Doug
August 20th 03, 02:16 AM
>Chip Jones wrote in message > Good point, D. I've actually seen a talking
Jackass >work an ATC sector down here, now that you mention it. :-)

Seems to happen everytime I request direct to OKK from JOHNN. :-)

D. (pilots vs. controllers- what a softball game that would be!)

Capt. Doug
August 20th 03, 02:16 AM
>Snowbird wrote in message > There's also the vis. factor. If it's hazy and
you're flying >towards the sun, you can't see a durn thing even if there
isn't a cloud out
> there. OTOH, a plane flying perp. or away from the sun can legitimately
> see 3+ miles

Last weekend, I flew up to North Carolina at 16,500'. I try to put one of
the local flight instructors in the seat when I can. It was a hazy summer
day, but the co-pilot of the day had no problem maintaining straight and
level, staying out of the clouds, and spotting landmarks. However, the TCAD
(traffic collision avoidance thing) would show an occassional target being
within 3 miles of us and we couldn't see them for nothing.

D.

John R. Copeland
August 20th 03, 02:30 AM
Yes, my old TCADs used to do that for me in eastern Kansas, too.
(Or maybe it was in western Missouri, I'm not too sure.)
I've not noticed it since I upgraded to a 9900BX last year, though.
---JRC---

"Capt. Doug" > wrote in message =
...
>=20
> However, the TCAD
> (traffic collision avoidance thing) would show an occassional target =
being
> within 3 miles of us and we couldn't see them for nothing.
>=20
> D.
>=20
>

Peter Duniho
August 20th 03, 02:33 AM
> wrote in message ...
> "Steven P. McNicoll" wrote:
> > Merging target procedures apply to radar identified aircraft.
>
> "5-1-8 Merging Target Procedures
> a. Except while they are established in a holding pattern, apply merging
> target procedures to all radar identified:

What McNicoll is trying to say in his oh-so-charming way is that "radar
identified" has a very specific meaning, and the VFR traffic wasn't radar
identified. Being visible on the radar scope is not in and of itself
sufficient for being "radar identified".

Pete

Teacherjh
August 20th 03, 02:53 AM
>>
Yet in high speed driving school (i.e., Bondurant) they teach you to swerve
BEHIND a car coming across your path. Most drivers will just slam on the
brakes. In fact, in most every situation the vast majority of drivers will
just slam on the brakes rather than maneuver out of the way. It's the
hardest habit the driving instructors have to break (pardon the pun).
<<

IF the other driver slams on his brakes, doesn't that adversely influence the
success of the reccomended (turn behind traffic) maneuver?

Jose

(for Email, make the obvious changes in my address)

Barry
August 20th 03, 03:27 AM
> > I hope you tracked the intruder to his destination.
>
> No I didn't. My supervisor and I had a very short discussion about
> doing so and then decided we could prove nothing. Could have
> been bad mode C, no way to prove he was not VMC, the Baron
> never saw him etc etc.

In what situations would you decide to track the traffic? I'm curious
because one very clear night I didn't feel like bothering with Phila.
Approach and just overflew the Philadelphia Class B VFR at 7500 enroute to
Atlantic City. When I called ACY Approach, they told me that Phila. wanted
to talk to me. I called after landing, and Phila. said they showed me below
7000 for part of the time, thus in their Class B without a clearance. I
assured them I was at 7500 the whole time, and agreed to get the Mode C
checked (it was due the next month anyway). Is ATC more likely to pursue a
possible Class B violation than a rogue IMC?

Barry

Chip Jones
August 20th 03, 04:10 AM
"Barry" > wrote in message
...
> > > I hope you tracked the intruder to his destination.
> >
> > No I didn't. My supervisor and I had a very short discussion about
> > doing so and then decided we could prove nothing. Could have
> > been bad mode C, no way to prove he was not VMC, the Baron
> > never saw him etc etc.
>
> In what situations would you decide to track the traffic? I'm curious
> because one very clear night I didn't feel like bothering with Phila.
> Approach and just overflew the Philadelphia Class B VFR at 7500 enroute to
> Atlantic City. When I called ACY Approach, they told me that Phila.
wanted
> to talk to me. I called after landing, and Phila. said they showed me
below
> 7000 for part of the time, thus in their Class B without a clearance. I
> assured them I was at 7500 the whole time, and agreed to get the Mode C
> checked (it was due the next month anyway). Is ATC more likely to pursue
a
> possible Class B violation than a rogue IMC?
>

These days I have to be careful about what I say on the net. Like you point
out, we have the ability to track you. We do track suspected airspace
violators, especially Class B. We don't do the enforcement end so I don't
know what the burden of proof is other than an actual visual sighting etc
but I'd say yes, we are far more likely to pursue a probable Class B
violator than a probable rogue IMC. After all, the Class B (or A or C or D)
is actually there all of the time and always monitored, whereas something
like weather conditions at a given point in time and space is rather
fleeting and subjective.


That "bad Mode C" angle is a factor too. We get guys from time to time
showing up in Class A airspace indicating FL255 or so, VFR. We are usually
pretty sure they are actually down in the weeds with bad Mode C, but we have
no safe way to tell and so treat them as intruders while they display they
are in the flight levels. However, we don't track them unless they appear
to fly hundreds of miles at the same displayed altitude. There is an old
war story that goes around ZTL (and probably other Centers) about a Sun and
Fun weekend where ZTL tracked a VFR aircraft that flew from somewhere north
of the Ohio River all the way down to Florida, indicating FL275. An air
carrier over Alma Georgia got a visual on it and reported it as a P-51, so
ZJX tagged up the target and ATC followed it all the way into Lakeland.
However, allegedly FSDO couldn't ever prove an enforcement because the pilot
claimed that he had been VFR at 17,500 the whole time. Dunno if this story
is fact or fiction. Several ZTL old timers swore they were involved when I
heard it here, but I have since heard a similar story (same theme) about an
Oshkosh-bound P-47 as I was enjoying a cold malted beverage with some Kansas
City Center guys. You know war stories.

Chip, ZTL




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Chip Jones
August 20th 03, 04:19 AM
"Capt. Doug" > wrote in message
...
> >Chip Jones wrote in message > Good point, D. I've actually seen a
talking
> Jackass >work an ATC sector down here, now that you mention it. :-)
>
> Seems to happen everytime I request direct to OKK from JOHNN. :-)

LOL! IIU is about it for directs to Chicagoland from Florida way...

>
> D. (pilots vs. controllers- what a softball game that would be!)
>

Well, at least your monkies could swing a bat. Our Jackasses probably would
have a little trouble with the pitching, too... and it would always be the
pilots's fault. :-)

Chip, ZTL




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Chip Jones
August 20th 03, 04:28 AM
"Snowbird" > wrote in message
om...
> (Scott Lowrey) wrote in message
>...
>
> > BTW, Chip, do you know Don Brown?
>
> Not asking in the biblical sense I hope?
>

Well, this is The South... :-)

Chip, ZTL

[Key "Dueling Banjos"] "Aintree? Haw haw haw! These boys is tryin' to
git to Aintree, Elmer! Y'all done taken a wrong turn, you see. You cain't
git thar frum here... 'lessen you git in that thar River...and it's only the
biggest River in the whole State..."





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Newps
August 20th 03, 05:34 AM
Barry wrote:

> In what situations would you decide to track the traffic? I'm curious
> because one very clear night I didn't feel like bothering with Phila.
> Approach and just overflew the Philadelphia Class B VFR at 7500 enroute to
> Atlantic City. When I called ACY Approach, they told me that Phila. wanted
> to talk to me. I called after landing, and Phila. said they showed me below
> 7000 for part of the time, thus in their Class B without a clearance. I
> assured them I was at 7500 the whole time, and agreed to get the Mode C
> checked (it was due the next month anyway). Is ATC more likely to pursue a
> possible Class B violation than a rogue IMC?

Yes. In most cases ATC does not know an aircraft is illegally IFR
because we don't know what the weather is. I have seen ZLC call a
couple times because they watched traffic for over a thousand miles.
One was a Malibu that busted LAX's class B and landed here at BIL.
Another aircraft busted Denver's class B and came here. Both times we
gave them a phone number supplied by ZLC. Don't know what happened
after that.

Tom S.
August 20th 03, 05:53 AM
"Teacherjh" > wrote in message
...
> >>
> Yet in high speed driving school (i.e., Bondurant) they teach you to
swerve
> BEHIND a car coming across your path. Most drivers will just slam on the
> brakes. In fact, in most every situation the vast majority of drivers will
> just slam on the brakes rather than maneuver out of the way. It's the
> hardest habit the driving instructors have to break (pardon the pun).
> <<
>
> IF the other driver slams on his brakes, doesn't that adversely influence
the
> success of the reccomended (turn behind traffic) maneuver?

Only if he can stop in one car length. In the unlikely event he could, at
worst you sideswipe him(her, more likely :~> ) rather than T-bone them.

Gene Seibel
August 20th 03, 06:07 AM
Works quite well on a 90 degree convergence.


> \. Then it was like a light bulb went on and
> > I realized that the best course of action was to head straight for the
> > point in the sky where he is.
>
> This is the NASCAR version of crash avoidance. Head for where the spinning
> car is now because he probably will have moved by the time you get there.
>
> I guess this will work OK for aircraft provided you are not converging close
> to head-on.

August 20th 03, 09:00 AM
Peter Duniho wrote:

>
> What McNicoll is trying to say in his oh-so-charming way is that "radar
> identified" has a very specific meaning, and the VFR traffic wasn't radar
> identified. Being visible on the radar scope is not in and of itself
> sufficient for being "radar identified".
>

Good points (both about McNicoll and radar identified ;-) Having said that it
seems that the air traffic procedures folks are primarily fooling themselves
(so, what's new? ;-) when they don't consider an unknown secondary target
returning Mode C data to be sufficiently radar identified for merging target
safety action. Good thing TCAS isn't so strict about what it tags.

Steven P. McNicoll
August 20th 03, 12:11 PM
"Peter Duniho" > wrote in message
...
>
> What McNicoll is trying to say in his oh-so-charming way is that "radar
> identified" has a very specific meaning, and the VFR traffic wasn't radar
> identified. Being visible on the radar scope is not in and of itself
> sufficient for being "radar identified".
>

McNicoll did say that, in his usual succinct manner.

Chip Jones
August 20th 03, 12:22 PM
> wrote in message ...
>
>
> I guess had he been above 10,000 you could have used the merging target
provisions of
> the 7110.65?
>

I guess I am not totally following you here, Joe. Besides the "radar
identified" requirement for the traffic, the merging target provisions still
put the onus on the pilot to request vectors for avoidance. I think I still
would have ended up in an alert situation with this pair. Had I known that
these aircraft were going to get so apparently close in the end without a
visual, I would have vectored the Baron early in the interests of air safety
(regardless of what the 7110 dictates) to avoid the alert. Hindsight and
all that. :-)

To further muddy the water, merging target procedures dictate that I issue
traffic information to aircraft whose targets will merge (as in this event)
*unless* the aircraft are separated by more than the appropriate vertical
minima. In the class of airspace that this event occurred in (Class E),
there are no formal vertical separation minima between IFR and VFR aircraft.
Obviously there are several ways to interpret how this procedure does or
does not apply had this scenario occurred above 10,000.

Chip, ZTL




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August 20th 03, 03:08 PM
"Steven P. McNicoll" wrote:

>
> Actually, it is you that is fooling yourself, when you imagine you know
> something about air traffic procedures. The situation described in this
> thread called for a traffic advisory and a safety alert, not merging target
> procedures.

That's the policy created by a bunch of inward thinking idiots at FAA
Headquarters (ATP). That doesn't mean that application of merging target
procedures before it gets to a traffic advisory, then safety alert, whouldn't
be more prudent.

Maule Driver
August 20th 03, 03:52 PM
Heck, you don't even know if his Mode C was correct.

On 2 occassions , in that same general vicinity, my Mode C was showing the
wrong altitude by about 6,000 feet! Why? Transponder problem? I guess so,
but it only happened one other time in one other place and hasn't happened
again.

"Steven P. McNicoll" > wrote in message
k.net...
>
> We don't know that the VFR guy was in IMC, we don't know that he broke any
> rules.

Steven P. McNicoll
August 20th 03, 04:03 PM
"Maule Driver" > wrote in message
om...
>
> Heck, you don't even know if his Mode C was correct.
>

Yes, as I stated in an earlier message.


>
> On 2 occassions , in that same general vicinity, my Mode C was showing the
> wrong altitude by about 6,000 feet! Why? Transponder problem? I guess
so,
> but it only happened one other time in one other place and hasn't happened
> again.
>

A couple of years ago we had a guy flying through GRB approach airspace that
always had bad Mode C. But it was only bad with GRB approach, no other
facility had a problem with it. He had it checked at an avionics shop and
they found nothing wrong.

Stan Gosnell
August 20th 03, 04:59 PM
"John R. Copeland" > wrote in
:

> Yes, my old TCADs used to do that for me in eastern Kansas, too.
> (Or maybe it was in western Missouri, I'm not too sure.)
> I've not noticed it since I upgraded to a 9900BX last year, though.
> ---JRC---

We're getting a few aircraft with the Goodyear system, & I love it. I see
aircraft flying out over the Gulf that I would never see at all if I didn't
see them come up on there. But we sometimes still can't see them, even on
a clear day. It depends a lot on the paint scheme and the position of the
sun. A white and blue helicopter over water is very difficult to see.

--
Regards,

Stan

Ron Natalie
August 20th 03, 05:07 PM
"Stan Gosnell" > wrote in message ...

> We're getting a few aircraft with the Goodyear system, & I love it.

BFG = Goodrich. Wrong tire company.

Ron Natalie
August 20th 03, 07:36 PM
"Roy Smith" > wrote in message ...
> Peter Duniho > wrote:
> > I guess that's a matter of debate. A faulty Mode C readout could cause a
> > TCAS unit to cause an accident, rather than avoid one.
>
> The problem is that we're working with 50 year old technology here.
> The idea that we can't reliably transmit one 24-bit message every 5
> seconds is absurd.
>
TCAS was known to be a crock when it was proposed. It was a political
rather than a technical solution.
..

Newps
August 20th 03, 09:32 PM
Chip Jones wrote:
Had I known that
> these aircraft were going to get so apparently close in the end without a
> visual, I would have vectored the Baron early in the interests of air safety
> (regardless of what the 7110 dictates) to avoid the alert.

That is far and away the better procedure. I have had a few situations
like that and I will never let it get to a safety alert status. The IFR
guy will get vectored. It also saves time.

Stan Gosnell
August 20th 03, 10:29 PM
(Roy Smith) wrote in :

> The problem is that we're working with 50 year old technology here.
> The idea that we can't reliably transmit one 24-bit message every 5
> seconds is absurd.
>
> NASA can transmit images from Neptune better than that.
>

True it's old technology, but we're dealing with a couple of things that
NASA doesn't have to deal with in sending images from Neptune - liability
and bureaucracy. There are several layers of bureaucracy involved with
changing systems within the FAA (not to say there aren't in NASA, either,
but it's more deeply entrenched in the FAA) and nobody dies if the images
from Neptune don't make it or are corrupted. Changing computers within the
FAA requires proving (not showing probability, or proving beyond a
reasonable doubt) that the system will work, and the system, if purchased,
has to go through a bidding process. Thus the computers at the FAA are
generations behind what is on your desktop (as are the computers in the
space shuttle) and the entire system has as much inertia as the entire
earth. I'm amazed that the FAA has responded to GPS as quickly as it has.

--
Regards,

Stan

Stuart King
August 20th 03, 11:00 PM
"Chip Jones" > wrote in message
...
> The other day, I had an air traffic situation I wanted to bounce off of
the
> group. Those of you who don't know me, I'm a Center controller down here
in


--- snip

I feel very strongly that ATC has an obligation to track these rogue idiots.
Controllers may be a passenger/pilots someday too. You dont have to prove
anything, just get them on the phone and advise them that they may wish to
review the rule book before playing in your backyard. It should get their
attention.

Unless they are really stupid, they will likely stop the behavior after
realizing big brother was watching their stunt.

SK

Teacherjh
August 20th 03, 11:05 PM
>>
Thus the computers at the FAA are
generations behind what is on your desktop
<<

And I'm glad of it. If ATC computers crashed as much as my desktop did, there
would be no ATC. And I know ATC computers crash tool

Jose

(for Email, make the obvious changes in my address)

Stan Gosnell
August 21st 03, 03:27 AM
(Teacherjh) wrote in
:

>>>
> Thus the computers at the FAA are
> generations behind what is on your desktop
><<
>
> And I'm glad of it. If ATC computers crashed as much as my desktop
> did, there would be no ATC. And I know ATC computers crash tool

Yeah, but thank God they don't use Windows for an operating system. That
would be truly frightening.

--
Regards,

Stan

Stan Gosnell
August 21st 03, 03:29 AM
"Stuart King" > wrote in
m:

> I feel very strongly that ATC has an obligation to track these rogue
> idiots.

To what purpose? There is no way to prove the flight conditions were IMC.
Just because one pilot reported being in IMC, especially when everyone else
was VMC, does not prove the pilot in question violated anything.

--
Regards,

Stan

Montblack
August 21st 03, 06:11 AM
("Capt. Doug" wrote)

(pilots vs. controllers- what a softball game that would be!)

Man on 3rd base....You are not authorized to cross Home plate. Repeat...hold
short of Home plate!

Person holding short of 1st base, you may now taxi back to the dugout -
you're out.

Ahh, a double play in the making, on a ball hit over the centerfielder's
head.

--
Montblack

G.R. Patterson III
August 21st 03, 02:23 PM
Roy Smith wrote:
>
> NASA can transmit images from Neptune better than that.

I'm sure that I could build a pretty foolproof mode-C if I had NASA's budget.
Doing it for a few hundred dollars is what's difficult.

George Patterson
Brute force has an elegance all its own.

G.R. Patterson III
August 21st 03, 02:29 PM
"Steven P. McNicoll" wrote:
>
> We don't know that this guy was a rogue idiot, there's no evidence that any
> rule was violated.

Sure. So the conversation should go something like "Sir, we tracked you through
our airspace at 6,000'. You might want to have your encoder checked."

George Patterson
Brute force has an elegance all its own.

Maule Driver
August 21st 03, 03:35 PM
"Steven P. McNicoll" > wrote in message
k.net...
>
> > Heck, you don't even know if his Mode C was correct.
> >
> Yes, as I stated in an earlier message.
>
I was just remaking your point. "Piling on" so to speak. Sometimes you
are just too darned succinct.

Maule Driver
August 21st 03, 03:44 PM
"Chip Jones" > wrote in message
...
> > A couple of years ago we had a guy flying through GRB approach airspace
> > always had bad Mode C. But it was only bad with GRB approach, no other
> > facility had a problem with it. He had it checked at an avionics shop
and
> > they found nothing wrong.
> >
> Yep, this kind of Mode C anomoly happens in ZTL airspace too. That's one
> reason we always go with pilot reported altitude over Mode C readout.
>
First time I was called on an inaccurate Mode C by ATL, I took it to the
shop. They said it was OK and serviced it anyway. ATL called me on it
again but it's fine everywhere else, almost....

Anytime I fly from GSO towards CLT, GSO either can't see me, or gets an
incorrect mode C for a short period of time. Can't see why one or the
other. Can't see why there is an anomoly at all. On the other hand, I flew
RDU towards CLT practically every week for 3 or 4 years. GSO never had a
problem seeing me on that route. Just one of those things that awaits
migration to better technology.

Maule Driver
August 21st 03, 03:52 PM
"pilotjww" > wrote in message
...
> Nice thread.
>
> A small nit: I fly a low-wing, and any ATC traffic alert inside of 4-5
miles
> and below my altitude will be hard to see without some maneuvering to
remove
> my airplane's nose or wing from line-of sight. I expect even a high-wing
> will also have at least the problem of traffic under the nose. I get a lot
> of these alerts, where the traffic is a thousand or more below me, often
> unverified, and I find them useless.
>
You might want to think carefully about the potential impact of erroneous
mode C information. It happens. It has happened to me more than once (see
earlier posts). It has caused me to pay attention to those "low and close"
alerts by at least for a moment, pretending that it is at my altitude. At
least it gives you something to scan for. Maybe you'll see that glider
loitering at cloud base.

Chip Jones
August 21st 03, 04:00 PM
"Newps" > wrote in message
news:9VQ0b.210033$Ho3.27525@sccrnsc03...
>
>
> Chip Jones wrote:
> Had I known that
> > these aircraft were going to get so apparently close in the end without
a
> > visual, I would have vectored the Baron early in the interests of air
safety
> > (regardless of what the 7110 dictates) to avoid the alert.
>
> That is far and away the better procedure. I have had a few situations
> like that and I will never let it get to a safety alert status. The IFR
> guy will get vectored. It also saves time.
>

I totally agree, but it requires that you recognize the situation and have
time to deal with it. In my airspace I simply don't have the time to vector
every IFR around potential VFR traffic because I am too busy slinging IFR's
around IFR's or providing other IFR services. The avoidance of the alert to
begin with is indeed better for all concerned IMO, but it is not always
possible because of workload.

Chip, ZTL




----== Posted via Newsfeed.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeed.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
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August 21st 03, 04:59 PM
"Steven P. McNicoll" wrote:

> > wrote in message ...
> >
> > That's the policy created by a bunch of inward thinking idiots at FAA
> > Headquarters (ATP).
> >
>
> You are not in a position to make that judgment..

That's your opinion.

August 21st 03, 05:02 PM
Peter Duniho wrote:

> > wrote in message ...
> > [...] it
> > seems that the air traffic procedures folks are primarily fooling
> themselves
> > (so, what's new? ;-) when they don't consider an unknown secondary target
> > returning Mode C data to be sufficiently radar identified for merging
> target
> > safety action.
>
> Keep in mind that if ATC is not in radio communications with the radar
> target, they have no way to verify the Mode C readout. As such, it should
> be considered unreliable. Since an ATC instruction could include an
> altitude change instead of or in addition to a heading change, the rules
> need to account for that.

That is exactly what a TCAS RA does, and it relies on "unverified" Mode C.
But, a merging target vector should not include an altitude change unless the
controller has the altitude available, and then only as a last resort to an
avoidance vector.

>
>
> My personal opinion is that, generally speaking, the FAA folks who come up
> with ATC procedures do have a clue, and the procedures mostly make sense.
>
> > Good thing TCAS isn't so strict about what it tags.
>
> I guess that's a matter of debate. A faulty Mode C readout could cause a
> TCAS unit to cause an accident, rather than avoid one.

Well, so far it has only prevented accidents. Had it been used properly on the
Swiss border, a lot of folks would still be alive today..

August 21st 03, 05:06 PM
"Steven P. McNicoll" wrote:

> "Newps" > wrote in message
> news:N3h0b.192923$Ho3.26290@sccrnsc03...
> >
> > That was cool. I would tag up the "VFR" pilot and run him thru FSDO.
> > You have proof he was IMC.
> >
>
> You'd have proof that he was in IMC only if he had collided with the guy at
> 7000 in IMC.

How would that provide proof that the collision took place in IMC?

Roy Smith
August 21st 03, 05:21 PM
> wrote:
> "unverified" Mode C.

When a Mode C readout is wrong, where is the problem? Is the encoder
producing bad data? Is the data path between the encoder and the
xponder corrupting the data? Is the xpdonder corrupting the data? Is
the RF pulse from the xponder being corrupted? Is the receiver not
decoding it right?

Dr. Anthony J. Lomenzo
August 21st 03, 05:59 PM
Montblack wrote:
>
> ("Capt. Doug" wrote)
>
> (pilots vs. controllers- what a softball game that would be!)
>
> Man on 3rd base....You are not authorized to cross Home plate. Repeat...hold
> short of Home plate!
>
> Person holding short of 1st base, you may now taxi back to the dugout -
> you're out.
>
> Ahh, a double play in the making, on a ball hit over the centerfielder's
> head.
>
> --
> Montblack



Dare I ask the classic A&C bit, to wit, 'who' is on first...'what' is on
second....and 'I don't know' is on third?

Doc Tony
;-)

[suddenly...]

George H. "Let's get serious [!] here, Doc! What we need are 'team'
names! In effect, what is the 'team' name for the the ATC controllers
and what is the 'team' name for the pilots? Something 'catchy' perhaps!"

Chip: "Well, how's this: 'Air Wizards' for the ATC folks [pauses...] and
'TINJOCKEYS" for the pilots?"

X: [JD/LL.B. type from one of the av groups!] "Objection! The name
'tinjockeys' is clearly an inequitable visual analogy when the other
team bears the otherwise superlative name of alleged 'air wizards'!"

Y: [quickly grabs the Black Robe from the chair nearest the KB and
assumes an ad hoc judicial posture.... !] "Objection over-ruled!"

X: "Exception!"

Y: "Noted!"

Doc Tony: "How about we take the acronym approach! What say ye to the
"DAMNED" [Descend And Maintain Normal Equated Distance] for the ATC
folks and the "CAVULARIOS" for the pilots?"

George H. "Nahhhh. Simply "AIRS" for 'us' that fly versus "SEATS" for
'them' that sits!"

Chip: [and duly noting George's comment.....] "Well, as an alternative,
what say to the "SCOPES" versus the "GROPES" !"

;-)


Ohhh, what harm.

[from the other thread...and STILL at it...throat well coarse now! ]

Jim Fisher: "SEND DOWN 50' OF ROPE.....fer cryin' out loud!"

great flick, that one!

[but to my utter surprise...talking about flicks...]

Montblack: [doing the commanding officer to Detective 'Popeye' Doyle
bit...] "You know your hunches have been wrong before, Doc, or have you
forgotten about that?"

;-)

Jim Fisher: [the man loves those old flicks! Reverts and gets very
serious....indeed angry!!] "Six weeks my partner and I worked this case
and WHO do we come up with...PETE DUNIHO fer cripes sake...now you
gotta' give us that warrant!" [*later for 'Joel Weinstock'..the actual
script line]

Peter Duniho
August 21st 03, 06:13 PM
> wrote in message ...
> That is exactly what a TCAS RA does, and it relies on "unverified" Mode C.

As I mentioned, this is not as safe as people (i.e. you) would like to
think.

> But, a merging target vector should not include an altitude change unless
the
> controller has the altitude available, and then only as a last resort to
an
> avoidance vector.

Your original question was regarding why vectoring is not part of the ATC
standard procedures for dealing with a VFR target. I'm simply answering
that. You are correct that one could limit the vector to no altitude
changes. But that's simply not how the handbook is written.

As far as I know, the language used in the controller's handbook allows
altitude changes any time a controller is supposed to vector an airplane.
It would be a significant change, and would add even more complexity to the
handbook, to call out this particular case as a situation where the
controller is permitted to providing heading guidance but not altitude.

I'm not interested in a debate, and I don't see why you seem to be itching
for one. If you really want to debate the matter, call up the FAA and
discuss it with them. They wrote the controller's handbook, not I.

> > I guess that's a matter of debate. A faulty Mode C readout could cause
a
> > TCAS unit to cause an accident, rather than avoid one.
>
> Well, so far it has only prevented accidents. Had it been used properly
on the
> Swiss border, a lot of folks would still be alive today..

I have a friend who would never wear a seatbelt, because she had a relative
who had been thrown from a car in an accident and walked away unscathed.
The logic she was using is similar to your use of a single example to
justify the use of TCAS.

I assure you that if controllers started using unverified Mode C returns to
provide altitude changes for traffic avoidance on a regular basis,
eventually someone would wind up at the same altitude of traffic that ATC
thought they were moving them away from.

The main reason that TCAS doesn't cause accidents today is that it's used in
a way that is unlikely to cause accidents. Airplanes that are in IMC are
being positively controlled by ATC, and the TCAS should only provide a
warning when ATC has made an egregious error. That doesn't happen very
often. Furthermore, the airplanes involved are both under radar control, so
even though the TCAS doesn't know it, the Mode C *has* been verified.
Airplanes that are in VMC, whether under positive control by ATC or not,
have the ability to use the TCAS to help them *spot traffic*, rather than
just blindly trust the TCAS to tell them what to do. The pilots can then
make a course adjustment as appropriate, based on *what they see*.

The controller rules are not written to allow things that are "mostly safe".
They are written to try to make sure that the controller's actions are 100%
safe in ALL situations. In cases where the controller is unable to know for
certain that they are able to separate traffic, the controller is simply not
allowed to attempt it. As such, an unconfirmed Mode C readout is simply not
a piece of information that a controller is allowed to use for positive
control of another aircraft.

It's sort of the Hippocratic Oath of air traffic control. Whatever else
they do, a controller should not make the situation worse.

Pete

David Brooks
August 21st 03, 06:15 PM
"Maule Driver" > wrote in message
om...
>
> "pilotjww" > wrote in message
> ...
> > Nice thread.
> >
> > A small nit: I fly a low-wing, and any ATC traffic alert inside of 4-5
> miles
> > and below my altitude will be hard to see without some maneuvering to
> remove
> > my airplane's nose or wing from line-of sight. I expect even a high-wing
> > will also have at least the problem of traffic under the nose. I get a
lot
> > of these alerts, where the traffic is a thousand or more below me, often
> > unverified, and I find them useless.
> >
> You might want to think carefully about the potential impact of erroneous
> mode C information. It happens. It has happened to me more than once
(see
> earlier posts). It has caused me to pay attention to those "low and
close"
> alerts by at least for a moment, pretending that it is at my altitude. At
> least it gives you something to scan for. Maybe you'll see that glider
> loitering at cloud base.


If ATC has you verified and another target unverified indicating a safely
separated altitude, is it SOP to call traffic just in case? Will the
controller make use of a previous report ("he's wa-a-ay below me") in
deciding whether to do so?

-- David Brooks

Peter Duniho
August 21st 03, 06:15 PM
> wrote in message ...
> > You'd have proof that he was in IMC only if he had collided with the guy
at
> > 7000 in IMC.
>
> How would that provide proof that the collision took place in IMC?

Are you asking how the collision occuring in IMC would prove that the
collision took place in IMC?

Sounds like a "if a tree falls in the forest with no one near enough to hear
it" sort of question...

Newps
August 21st 03, 09:02 PM
Chip Jones wrote:

>
> I totally agree, but it requires that you recognize the situation and have
> time to deal with it. In my airspace I simply don't have the time to vector
> every IFR around potential VFR traffic because I am too busy slinging IFR's
> around IFR's or providing other IFR services. The avoidance of the alert to
> begin with is indeed better for all concerned IMO, but it is not always
> possible because of workload.

Lucky for me I've got nothing but time.

Newps
August 21st 03, 09:04 PM
The problem is you spent $200 on an encoder 10 years ago and expect it
to work for a lifetime. You very rarely if ever see a bad mode C on an
airliner.

Roy Smith wrote:

> > wrote:
>
>>"unverified" Mode C.
>
>
> When a Mode C readout is wrong, where is the problem? Is the encoder
> producing bad data? Is the data path between the encoder and the
> xponder corrupting the data? Is the xpdonder corrupting the data? Is
> the RF pulse from the xponder being corrupted? Is the receiver not
> decoding it right?

Newps
August 21st 03, 09:11 PM
Peter Duniho wrote:


> As far as I know, the language used in the controller's handbook allows
> altitude changes any time a controller is supposed to vector an airplane.
> It would be a significant change, and would add even more complexity to the
> handbook, to call out this particular case as a situation where the
> controller is permitted to providing heading guidance but not altitude.

A controller owns a chunk of airspace. As long as I meet the separation
standards I can do whatever I need to with you.



> The main reason that TCAS doesn't cause accidents today is that it's used in
> a way that is unlikely to cause accidents. Airplanes that are in IMC are
> being positively controlled by ATC, and the TCAS should only provide a
> warning when ATC has made an egregious error. That doesn't happen very
> often. Furthermore, the airplanes involved are both under radar control, so
> even though the TCAS doesn't know it, the Mode C *has* been verified.
> Airplanes that are in VMC, whether under positive control by ATC or not,
> have the ability to use the TCAS to help them *spot traffic*, rather than
> just blindly trust the TCAS to tell them what to do. The pilots can then
> make a course adjustment as appropriate, based on *what they see*.

TCAS is most useful in class D type tower situations. These are where
you are most likely to have the spam cans flying around with unverified
mode C. If the TCAS gives an RA the airliner must take the action
suggested. Places like Orange County and Pontiac come to mind. Lots
and lots of VFR targets

Steven P. McNicoll
August 22nd 03, 12:15 AM
> wrote in message ...
>
> That's your opinion.
>

That's my observation.

Steven P. McNicoll
August 22nd 03, 12:18 AM
"Newps" > wrote in message
news:cI91b.218085$Ho3.28456@sccrnsc03...
>
> A controller owns a chunk of airspace. As long as I meet the separation
> standards I can do whatever I need to with you.
>

The controller can do only what is consistent with FAAO 7110.65.

Steven P. McNicoll
August 22nd 03, 12:19 AM
> wrote in message ...
>
> How would that provide proof that the collision took place in IMC?
>

Because the guy at 7000 stated he was in IMC.

August 22nd 03, 12:41 AM
Peter Duniho wrote:

> > wrote in message ...
> > That is exactly what a TCAS RA does, and it relies on "unverified" Mode C.
>
> As I mentioned, this is not as safe as people (i.e. you) would like to
> think.

It has already saved a few friends of mine, in one case IFR vs. IFR in the
flight levels. Perhaps it is not as safe as it could be, but it's a lot safer
than not having it at all. Same goes for GPWS and EGPWS.

Dan Luke
August 22nd 03, 12:42 AM
"Maule Driver" wrote:
> > Yep, this kind of Mode C anomoly happens in ZTL airspace too.
That's one
> > reason we always go with pilot reported altitude over Mode C
readout.
> >
> First time I was called on an inaccurate Mode C by ATL, I took it to
the
> shop. They said it was OK and serviced it anyway. ATL called me on
it
> again but it's fine everywhere else, almost....

I used to have this trouble westbound through Gulfport's airspace all
the time. It never happened anywhere else and two trips to the shop
didn't help.When I replaced the xponder and encoder with more modern
stuff, the problem disappeared.
--
Dan
C172RG at BFM

G.R. Patterson III
August 22nd 03, 01:21 AM
Newps wrote:
>
> The problem is you spent $200 on an encoder 10 years ago and expect it
> to work for a lifetime. You very rarely if ever see a bad mode C on an
> airliner.

The implication is that airliners use better transponders and/or associated
equipment. What are they using?

George Patterson
Brute force has an elegance all its own.

Roy Smith
August 22nd 03, 01:30 AM
Newps > wrote:

> If the TCAS gives an RA the airliner must take the action
> suggested.

Do TCAS RA's take terrain into account?

Peter Duniho
August 22nd 03, 02:12 AM
> wrote in message ...
> It has already saved a few friends of mine, in one case IFR vs. IFR in the
> flight levels. Perhaps it is not as safe as it could be, but it's a lot
safer
> than not having it at all.

Again, you are mistaking a technology that helps increase overall safety
statistics with one that can be counted on in every situation to improve
safety.

There's a difference.

Bob Noel
August 22nd 03, 04:05 AM
In article >,
Roy Smith > wrote:

> > If the TCAS gives an RA the airliner must take the action
> > suggested.
>
> Do TCAS RA's take terrain into account?

TCAS units do not contain terrain databases.

--
Bob Noel

Newps
August 22nd 03, 04:13 AM
Roy Smith wrote:
> Newps > wrote:
>
>
>>If the TCAS gives an RA the airliner must take the action
>>suggested.
>
>
> Do TCAS RA's take terrain into account?

Yes, the airplane knows how high it is. It will not drive it self into
the ground.

Snowbird
August 22nd 03, 01:01 PM
Newps > wrote in message news:<dTf1b.167931$cF.58574@rwcrnsc53>...
> Roy Smith wrote:
> > Newps > wrote:
> >
> >
> >>If the TCAS gives an RA the airliner must take the action
> >>suggested.
> >
> >
> > Do TCAS RA's take terrain into account?
>
> Yes, the airplane knows how high it is. It will not drive it self into
> the ground.

Knowing how high it is, is only part of what's needed -- does it
know where it is, and how high the terrain is nearby?

Cheers,
Sydney

Chip Jones
August 22nd 03, 03:34 PM
"G.R. Patterson III" > wrote in message
...
>
>
> Newps wrote:
> >
> > The problem is you spent $200 on an encoder 10 years ago and expect it
> > to work for a lifetime. You very rarely if ever see a bad mode C on an
> > airliner.
>
> The implication is that airliners use better transponders and/or
associated
> equipment. What are they using?

Better maintenance maybe?

Chip, ZTL

Chip Jones
August 22nd 03, 03:34 PM
"Michael 182" > wrote in message
news:ATr0b.152537$Oz4.42083@rwcrnsc54...
>
[snipped]
>
> If I wanted to commend his work to his supervisor, how would I do so? He
did
> a great job - every handoff was accompanied by "123.45, Great job today!
> Thanks"
>

If you wanted to coomend his work, you'd have to dial the main commercial
line into the facility with your kudos. Even then it is unlikely the actual
controller would hear of it (unless it was BAD service, and then they'd
track it down). I'd say the best way to commend his work would be this: On
one of those days when you are dealing with an ATC Jackass somewhere in the
system, just remember that good controllers like the ZME guy exist too.

Chip, ZTL

Chip Jones
August 22nd 03, 03:34 PM
"T-Boy" > wrote in message
. nz...
> In article >,
> says...
>
> PS: did you catch up with the "VFR" :) - traffic.
>

Nope, we watched him tool along towards North Carolina and lost him in the
Blue Ridge near Macon County 1A5 (where he appeared to land).

Chip, ZTL

Maule Driver
August 22nd 03, 04:22 PM
"Steven P. McNicoll" > wrote in message
ink.net...
>
> > I was just remaking your point. "Piling on" so to speak. Sometimes
you
> > are just too darned succinct.
> >
>
> I see no reason to use twenty words if I can say it in ten.
>

I know.

Everett M. Greene
August 22nd 03, 06:44 PM
"Steven P. McNicoll" > writes:
> > wrote
> >
> > How would that provide proof that the collision took place in IMC?
>
> Because the guy at 7000 stated he was in IMC.

That's not proof, that's a statement. The other plane was
"saying" it's VMC.

Newps
August 22nd 03, 08:36 PM
Once below a certain agl altitude the TCAS will not give and RA but only
a TA.

Roy Smith wrote:
> I asked:
>
>>>Do TCAS RA's take terrain into account?
>
>
> Newps > wrote:
>
>>Yes, the airplane knows how high it is. It will not drive it self into
>>the ground.
>
>
> Bob Noel > wrote:
>
>>TCAS units do not contain terrain databases.
>
>
> I'm having a hard time making these two responses jive :-)

Ron Natalie
August 22nd 03, 08:41 PM
"Newps" > wrote in message news:ihu1b.227105$Ho3.29390@sccrnsc03...
> Once below a certain agl altitude the TCAS will not give and RA but only
> a TA.
>
It's needs to be hooked to the radar altimiter in addition to the pressuer alt. from the
encoder/air data computer?

Newps
August 22nd 03, 08:48 PM
Snowbird wrote:

> Newps > wrote in message news:<dTf1b.167931$cF.58574@rwcrnsc53>...
>
>>Roy Smith wrote:
>>
>>>Newps > wrote:
>>>
>>>
>>>
>>>>If the TCAS gives an RA the airliner must take the action
>>>>suggested.
>>>
>>>
>>>Do TCAS RA's take terrain into account?
>>
>>Yes, the airplane knows how high it is. It will not drive it self into
>>the ground.
>
>
> Knowing how high it is, is only part of what's needed -- does it
> know where it is, and how high the terrain is nearby?

Doesn't need to know where it is. Only how far above the ground it is
or will be in a few seconds. The TCAS will only tell you to go either
up or down, not right or left.

Bob Noel
August 22nd 03, 11:13 PM
In article >, Roy Smith
> wrote:

> I asked:
> >> Do TCAS RA's take terrain into account?
>
> Newps > wrote:
> > Yes, the airplane knows how high it is. It will not drive it self into
> > the ground.
>
> Bob Noel > wrote:
> > TCAS units do not contain terrain databases.
>
> I'm having a hard time making these two responses jive :-)

I haven't had an opportunity to check my TCAS sources. But
I seem to remember the TCAS II unit having some interface
with the Radar Altimeter. Also, I'm pretty sure that a GPWS
(or TAWS) warning/alert/whateveritiscalled takes priority over
an RA.

Note that a radar altimeter isn't normally used above 2500' agl.

does that help?

--
Bob Noel

Steven P. McNicoll
August 23rd 03, 10:50 AM
"Everett M. Greene" > wrote in message
...
>
> That's not proof, that's a statement. The other plane was
> "saying" it's VMC.
>

A pilot's report of his flight conditions is taken as fact.

Steven P. McNicoll
August 23rd 03, 10:51 AM
"Newps" > wrote in message
news:ihu1b.227105$Ho3.29390@sccrnsc03...
>
> Once below a certain agl altitude the TCAS will not give and RA but only
> a TA.
>

How does the TCAS know the AGL altitude?

Richard Kaplan
August 23rd 03, 02:54 PM
I think the logic of what you say is correct but in the heat of things but
is not intuitive to a pilot who has not been taught this and had the
opportunity to think it out on the ground. The instinctive reaction of a
pilot otherwise is to turn left when he is told traffic is on the right,
even though futher analysis under calm conditions leads to an alternate
conclusion as you noted.

--
Richard Kaplan, CFII

www.flyimc.com

Everett M. Greene
August 23rd 03, 05:15 PM
"Steven P. McNicoll" > writes:
> "Everett M. Greene" > wrote:
> >
> > That's not proof, that's a statement. The other plane was
> > "saying" it's VMC.
>
> A pilot's report of his flight conditions is taken as fact.

Procedurally, you are correct -- if the pilot says he's IMC,
ATC handles him accordingly. However, his statement isn't a
"fact" in the legal sense in that it's uncorraborated and in
the situation being discussed, another pilot is "saying" it's
VMC by his actions. Which of the two "facts" is correct?

Steven P. McNicoll
August 23rd 03, 10:59 PM
"Everett M. Greene" > wrote in message
...
>
> Procedurally, you are correct -- if the pilot says he's IMC,
> ATC handles him accordingly. However, his statement isn't a
> "fact" in the legal sense in that it's uncorraborated and in
> the situation being discussed, another pilot is "saying" it's
> VMC by his actions. Which of the two "facts" is correct?
>

The pilot not communicating with ATC isn't saying anything.

August 24th 03, 02:05 AM
Peter Duniho wrote:

> > wrote in message ...
> > It has already saved a few friends of mine, in one case IFR vs. IFR in the
> > flight levels. Perhaps it is not as safe as it could be, but it's a lot
> safer
> > than not having it at all.
>
> Again, you are mistaking a technology that helps increase overall safety
> statistics with one that can be counted on in every situation to improve
> safety.
>
> There's a difference.

Yes, the former is achievable; the latter is not.

Peter Duniho
August 24th 03, 06:57 AM
> wrote in message ...
> Yes, the former is achievable; the latter is not.

Nevertheless, the guidelines are written to be as close to possible to the
latter, not the former.

Everett M. Greene
August 24th 03, 07:53 PM
"Steven P. McNicoll" > writes:
> "Everett M. Greene" > wrote
> >
> > Procedurally, you are correct -- if the pilot says he's IMC,
> > ATC handles him accordingly. However, his statement isn't a
> > "fact" in the legal sense in that it's uncorraborated and in
> > the situation being discussed, another pilot is "saying" it's
> > VMC by his actions. Which of the two "facts" is correct?
>
> The pilot not communicating with ATC isn't saying anything.

Actions speak louder than (as loud as) words. If the other
pilot believes it to be VMC, he doesn't have to talk to ATC
and can pass through any altitude desired to or from a VFR
altitude.

Steven P. McNicoll
August 24th 03, 10:14 PM
"Everett M. Greene" > wrote in message
...
>
> Actions speak louder than (as loud as) words. If the other
> pilot believes it to be VMC, he doesn't have to talk to ATC
> and can pass through any altitude desired to or from a VFR
> altitude.
>

There's no evidence that the VFR pilot was not in VMC at all times.

Ron Natalie
August 25th 03, 03:55 PM
"Bob Noel" > wrote in message news:ihatessppaamm-
>
> I haven't had an opportunity to check my TCAS sources. But
> I seem to remember the TCAS II unit having some interface
> with the Radar Altimeter. Also, I'm pretty sure that a GPWS
> (or TAWS) warning/alert/whateveritiscalled takes priority over
> an RA.
>
> Note that a radar altimeter isn't normally used above 2500' agl.
>
I found some TCAS II block diagrams and it is connected to both
the pressure alt and the radar altimeter. There appears to be
a shift in the RA behavior at 1700' AGL which would jive with your
2500' threshold

Snowbird
August 27th 03, 08:08 PM
"Chip Jones" > wrote in message >...
> Part of this "voice" thing for me is always sound like I'm in complete
> control (even when I am not). I did try to be clear and concise and I did
> emphasize the control suggestion in this scenario but I did not really
> change my tone of voice to what I think of as "urgent". I am reevaluating
> my technique here- your suggestion certainly has some merit.

Chip, JMO, but I don't think your technique needs reevaluation.

Long ago in days gone by when the kids walked 2 miles to school
through 3 ft tall drifts uphill in both directions, I was an
EMT in a major hospital emergency room. I learned two things
PDQ:
1) in an emergency, if I wanted anyone to do what I said, I
had to cultivate a calm, DEEP tone of voice (as a young
woman, the deep part was more of an issue for me)
2) the experienced hands all knew this and would chide me
"calm down, relax" if I didn't make a point of it, which
was embarassing and all that

I believe there have actually been some studies done which
show that in a crisis situation, humans respond best to a calm
authoritative voice.

FWIW
Sydney

Tina Marie
August 29th 03, 05:27 PM
In article >,
Snowbird > wrote:
>Doesn't this sound like a good title for a thriller?
>
>"The Haunted Controller"

While I don't know of any that actually involve ghosts, the concept of
"Controller spends the rest of his life thinking about people who
died because of something he thinks he did/didn't do" has been done,
well, to death.

"Airport" had one, "Turbulance" had one, and I'm sure there are lots
more...

Tina Marie
--
Life is like an analogy. http://www.tripacerdriver.com

Mitchell Gossman
August 30th 03, 02:20 AM
Do controllers have a corollary of the PIC command authority, i.e. do
what's right to save lives even if it means breaking 7110? Such as
when you issued vectors to your beer-offering pilot in distress on
top?

Mitch Gossman

"Chip Jones" > wrote in message >...
> > wrote in message ...
> >
> >
> > I guess had he been above 10,000 you could have used the merging target
> provisions of
> > the 7110.65?
> >
>
> I guess I am not totally following you here, Joe. Besides the "radar
> identified" requirement for the traffic, the merging target provisions still
> put the onus on the pilot to request vectors for avoidance. I think I still
> would have ended up in an alert situation with this pair. Had I known that
> these aircraft were going to get so apparently close in the end without a
> visual, I would have vectored the Baron early in the interests of air safety
> (regardless of what the 7110 dictates) to avoid the alert. Hindsight and
> all that. :-)
>
> To further muddy the water, merging target procedures dictate that I issue
> traffic information to aircraft whose targets will merge (as in this event)
> *unless* the aircraft are separated by more than the appropriate vertical
> minima. In the class of airspace that this event occurred in (Class E),
> there are no formal vertical separation minima between IFR and VFR aircraft.
> Obviously there are several ways to interpret how this procedure does or
> does not apply had this scenario occurred above 10,000.
>
> Chip, ZTL
>
>
>
>
> ----== Posted via Newsfeed.Com - Unlimited-Uncensored-Secure Usenet News==----
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Steven P. McNicoll
August 30th 03, 04:02 AM
"Mitchell Gossman" > wrote in message
om...
>
> Do controllers have a corollary of the PIC command authority, i.e. do
> what's right to save lives even if it means breaking 7110? Such as
> when you issued vectors to your beer-offering pilot in distress on
> top?
>

Yes, see subparagraph c. below:


FAA Order 7110.65N Air Traffic Control

Chapter 2. General Control

Section 1. General

2-1-1. ATC SERVICE

The primary purpose of the ATC system is to prevent a collision
between aircraft operating in the system and to organize and expedite the
flow of traffic. In addition to its primary function, the ATC system has the
capability to provide (with certain limitations) additional services. The
ability to provide additional services is limited by many factors, such as
the volume of traffic, frequency congestion, quality of radar, controller
workload, higher priority duties, and the pure physical inability to scan
and detect those situations that fall in this category. It is recognized
that these services cannot be provided in cases in which the provision of
services is precluded by the above factors. Consistent with the
aforementioned conditions, controllers shall provide additional service
procedures to the extent permitted by higher priority duties and other
circumstances. The provision of additional services is not optional on the
part of the controller, but rather is required when the work situation
permits. Provide air traffic control service in accordance with the
procedures and minima in this order except when:

a. A deviation is necessary to conform with ICAO Documents, National
Rules of the Air, or special agreements where the U.S. provides air traffic
control service in airspace outside the U.S. and its possessions or:

NOTE-
Pilots are required to abide by CFR's or other applicable
regulations
regardless of the application of any procedure or minima in this order.

b. Other procedures/minima are prescribed in a letter of agreement,
FAA directive, or a military document, or:

NOTE-
These procedures may include altitude reservations, air refueling,
fighter interceptor operations, law enforcement, etc.

REFERENCE-
FAAO 7110.65, Procedural Letters of Agreement, Para 1-1-8.

c. A deviation is necessary to assist an aircraft when an emergency
has been declared.

REFERENCE-
FAAO 7110.65, Safety Alert, Para 2-1-6.
FAAO 7110.65, Emergencies, Chapter 10.
FAAO 7110.65, Merging Target Procedures, Para 5-1-8.

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