Anti-collision mechanism

[Ramapriya]

Does this get activated only when there's an aircraft in the dangerous
vicinity or will it also trigger if the aircraft is hurtling towards
some terrain such as a hill?

And does every aircraft have this system these days, regardless of
size?

Ramapriya

[Bob Moore]

"Ramapriya" wrote

> Does this get activated only when there's an aircraft in the dangerous
> vicinity or will it also trigger if the aircraft is hurtling towards
> some terrain such as a hill?

In my generation of aircraft, (B-727) they are two different systems.
First came the GPWS (Ground Proximity Warning System) and then some
time later came the TCAS (Traffic Alert and Collision Advoidance System).

> And does every aircraft have this system these days, regardless of
> size?

No, only passenger jets are required to have them.

Bob Moore

[Larry Dighera]

On Sat, 01 Jan 2005 15:25:18 GMT, Bob Moore >
wrote in >::

>"Ramapriya" wrote
[...]
>> And does every aircraft have this system these days, regardless of
>> size?
>
>No, only passenger jets are required to have them.

The military is starting to equip some of their aircraft with TCAS
also:
http://groups-beta.google.com/group/rec.aviation.military/browse_frm/thread/e9f32da816474131/e847fdd9d99f88a5?q=tcas+military+author:larry+auth or:dighera&_done=%2Fgroups%3Fas_q%3Dtcas+military%26safe%3Dim ages%26as_uauthors%3Dlarry+dighera%26lr%3D%26hl%3D en%26&_doneTitle=Back+to+Search&&d#e847fdd9d99f88a5

[Andrew Sarangan]

Then there is the anticollision light system (blinking tail light or
strobes).


Bob Moore > wrote in
. 122:

> "Ramapriya" wrote
>
>> Does this get activated only when there's an aircraft in the dangerous
>> vicinity or will it also trigger if the aircraft is hurtling towards
>> some terrain such as a hill?
>
> In my generation of aircraft, (B-727) they are two different systems.
> First came the GPWS (Ground Proximity Warning System) and then some
> time later came the TCAS (Traffic Alert and Collision Advoidance System).
>
>> And does every aircraft have this system these days, regardless of
>> size?
>
> No, only passenger jets are required to have them.
>
> Bob Moore

[C J Campbell]

"Ramapriya" > wrote in message
oups.com...
> Does this get activated only when there's an aircraft in the dangerous
> vicinity or will it also trigger if the aircraft is hurtling towards
> some terrain such as a hill?
>

You are really talking about two types of systems here. One is for traffic
avoidance, which projects the path of yours and other aircraft and lets you
know if there is a conflict. Some of these systems depict all the aircraft
in the area, along with their direction and altitude, on a moving map.

Terrain avoidance systems warn you of terrain.

> And does every aircraft have this system these days, regardless of
> size?
>

No. The systems are very expensive and are typically not found on small
aircraft. However, more of the newer planes do have these systems,
especially the newer glass cockpit displays. There are even some handheld
devices that perform somewhat the same function with more or less
effectiveness. None of them substitute in small planes for a good set of
eyes looking out of the cockpit.

For one thing, traffic avoidance systems usually depend on other aircraft
having transponders, but some people don't turn their transponders on and
some aircraft have no transponders at all.

[Matt Barrow]

"Bob Moore" > wrote in message
. 122...
> "Ramapriya" wrote
>
> > Does this get activated only when there's an aircraft in the dangerous
> > vicinity or will it also trigger if the aircraft is hurtling towards
> > some terrain such as a hill?
>
> In my generation of aircraft, (B-727) they are two different systems.
> First came the GPWS (Ground Proximity Warning System) and then some
> time later came the TCAS (Traffic Alert and Collision Advoidance System).

And now TAWS is surplanting GPWS and EGPWS.

http://www.sandel.com/sandel/files/TAWS_Final_Rule.pdf
http://www.sandel.com/taws_technotes_primer.htm

>
> > And does every aircraft have this system these days, regardless of
> > size?
>
> No, only passenger jets are required to have them.

But TAWS and TCAS are now available for smaller GA aircraft.

Shortly, they will be required for turbine aircraft with seven (?) or more
seats.

[Garner Miller]

In article >, Bob
Moore > wrote:

> > And does every aircraft have this system these days, regardless of
> > size?
>
> No, only passenger jets are required to have them.

Well, airline passenger turboprops, too. :-)

--
Garner R. Miller
ATP/CFII/MEI
Clifton Park, NY =USA=

[Don Hammer]

>
>No, only passenger jets are required to have them.
>
>Bob Moore

Not quite true. All turbine aircraft with over 6 passenger seats are
now required to have a TAWS and a CAS system and virtually all
corporate operators have installed them years ago. I installed TCAS II
in my company Gulfstream before it was even mandated by the airlines.

I haven't seen a corporate jet delivered in the last 20 or so years
that didn't have cockpit equipment much better than any airliner.
Typically, all corporate jets get EGPWS and TCAS with HUD and EVS on
the larger ones.

The ones that come kicking and screaming into the 21st century are the
airlines and charter operators. Because of cost, they won't install
any equipment that is not required for regulation or the route.

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[george]

I'm a fan of the Mark1 eyeball. It's generally a much undervalued
detector

[Don Hammer]

Bob,
To learn more -
http://www.honeywelltcas.com/
http://www.egpws.com/

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[Don Hammer]

On 1 Jan 2005 15:17:49 -0800, "george" > wrotD:

>I'm a fan of the Mark1 eyeball. It's generally a much undervalued
>detector


Take a look at http://www.gulfstream.com/product_enhancement/evs/ and
tell me the bare eye is better. You'll need high speed for the video.

Also, since TCAS has been mandated, there has been only one mid-air
with equipped aircraft and it was because one crew ignored the
warning. (UPS and Aeroflot in Switzerland)

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[Peter Duniho]

"Don Hammer" > wrote in message
...
> Also, since TCAS has been mandated, there has been only one mid-air
> with equipped aircraft

How many mid-air collisions of commercial airliners not equipped have there
been? Before the mandate, of course (I assume after the mandate there
haven't been any commercial airliners not equipped, right?).

Pete

[James Robinson]

Don Hammer wrote:
>
> Also, since TCAS has been mandated, there has been only one mid-air
> with equipped aircraft and it was because one crew ignored the
> warning. (UPS and Aeroflot in Switzerland)

DHL and Bashkirian Airlines, actually.

[Don Hammer]

On Sun, 02 Jan 2005 00:18:38 GMT, James Robinson >
wrotD:

>DHL and Bashkirian Airlines, actually

Right you are - gray matter isn't what it used to be.


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[Bob Noel]

In article >,
Larry Dighera > wrote:

> >> And does every aircraft have this system these days, regardless of
> >> size?
> >
> >No, only passenger jets are required to have them.
>
> The military is starting to equip some of their aircraft with TCAS
> also:

The USAF started equipping aircraft with TCAS more than 5 years ago.
Heck, the C-141s equipped with TCAS are already being retired.

--
Bob Noel
looking for a sig the lawyers will like

[Don Hammer]

On Sat, 1 Jan 2005 16:04:42 -0800, "Peter Duniho"
>How many mid-air collisions of commercial airliners not equipped have there
>been? Before the mandate, of course (I assume after the mandate there
>haven't been any commercial airliners not equipped, right?).
>
>Pete
>

Don't know the numbers for sure, but it used to be a fairly frequent
occurrence for airliners to hit small aircraft. Of course the press
always got it the other way around. That's why we have to have
transponders is certain airspace in small aircraft. The TCAS will see
our Mode C.

Seems like everything that ends up being mandated is because something
happened. If memory serves it was a Connie and DC-6 in the 50's that
ran in to each other over the Grand Canyon that caused the ATC system
as we know it. AA in Cali Columbia is why we have EGPWS. ValuJet is
why airliners have to have fire suppression in the baggage hold etc.

All commercial airliners are required to have TCAS II with Mode S
transponders; Commuters (up to 30 seats, I think) TCAS I



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[Larry Dighera]

On Sat, 01 Jan 2005 19:34:03 -0600, Don Hammer > wrote in
>::

>... it used to be a fairly frequent
>occurrence for airliners to hit small aircraft. Of course the press
>always got it the other way around. That's why we have to have
>transponders is certain airspace in small aircraft.

Here's the MAC that lead to mandatory TCAS:
http://www.ntsb.gov/NTSB/brief.asp?ev_id=20001213X34444&key=2

[[email protected]]

On Sat, 1 Jan 2005 10:52:11 -0700, "Matt Barrow" >
wrote:


>And now TAWS is surplanting GPWS and EGPWS.
>
>http://www.sandel.com/sandel/files/TAWS_Final_Rule.pdf
>http://www.sandel.com/taws_technotes_primer.htm
>

EGPWS is a trade name (Honeywell product) TAWS is an "official" FAA
acronym.

That would be why you will find the term TAWS widely referred to, and
EGPWS only pertaining to Honeywell systems.

EGPWS is a TAWS system, but a TAWS system isn't necessarily EGPWS.

Regards;

TC

[Ramapriya]

Bob, guess I didn't frame the Q properly enough.
While I knew about the GPWS and TCAS individually, I wasn't sure
whether TCAS was equipped to deal with purely traffic or whether
accidental straying into terrain would also be taken care of.
I'm asking this because I remember an incident of many years ago where
an idiot in the ATC asked an Indonesian aircraft to turn 'left' when he
had to say 'right' and the unsuspecting blokes ran into a mountain. I
was wondering if that kinduva incident can be avoided with the TCAS...

Cheers,

Ramapriya


Bob Moore wrote:
> "Ramapriya" wrote
>
> > Does this get activated only when there's an aircraft in the
dangerous
> > vicinity or will it also trigger if the aircraft is hurtling
towards
> > some terrain such as a hill?
>
> In my generation of aircraft, (B-727) they are two different systems.
> First came the GPWS (Ground Proximity Warning System) and then some
> time later came the TCAS (Traffic Alert and Collision Advoidance
System).
>
> > And does every aircraft have this system these days, regardless of
> > size?
>
> No, only passenger jets are required to have them.
>
> Bob Moore

[Ramapriya]

Don Hammer wrote:
> On 1 Jan 2005 15:17:49 -0800, "george" > wrotD:
>
> Also, since TCAS has been mandated, there has been only one mid-air
> with equipped aircraft and it was because one crew ignored the
> warning. (UPS and Aeroflot in Switzerland)

????? You mean the TCAS only gives a warning, with the pilots having a
say on whether or not to take action?? I was under the impression that
the TCAS sytems talk to each other and take automatic action to avoid a
collision!!

To leave it to the pilots doesn't appear to be too much of an
advantage, with a relative speed of two planes being about 1000 mph
towards each other. Also, given the small reaction time, there's also a
chance, howsoever small, that the pilots could both take action that'll
precipitate a collision instead of avoiding one; both diving, for
example.

If it isn't automatic, I think the TCAS should be. For sure.
Ramapriya

[Bushy]

EBME, eye ball measuring equipment is the most important instrument you have
in the cockpit. ALL THE OTHER AIDS ARE ONLY AIDS!

Hope this helps,
Peter

[Chris]

"Ramapriya" > wrote in message
oups.com...
> Don Hammer wrote:
>> On 1 Jan 2005 15:17:49 -0800, "george" > wrotD:
>>
>> Also, since TCAS has been mandated, there has been only one mid-air
>> with equipped aircraft and it was because one crew ignored the
>> warning. (UPS and Aeroflot in Switzerland)
>
> ????? You mean the TCAS only gives a warning, with the pilots having a
> say on whether or not to take action?? I was under the impression that
> the TCAS sytems talk to each other and take automatic action to avoid a
> collision!!
>
> To leave it to the pilots doesn't appear to be too much of an
> advantage, with a relative speed of two planes being about 1000 mph
> towards each other. Also, given the small reaction time, there's also a
> chance, howsoever small, that the pilots could both take action that'll
> precipitate a collision instead of avoiding one; both diving, for
> example.
>
> If it isn't automatic, I think the TCAS should be. For sure.
> Ramapriya

TCAS alerts and instructions are what the pilot is supposed to follow. If
ATC and the TCAS conflict then the pilot is required to follow TCAS.

In the case over Germany the Russian obeyed ATC when they should have
followed the TCAS. The DHL plane obeyed TCAS but still ended up wrecked
because the Russian plane had not taken the action it was supposed to
follow.

As with all accidents measures taken earlier could have eliminated the need
for conflict resolution. There was only one controller on duty that night
covering a couple of sectors and he missed the problem as it was building
up. when he tried to raise the Russian plane he had difficulty and so it all
went on.

In the end the controller was murdered by, its claimed, avenging parents of
the 86 kids killed on the Russian plane.

Every regulation brought in is written in someone's blood.

[Bob Noel]

In article . com>,
"Ramapriya" > wrote:

> To leave it to the pilots doesn't appear to be too much of an
> advantage, with a relative speed of two planes being about 1000 mph
> towards each other. Also, given the small reaction time, there's also a
> chance, howsoever small, that the pilots could both take action that'll
> precipitate a collision instead of avoiding one; both diving, for
> example.

1) Reaction times are less of an issue with TCAS because normally
the system will advise the crew of traffic (called a traffic advisory or TA)
when the conflicting aircraft is (iirc) 40 seconds out. This allows the
crew to begin scanning for the potential conflict.

2) If the two aircraft involved in a potential conflict are both TCAS II
equipped, the systems will coordinate. That is, generally the higher
aircraft will get a "Resolution Advisory" or RA to climb (or possibly not
descend) while the lower aircraft will get a descent (or possibly not
climb).

>
> If it isn't automatic, I think the TCAS should be. For sure.

you have far more faith in automation than I.

btw - since TCAS can only see transponder-equipped aircraft, it
wouldn't be real smart to make the system automatic beause you
wouldn't want the system to fly the aircraft into conflict with
a non-transponder aircraft.

--
Bob Noel
looking for a sig the lawyers will like

[Ramapriya]

Bob Noel wrote:

> --
> Bob Noel
> looking for a sig the lawyers will like

ok, how about "A good lawyer knows the law, a great lawyer knows the
judge" :)

[James Robinson]

Chris wrote:
>
> TCAS alerts and instructions are what the pilot is supposed to follow. If
> ATC and the TCAS conflict then the pilot is required to follow TCAS.

Of interest, here was the Russian view of the priorities at the time:

http://www.aeronautics.ru/news/news002/news053.htm

I believe they have since changed their instructions to encourage the
pilots to follow TCAS recommendations.

[Ramapriya]

Bob Noel wrote:

> 1) Reaction times are less of an issue with TCAS because normally
> the system will advise the crew of traffic (called a traffic advisory
or TA)
> when the conflicting aircraft is (iirc) 40 seconds out. This allows
the
> crew to begin scanning for the potential conflict.

You know I'm not an aviator, but 40 secs don't appear that much. A few
secs to initially notice a warning and a few more till it properly
registers would take away much of the 40 secs. Moreover, the pilots
could easily be doing other things at the time - a loo break, chatting
up passengers while on autopilot, munching a snack, even flirting with
a hostess (hope I don't get flamed for suggesting that :))...

> > If it isn't automatic, I think the TCAS should be. For sure.
>
> you have far more faith in automation than I.

and why is it that you don't have faith in automation, Bob? Not having
to use brains, and doing something by rote instead, isn't necessarily a
disadvantage always. The chances of a well-programmed software
consistently doing a collision avoidance routine correctly are better
than two pilots doing so, I'd imagine.

Ramapriya

[William W. Plummer]

Ramapriya wrote:
> Don Hammer wrote:
>
>>On 1 Jan 2005 15:17:49 -0800, "george" > wrotD:
>>
>>Also, since TCAS has been mandated, there has been only one mid-air
>>with equipped aircraft and it was because one crew ignored the
>>warning. (UPS and Aeroflot in Switzerland)
>
>
> ????? You mean the TCAS only gives a warning, with the pilots having a
> say on whether or not to take action?? I was under the impression that
> the TCAS sytems talk to each other and take automatic action to avoid a
> collision!!
>
> To leave it to the pilots doesn't appear to be too much of an
> advantage, with a relative speed of two planes being about 1000 mph
> towards each other. Also, given the small reaction time, there's also a
> chance, howsoever small, that the pilots could both take action that'll
> precipitate a collision instead of avoiding one; both diving, for
> example.
>
> If it isn't automatic, I think the TCAS should be. For sure.

20+ years ago I knew one of the early developers of TCAS. She told me
about some of the attempts at conflict resolution. For example, they
started off with a rule that said if two planes were heading directly at
each other, "pass with the other plane on the right". Fortunately,
they did simulations: the result is the colliding planes form a
decreasing-radius spiral about each other, always with the other plane
on the right.

[Marty]

"Larry Dighera" > wrote in message
...
> On Sat, 01 Jan 2005 19:34:03 -0600, Don Hammer > wrote in
> >::
>
>>... it used to be a fairly frequent
>>occurrence for airliners to hit small aircraft. Of course the press
>>always got it the other way around. That's why we have to have
>>transponders is certain airspace in small aircraft.
>
> Here's the MAC that lead to mandatory TCAS:
> http://www.ntsb.gov/NTSB/brief.asp?ev_id=20001213X34444&key=2
>
>

Correct Larry,

The thing that gets me is that this collision would still have happened
because,

"N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP CONFIGURATION."

IOW, stand-by mode.

Marty

[Tobias Schnell]

On Sun, 2 Jan 2005 11:31:26 -0600, "Marty" >
wrote:

>The thing that gets me is that this collision would still have happened
>because,
>"N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP CONFIGURATION."
>IOW, stand-by mode.

I read this as a configuration "error" on the controller's display
(filtering out VFR targets, or targets above/below a certain
altitude).

Tobias

[AnthonyQ]

Ram, if I recall that incident correctly, ATC had repeatedly requested a
heading change and direction of turn (don't recall actual numbers) but the
flight crew repeatedly read back incorrectly. In the end the controller
deferred to the "obviously" more experienced and knowledgeable captain - and
gave in...

With respect to the capability of TCAS - it only interrogates the
transponders of nearby airplanes. It then figures out their distance away,
bearing and delta altitude (assuming a mode C or S transponder). It will
give a Resolution Advisory (Climb or Descend) instruction. It does not give
any terrain warning.

Anthony Quick

"Ramapriya" > wrote in message
ups.com...
> Bob, guess I didn't frame the Q properly enough.
> While I knew about the GPWS and TCAS individually, I wasn't sure
> whether TCAS was equipped to deal with purely traffic or whether
> accidental straying into terrain would also be taken care of.
> I'm asking this because I remember an incident of many years ago where
> an idiot in the ATC asked an Indonesian aircraft to turn 'left' when he
> had to say 'right' and the unsuspecting blokes ran into a mountain. I
> was wondering if that kinduva incident can be avoided with the TCAS...
>
> Cheers,
>
> Ramapriya
>
>
> Bob Moore wrote:
> > "Ramapriya" wrote
> >
> > > Does this get activated only when there's an aircraft in the
> dangerous
> > > vicinity or will it also trigger if the aircraft is hurtling
> towards
> > > some terrain such as a hill?
> >
> > In my generation of aircraft, (B-727) they are two different systems.
> > First came the GPWS (Ground Proximity Warning System) and then some
> > time later came the TCAS (Traffic Alert and Collision Advoidance
> System).
> >
> > > And does every aircraft have this system these days, regardless of
> > > size?
> >
> > No, only passenger jets are required to have them.
> >
> > Bob Moore
>

[Larry Dighera]

On Sun, 2 Jan 2005 11:31:26 -0600, "Marty" >
wrote in >::

>
>"Larry Dighera" > wrote in message
...
>>
>> Here's the MAC that lead to mandatory TCAS:
>> http://www.ntsb.gov/NTSB/brief.asp?ev_id=20001213X34444&key=2
>>
>
>Correct Larry,
>
>The thing that gets me is that this collision would still have happened
>because,
>
>"N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP CONFIGURATION."
>
>IOW, stand-by mode.
>

That's not the way I read the NTSB report. Here's the pertinent part:

INV REVEALED N4891F HAD INADVERTENTLY ENTERED THE LAX TERMINAL
CONTROL AREA (TCA) & WASN'T IN RADIO CONTACT WITH ATC. LAX TRACON
WASN'T EQUIPPED WITH AN AUTO CONFLICT ALERT SYS & THE ANALOG
BEACON RESPONSE FM N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP
CONFIGURATION. N4891F'S PSN WAS DISPLAYED BY AN ALPHANUMERIC
TRIANGLE, BUT THE PRIMARY TARGET WASN'T DISPLAYED DUE TO AN
ATMOSPHERIC INVERSION

What I infer from this is, that the controller's display wasn't
configured to display the Piper's transponder at the time of the
collision. That would imply that the controller reconfigured his
display between the time he noted the Piper squawking 1200 and the
time of the MAC.

As there is no mention of the Piper's altitude, I would assume it
wasn't squawking Mode C. That would be required for proper TCAS
operation if I'm not mistaken. So, I agree with your conclusion, but
for other reasons.

It would seem that the air traffic controller descended the airliner
into the path of the Piper whose alleged position at the time of the
MAC was inside the Terminal Control Area contrary to regulations,
without radio contact with ATC.

So it would appear that the NTSB found enough blame for everyone
involved, the airline PIC, the Piper PIC, the FAA, the ATC controller,
and even "OTHER/ORGANIZATION". If the Piper was eastbound and the
airliner northbound, the Piper PIC may have deviated from regulations
by failing to yield the right-of-way also.

Despite the failure of the pilots to see each other in time to alter
course, and the Pipe PIC's possible incursion into TCA airspace, it
_feels_ like the controller was in the best position to prevent this
tragedy due to the Piper's position being displayed by an
"alphanumeric triangle" on the controller's scope. I fail to
understand why the lack of display of the Piper's primary target was
significant. I know that today LAX controllers' workload can be
overwhelming at morning and evening traffic peaks during IMC. But, in
VMC just before noon, one would think the controller might have been
aware of the possible conflict.



(There's a summary here: http://www.ntsb.gov/publictn/1987/AAR8707.htm
)

[Bob Noel]

In article om>,
"Ramapriya" > wrote:

> > > If it isn't automatic, I think the TCAS should be. For sure.
> >
> > you have far more faith in automation than I.
>
> and why is it that you don't have faith in automation, Bob?

because I've seen how avionics software systems are developed

because I've seen the state-of-the-art wrt safety-critical software.

>Not having
> to use brains, and doing something by rote instead, isn't necessarily a
> disadvantage always. The chances of a well-programmed software
> consistently doing a collision avoidance routine correctly are better
> than two pilots doing so, I'd imagine.

1) the chances of actually having that "well-programmed" software
is pretty

2) I suggest you check out the accuracy of the TCAS II system wrt
azimuth for conflicting traffic. I'm just a software guy, but my hardware
guys tell me that the 4 element (4 pole?) antenna used doesn't give
an azimuth accuracy of even +/- 15 degrees.

--
Bob Noel
looking for a sig the lawyers will like

[Don Hammer]

>20+ years ago I knew one of the early developers of TCAS. She told me
>about some of the attempts at conflict resolution. For example, they
>started off with a rule that said if two planes were heading directly at
>each other, "pass with the other plane on the right". Fortunately,
>they did simulations: the result is the colliding planes form a
>decreasing-radius spiral about each other, always with the other plane
>on the right.


TCAS II will only give a climb or descend command along with the rate
( shown as a line on the ROC) needed. If both have Mode S (required
if you have TCAS) then the two transponders will talk to each other
and figure out who will climb and who will descend and command the
crew to do it. If one is Mode C then the software decides if a climb
or decent would be appropriate.

TCAS I gives advisories only.

http://www.rannoch.com/tcasf.html
http://www.aerowinx.de/html/tcas.html

Some info


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[Capt.Doug]

>"AnthonyQ" wrote in message > It does not give any terrain warning.

In the US, starting this quarter, all turbine powered equipment with six
passenger seats or more will be required to have Terrain Awareness Warning
Systems (TAWS) installed. This equipment is required on private as well as
commercial equipment, freight or passenger, jet or turboprop. TAWS uses GPS
positioning compared against topographic mapping to determine if a threat
exists. A screen shows the mountains near you. Red is bad. Green is okay.
This equipment would have been helpful in the incident Ram is asking about.

D.

[Capt.Doug]

>"Ramapriya" wrote in message >
> You know I'm not an aviator, but 40 secs don't appear that much. A few
> secs to initially notice a warning and a few more till it properly
> registers would take away much of the 40 secs.

For a crew that is trained to respond to a TCAS alert by instinct, 40
seconds is plenty.

>Moreover, the pilots
> could easily be doing other things at the time - a loo break, chatting
> up passengers while on autopilot, munching a snack, even flirting with
> a hostess (hope I don't get flamed for suggesting that :))...

With a professional crew, only one pilot is chatting up the hosties. The
other is flying. A professional crew always has one of the pilots placing
his/her attention on the plane, even with the auto-pilot on.

> and why is it that you don't have faith in automation, Bob? Not having
> to use brains, and doing something by rote instead, isn't necessarily a
> disadvantage always. The chances of a well-programmed software
> consistently doing a collision avoidance routine correctly are better
> than two pilots doing so, I'd imagine.

Bob understands the limitation of the equipment. It is great stuff. TCAS is
a huge inprovement in safety. However, it isn't infallible. I was on the
jumpseat last week when a fellow crew received a TCAS warning even though a
real threat did not exist. Well-trained pilots who are supplied with good
information will always be the best safety equipment.

For example- the A-320 you have experienced was designed so that idiots can
fly it. The idiots still manage to crash the A-320.

D.

[Ash Wyllie]

AnthonyQ opined

>Ram, if I recall that incident correctly, ATC had repeatedly requested a
>heading change and direction of turn (don't recall actual numbers) but the
>flight crew repeatedly read back incorrectly. In the end the controller
>deferred to the "obviously" more experienced and knowledgeable captain - and
>gave in...

>With respect to the capability of TCAS - it only interrogates the
>transponders of nearby airplanes. It then figures out their distance away,
>bearing and delta altitude (assuming a mode C or S transponder). It will
>give a Resolution Advisory (Climb or Descend) instruction. It does not give
>any terrain warning.

Maybe if we put mode C Transponders on every mountain top... And radio tower
for that matter.

>"Ramapriya" > wrote in message
ups.com...
>> Bob, guess I didn't frame the Q properly enough.
>> While I knew about the GPWS and TCAS individually, I wasn't sure
>> whether TCAS was equipped to deal with purely traffic or whether
>> accidental straying into terrain would also be taken care of.
>> I'm asking this because I remember an incident of many years ago where
>> an idiot in the ATC asked an Indonesian aircraft to turn 'left' when he
>> had to say 'right' and the unsuspecting blokes ran into a mountain. I
>> was wondering if that kinduva incident can be avoided with the TCAS...
>>
>> Cheers,
>>
>> Ramapriya
>>
>>
>> Bob Moore wrote:
>> > "Ramapriya" wrote
>> >
>> > > Does this get activated only when there's an aircraft in the
>> dangerous
>> > > vicinity or will it also trigger if the aircraft is hurtling
>> towards
>> > > some terrain such as a hill?
>> >
>> > In my generation of aircraft, (B-727) they are two different systems.
>> > First came the GPWS (Ground Proximity Warning System) and then some
>> > time later came the TCAS (Traffic Alert and Collision Advoidance
>> System).
>> >
>> > > And does every aircraft have this system these days, regardless of
>> > > size?
>> >
>> > No, only passenger jets are required to have them.
>> >
>> > Bob Moore
>>




-ash
Cthulhu in 2005!
Why wait for nature?

[Matt Barrow]

"Ash Wyllie" > wrote in message
...
> AnthonyQ opined
>
> >Ram, if I recall that incident correctly, ATC had repeatedly requested a
> >heading change and direction of turn (don't recall actual numbers) but
the
> >flight crew repeatedly read back incorrectly. In the end the controller
> >deferred to the "obviously" more experienced and knowledgeable captain -
and
> >gave in...
>
> >With respect to the capability of TCAS - it only interrogates the
> >transponders of nearby airplanes. It then figures out their distance
away,
> >bearing and delta altitude (assuming a mode C or S transponder). It will
> >give a Resolution Advisory (Climb or Descend) instruction. It does not
give
> >any terrain warning.
>
> Maybe if we put mode C Transponders on every mountain top... And radio
tower
> for that matter.
>

Ummm...doesn't TAWS read a map database that holds such obstructions?


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

[Bob Noel]

In article >,
"Matt Barrow" > wrote:

> Ummm...doesn't TAWS read a map database that holds such obstructions?

DTED (terrain data) is pretty constant. Vertical obstructions are quite
the challenge in that it is almost impossible for the various database
providers to keep up with every tower that is out there.

--
Bob Noel
looking for a sig the lawyers will like

[Marty]

"Larry Dighera" > wrote in message
...
> On Sun, 2 Jan 2005 11:31:26 -0600, "Marty" >
> wrote in >::
>
>>
>>"Larry Dighera" > wrote in message
...
>>>
>>> Here's the MAC that lead to mandatory TCAS:
>>> http://www.ntsb.gov/NTSB/brief.asp?ev_id=20001213X34444&key=2
>>>
>>
>>Correct Larry,
>>
>>The thing that gets me is that this collision would still have happened
>>because,
>>
>>"N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP CONFIGURATION."
>>
>>IOW, stand-by mode.
>>
>
> That's not the way I read the NTSB report. Here's the pertinent part:
>
> INV REVEALED N4891F HAD INADVERTENTLY ENTERED THE LAX TERMINAL
> CONTROL AREA (TCA) & WASN'T IN RADIO CONTACT WITH ATC. LAX TRACON
> WASN'T EQUIPPED WITH AN AUTO CONFLICT ALERT SYS & THE ANALOG
> BEACON RESPONSE FM N4891F'S X-PONDER WASN'T DISPLAYED DUE TO EQUIP
> CONFIGURATION. N4891F'S PSN WAS DISPLAYED BY AN ALPHANUMERIC
> TRIANGLE, BUT THE PRIMARY TARGET WASN'T DISPLAYED DUE TO AN
> ATMOSPHERIC INVERSION
>
> What I infer from this is, that the controller's display wasn't
> configured to display the Piper's transponder at the time of the
> collision. That would imply that the controller reconfigured his
> display between the time he noted the Piper squawking 1200 and the
> time of the MAC.
>
> As there is no mention of the Piper's altitude, I would assume it
> wasn't squawking Mode C. That would be required for proper TCAS
> operation if I'm not mistaken. So, I agree with your conclusion, but
> for other reasons.
>

IIRC it is (or was) common practice to eliminate "1200s" from displays in
high traffic areas for clarity purposes. I don't know if the Piper was
equipped with Mode C at the time or not.
My statement about the X-Ponder being in stand-by was distant memory of a
report that I can't cite where from. Maybe a news report? I dunno, I wish I
could remember.
I can only agree with your reasoning on the issue.

Marty

[Matt Barrow]

"Bob Noel" > wrote in message
...
> In article >,
> "Matt Barrow" > wrote:
>
> > Ummm...doesn't TAWS read a map database that holds such obstructions?
>
> DTED (terrain data) is pretty constant. Vertical obstructions are quite
> the challenge in that it is almost impossible for the various database
> providers to keep up with every tower that is out there.

They use the same data that the NACO/FAA provides, with the same frequency.


Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

[James M. Knox]

"Ash Wyllie" > wrote in
:
>
> Maybe if we put mode C Transponders on every mountain top... And radio
> tower for that matter.

Actually, that proposal was not too far off the mark. One suggestion for
ADS-B is to do just that - put a "squirter" (transmit only) on tall
antennas and other non-obvious obstructions. Total cost in parts is about
$30 (plus the money for FAA/FCC certification <G>). Operating power is
very low, so the long term cost to the operator of a tall transmitting
tower should be much less than the current required strobe light.

jmk

[Don Hammer]

>Actually, that proposal was not too far off the mark. One suggestion for
>ADS-B is to do just that - put a "squirter" (transmit only) on tall

I think the word is squitter

[James M. Knox]

Don Hammer > wrote in
:

>
>>Actually, that proposal was not too far off the mark. One suggestion
>>for ADS-B is to do just that - put a "squirter" (transmit only) on
>>tall
>
> I think the word is squitter

I think you are right.

jmk