TRAFFIC ALERT! TRAFFIC ALERT!

....Skyhawk XXX. Traffic is 12 o'clock, two miles, altitude 7600, closing.
Recommend turn left 30 degrees immediately."

My buddy (we'll call him CJ) rolled into a hard left bank and added some
down-push to the yoke when a glance at the altimeter told him he was at
7,500.
"XXX, traffic now one mile."
With the wing rolled up about 60 degrees, CJ saw the opposing traffic go
by at 2, then 3, then 4 o'clock. Separation then was probably 1/2 mile or
more. He could only identify the other aircraft as a high wing single,
tannish in color, make unknown.
He keyed the mike and said, "Joshua, XXX, traffic in sight, no factor."
"Roger, XXX, resume normal navigation, maintain VFR."
"Roger, resume normal navigation, XXX. Thanks for the head-up," CJ
replied as he added throttle to regain the 400 feet he'd lost and turned
back toward the east to recapture the 358-degree course line on his
yoke-mounted GPS.
Leveling off at 7,500, CJ contemplated calling Joshua Control and asking
if they had the tail number of that yahoo he'd done the aerial dance with.
Then came the epiphany. There it was, right in front of him. The altimeter
was nailed at 7,500 and the DI was right on the bug set at 358. CJ was the
yahoo.
If you've ever flown along the east side of the Sierra Nevada, you know
the Owens Valley squeezes down to a narrow route with 12,000 to 14,000
ridges to the west and the 10,000 to 14,000 White Mountain range to the
east. Down near Owen's Lake, R-2505 owned by the Naval Air Warfare Center at
China Lake makes the east side even closer. It is not uncommon for
horizontal separation to be less than a mile.
Flying northbound out of IYK (Inyokern, CA) to BIS (Bishop, CA), CJ had
been initially tracking 005-degrees. When he rounded a high terrain feature,
he jinked left to head to BIS direct. By then he'd dialed in the elevator
trim for practically hands-off level flight. The winds were dead calm except
for the usual rivers of air flowing out of the deeper canyons causing some
negligible burbles. The nearest cloud was somewhere out of sight and the
boundary between sky and mountains looked like it had been carved with a
razor blade.
I'm not trying to excuse CJ's lack of attention to details and the fact
that his course change required a corresponding change of altitude. He blew
it. The incident took all the fun out of the flight and after doing a 180
course reversal, CJ took the airplane back to IYK and parked it for two
weeks.
The day after the incident he sent an ASRS form in to report his dumb
mistake with the hope that it will help in the future.
Things could have been bad on that Tuesday morning except for an alert
ATC at Joshua Approach and the fact that CJ always requests flight
following. Oh, one last thing, CJ did descend to a lower when he crossed the
jink-point on the way home.

Go Fly!

Casey Wilson
Freelance Writer
and Photographer

There it was, right in front of him. The altimeter
was nailed at 7,500 and the DI was right on the bug set at 358. CJ was the
yahoo.

CJ should not be so hard on himself. The line between even+ and odd+
may be an exact mathematical number, but nobody can fly that exactly,
and even if they could, there would be people flying 358 at the same
altitude as people flying 181. It's a fact of life. And all it takes
is a slight crosswind for the 181 degree aircraft to need to fly 177 to
maintain course, and then 181 again. There is going to be some overlap.
This doesn't even count the folks descending or climbing through an
altitude.

The hemisphere rule is intended to get "most" folks out of the way of
"most other" folks, "most of the time". I do not consider those who are
on the edge of the hemisphere to be yahoos, whether they be even+ or
odd+. That's what eyeballs are for.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

On Sun, 25 Jun 2006 11:53:21 GMT, Jose
wrote:

There it was, right in front of him. The altimeter
was nailed at 7,500 and the DI was right on the bug set at 358. CJ was the
yahoo.

CJ should not be so hard on himself. The line between even+ and odd+
may be an exact mathematical number, but nobody can fly that exactly,
and even if they could, there would be people flying 358 at the same
altitude as people flying 181. It's a fact of life. And all it takes
is a slight crosswind for the 181 degree aircraft to need to fly 177 to
maintain course, and then 181 again.

I thought the hemispherical rules were based on magnetic course, not
heading?

"Jose" wrote in message
. com...
And all it takes is a slight crosswind for the 181 degree aircraft
to need to fly 177 to maintain course, and then 181 again.

True, but as long as the course is being maintained, the corresponding
altitude doesn't change (the hemisphere rule applies to course, not
heading).

I agree with your larger point that (even aside from climbs and descents)
the hemisphere rule doesn't prevent near-head-on flight in the vicinity of
180 or 360 degree courses. For that reason, when VFR, I prefer to avoid such
courses if feasible; instead, I plot a course that zig-zags about ten
degrees away from the borderline direction. If nothing else, traffic is a
bit more conspicuous when its orientation is oblique so that the fuselage
profile becomes visible.

--Gary

"Jose" wrote in message
. com...

And all it takes is a slight crosswind for the 181 degree aircraft to need
to fly 177 to maintain course, and then 181 again.

The hemispheric rule is based on the course, not the heading needed to hold
it.

The hemispheric rule is based on the course, not the heading needed to hold
it.

Yes, I thought so, but I wanted to respond in the context, rather than
challenge the context. Some pilots do choose based on heading, and if
you have no charted course (as in "let's go sightsee") heading becomes a
stand-in. Something else to watch out for.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

Casey Wilson N2310D @gmail.com wrote:

I'm not trying to excuse CJ's lack of attention to details and the fact
that his course change required a corresponding change of altitude. He blew
it. The incident took all the fun out of the flight and after doing a 180
course reversal, CJ took the airplane back to IYK and parked it for two
weeks.

As I am not familiar with the area, what was the ground elevation at that
point? Was "CJ" above 3,000 feet above the ground or below it? As you
know, odd/even cruise altitudes are required above 3,000 feet AGL.

Also, there are many other, more common and legitimate opportunities to
bump into aircraft. One or both could be climbing up to a cruise altitude,
descending to an airport or an interim altitude, or any permutation
thereof.



--
Peter

"Casey Wilson" N2310D @ gmail.com wrote in message
news:twung.1224$Gh.204@trnddc02...
...snip
Leveling off at 7,500, CJ contemplated calling Joshua Control and
asking if they had the tail number of that yahoo he'd done the aerial
dance with.

How/why would CJ want the other aircraft's tail number?

snip
Go Fly!

Casey Wilson
Freelance Writer
and Photographer

On Sun, 25 Jun 2006 11:33:45 GMT, "Casey Wilson" N2310D @ gmail.com
wrote:

...Skyhawk XXX. Traffic is 12 o'clock, two miles, altitude 7600, closing.
Recommend turn left 30 degrees immediately."


A few weeks ago I was flying out of my base airport on a short cross
country flight. As I climbed out of runway 23 the controller told me
to make a "structured" right downwind and to maintain 1000'. The word
"structured" threw me for a second. I had never heard that term used
before. But I assumed he meant to fly a standard closed circuit which
I did. I established myself on the downwind and nailed it at 1000'
because the controller had traffic at 1500'. All is good until I get
down to the arrival end of the runway abeam the numbers. Then out of
the corner of my eye, in a split second a Cessna passed directly
under me about ten degrees off the nose. I believe he was less than
100' below me. I never thought about it again and proceeded with the
flight. But I begin to wonder about it the next day. The day before I
took this aformentioned flight I had schedlued a visit to the control
tower for the next weekend. So when I went for the visit I mentioned
the incident the controller. It happened to be the same guy that was
working me the previous weekend. He remembered the particular aircraft
in question and said that they in the contrl tower were taken
completely by surprise by that Cessna driver. We talked about it for a
little while and moved on to other topics. (As a side note I told him
that the word "structured" confused me for a second. He said that it
was something he had used as a military controller and that it might
be best to rethink his use of it now.)

The reason I mention this close encounter is that I have always been
hesitant about how well I can spot aircraft at a distance. I felt
that I should have seen this guy at least a few miles out but never
did. Depending on the sun angles, the haze, the background clutter
etc., I am not completely confident yet on my ability to be able to
immediately spot an aircraft 3 or 5 miles out. And in this case I
never saw him until he was right under me.

Is it resaonble to expect that Casey or the other pilot should have
been able to see each other 3, 4 or 5 miles out? Or do you have to
have the infamous eyesight of Chuck Yeager. For the average GA pilot
what would be the expected level of visual acuity? When conditions are
right I can see aircraft 3 to 4 miles out but when the controllers
report traffic that far out it can take me some time to spot it.
Sometimes I never can because of the conditions. Usually it takes the
lightreflecting off the aircraft just rightfor me to see it.

Does the ability to spot other aircraft improve with experience?

Kirk

The reason I mention this close encounter is that I have always been
hesitant about how well I can spot aircraft at a distance. I felt
that I should have seen this guy at least a few miles out but never
did. Depending on the sun angles, the haze, the background clutter
etc., I am not completely confident yet on my ability to be able to
immediately spot an aircraft 3 or 5 miles out. And in this case I
never saw him until he was right under me.

It's not so much being able to =see= him, as being able to =notice= him.
I can see traffic many miles away, once I notice it. Sometimes
however I have to notice it again before I can see it again. Motion, a
glint of sun, a good silhouette against a cloud, these things help.

Does the ability to spot other aircraft improve with experience?

Yes, some. However, it will probably never be excellent. The field of
good vision is narrow, and the eye doesn't actually send an image to the
brain, it pre-processes it. Different parts of the retina (different
areas of view) are pre-processed differently. There's a lot of sky to scan.

Lots of experienced pilots, myself included, miss lots of targets that
are called out. That's why four eyes are better than two.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.