Plane down on Vail Pass

Safe mountain flying involves a constellation of skills. Around here
(Colorado) clouds often build up in the late afternoons with bases at13,000
to 15,000; summits are 13,000 to 14,000, so to get home we fly the passes,
typically 10,000 to 12,000. This means flying (typically) at 12,500. It
can be done safely if you understand the terrain and the wind --
specifically how the wind rises and falls along the valley walls, where
spillover turbulence is, and where you'll find lift as opposed to downdraft
if you have to make a short 180. When you fly here a lot you learn each of
the passes and what the wind does depending on speed and direction. You
need to know how to do a chandelle. Pointless to even try lightplane flight
upwind if the wind is 25 knots at the summit: some downdrafts will be 2000
fpm. Downwind (eastbound) flight is safer but there's lots of turbulence on
the lee side. Etc.

Given clear weather and adequate power, I keep at least 1500 terrain
clearance just to avoid the spillover rotor. Anyway, over wilderness
areas -- which includes most of the Continenal Divide terrain -- the Forest
Service wants 2000 feet of terrain clearance to avoid spooking wildlife.
This is not a trivial issue when animals are stressed in winter or during
drought.

On calm days it is fun to scoot lower. CAP and pipeline missions routinely
fly this terrain, safely, at 500 agl. Before doing it, it's instructive to
figure out your best climb angle at the appropriate density altitude,
compare it to the angle of the rising terrain -- and consider what you'd do
if you lost power or ran into unexpected wind.

I can't figure out why the Vail Pass Cherokee couldn't climb out of trouble.
The road is a 3% grade, and with that engine he should have been able to
climb at 500fpm -- a 5% grade at 90 knots. Something else was going on
there -- overloaded airplane, weak engine, bad leaning, wrong prop setting,
downdraft side of the valley, fuel starvation ???? If they were below
10,000 feet over the town of Vail, it's because they were sightseeing -- the
ridgelines on the north and south sides of the valley are about 11,500 in
town, rising as you go eastward.

Sorry to obsess about this one, but it's my back yard and I want to know how
to avoid whatever it was that ruined this flight.

Seth

"Newps" wrote in message
...


Ron Lee wrote:

Newps wrote:

Ron Lee wrote:

and I usually have beaucoup distance between me and terra firma.


Then you're not mountain flying.


Take a look at these pics and tell me that I am not mountain flying:

You're not.



Of course if you only consider it mountain flying if you can count
pine cones that is your choice.

That's the definition of mountain flying.