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.

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.

300 horsies with only two on board (plus lord knows how much baggage) oughta
be more than 500 fpm. Unless it was violently turbulent, and the passenger
didn't indicate this was the case.


Something else was going on
there -- overloaded airplane,

2 souls on board and I didn't see any indication of baggage piled up over
the rear windows or strewn about the countryside.


weak engine,

Possibly, but even at compression limits you'd be getting 90%+ of rated
power. With the engine as bunged up as it is, all you can do is rely on the
readings at the last annual (if they were even recorded in the log).


bad leaning,

Only if he REALLY screwed up. When you come from Green River/Rock Springs
the first thing you learn in an aircraft is leaning.


wrong prop setting,

Not enough of the prop left to do a decent analysis.



downdraft side of the valley,

Possibly. Didn't your instructor teach you a chandelle as the fastest way
to get the hell out of there in a minimum of room?



fuel starvation ????

As I remember the Cherokee has a single "on-off" fuel lever to prevent that
sort of thing. I doubt fuel exhaustion either or somebody would have
mentioned that there was no fuel on the ground.




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.

I feel the same way when we lose one in the Sierra. Worse when I know the
folks.



Jim

"Newps" wrote

On clear sunny days after about 11 am it
gets too turbulent to fly in the mountains, you run into those
downdrafts you talk about. Get up early and you can fly over the
mounatin passes at a few hundred feet agl as easily as you fly over
anywhere else.

What was that noise I just heard?

Oh, never mind. It was just my BS detector going off.

Mountain waves can be present at any time of the day, when the wind
conditions are right. Remind me not to take any mountain flying lessons
from you.
--
Jim in NC

"Seth Masia" wrote

Something else was going on
there -- overloaded airplane, weak engine, bad leaning, wrong prop
setting,
downdraft side of the valley, fuel starvation ????

The report I read had the passenger saying that they were losing power.
--
Jim in NC

I'm still thinking the density altitude issue. Lots of horsepower
does not automatically mean higher service ceiling.

"Morgans" wrote in message
...

"Newps" wrote

On clear sunny days after about 11 am it
gets too turbulent to fly in the mountains, you run into those
downdrafts you talk about. Get up early and you can fly over the
mounatin passes at a few hundred feet agl as easily as you fly over
anywhere else.

What was that noise I just heard?

Oh, never mind. It was just my BS detector going off.

Yeah...you do BS consistently. Full of it as always.


Mountain waves can be present at any time of the day, when the wind
conditions are right. Remind me not to take any mountain flying lessons
from you.

And maybe if you can't comprehend written context, lessons would be
worthless taken from anyone.

Newps wrote:

Well that's the skill level you need to attain. It's not safe to fly in
the mountains all the time. On clear sunny days after about 11 am it
gets too turbulent to fly in the mountains, you run into those
downdrafts you talk about. Get up early and you can fly over the
mounatin passes at a few hundred feet agl as easily as you fly over
anywhere else.

I guess the mountain wave downdraft I encountered around 830 AM was my
imagination.

Ron Lee

"Ron Lee" wrote in message
...
Newps wrote:

Well that's the skill level you need to attain. It's not safe to fly in
the mountains all the time. On clear sunny days after about 11 am it
gets too turbulent to fly in the mountains, you run into those
downdrafts you talk about. Get up early and you can fly over the
mounatin passes at a few hundred feet agl as easily as you fly over
anywhere else.

I guess the mountain wave downdraft I encountered around 830 AM was my
imagination.

It must have been since he said it ALWAYS happens the way he inferred.

I would define "Mountain Flying" the same as Newps, where the airplane is
below ridge level (in and amongst the mountains) to perhaps a thousand feet
above the ridges.. Is an airliner flying seven miles above the highest
peaks "mountain flying?

Mike
MU-2


"Blanche" wrote in message
...
Mike Rapoport wrote:
Those are pictures of flying well over the terrain and quite a distance
from
the mountains, they do not really depict "mountain flying"

So -- can we agree on a definition of "mountain flying" before we
start getting snotty?

"Morgans" wrote in message
...

"Newps" wrote

On clear sunny days after about 11 am it
gets too turbulent to fly in the mountains, you run into those
downdrafts you talk about. Get up early and you can fly over the
mounatin passes at a few hundred feet agl as easily as you fly over
anywhere else.

What was that noise I just heard?

Oh, never mind. It was just my BS detector going off.

Mountain waves can be present at any time of the day, when the wind
conditions are right. Remind me not to take any mountain flying lessons
from you.
--
Jim in NC


Since you totally missed his point, perhaps you do need to take some
instruction.

Mike
MU-2