I'm curious how departures and climb is managed at high altitude airports (ex. KTEX) with normally aspirated GA aircraft (Cessna 172, Bonanza G36). This is an area of flight simming that I'd like to become more proficient at but am struggling a bit practicing at Telluride. I'm leaning the mixture to reach peak EGT during my run up but am noticing that the climb is incredibly slow while maintaining Vx. Even a moderate day (59 degrees F, 30.14 "Hg, dew point 53) yields a density altitude of just over 11,000 feet. How do light aircraft navigate this terrain where minimum safe altitudes are 16,600' above sea level? That density altitude is over the service ceiling of most GA aircraft, even on cool days.

 

Thank you

You might prefer to lean for max RPM instead.  This is how I do it in a sim.

Hook

Some aircraft just can't handle high altitude airports.

When I was first learning to fly in a Luscombe on floats in the San Francisco Bay Area the FBO had a couple of Republic SeaBees they used for charter.  

One summer afternoon my flight instructor invited me to ride along with a passenger he was flying to Lake Tahoe.  We arrived in late afternoon.  The temperature was over 90 degreesF.  The density altitude (Lake Tahoe is over 7,000 feet) was too high to get the SeaBee to take off from the water.  We had to remain overnight and takeoff the next morning after it had cooled down.

It was an object lesson in density altitude for this student pilot at the time.

Not all light aircraft are meant for high altitude operation.

When I moved to Roswell (Field Elevation 3600ft) the Cessna 152s we rented had climb props to compensate for the density altitude in the summer when the temperatures typically ran over 90 degrees almost every day.

Noel

6 minutes ago, birdguy said:

Some aircraft just can't handle high altitude airports.

Yes. For fun just try and takeoff in a 172 from Quito, Ecuador 🍻

Telluride is certainly a challenging airport.  I did a short hop KTEX-KDEN recently and even in the King Air the climb felt sluggish...not confidence inspiring when you’re surrounded by mountains that are higher than you!

Sometimes you just have to climb slowly and make the curvature of the earth work for you lol

Edited August 20, 20205 yr by regis9

Good article here:     https://www.mountainflying.com/Pages/articles/Leaning_mixture.html

7 hours ago, Hyperfocal said:

How do light aircraft navigate this terrain where minimum safe altitudes are 16,600' above sea level?

The minimum safe altitudes are for IFR /IMC flying. 
You can still fly below them if you’re maintaining visual separation from the terrain in good weather of course.

Its not just GA that has issues, many years ago I used to fly an old twin engined turbo prop airliner known as an HS 748 around mountainous terrain in South East Asia, things you do when you’re young and desperate.

Because of the full load and ISA + 18C temperatures down there you could only just get them up to MSA which was normally 12-14,000ft, if you lost an engine you were going down below MSA no doubt about it, you just had to hope it was a sunny day!

Those early Rolls Royce Dart engines had a mechanism not unlike a mixture control in a piston , called a fuel trimmer.

You’d use a little rotary slide rule computer device on the overhead panel to enter with altitude and temperatures and it would give you a percentage number to trim the fuel back to so you got max power out of the engine without busting the turbine gas temperature limits.

Nowadays when crossing the Himalayas for example there’s pre calculated escape routes in case of engine failures in the big jets.

I'd like to thank everybody for the helpful suggestions and links to further reading. It sounds like I'm likely not doing anything terribly wrong, but flying in these areas is simply extremely difficult in favorable conditions and impossible for certain aircraft when hot and humid.

15 hours ago, jon b said:

Nowadays when crossing the Himalayas for example there’s pre calculated escape routes in case of engine failures in the big jets.

I had thought most airliners avoid the Himalayas altogether due to challenges with an emergency depressurization descent?

19 hours ago, W2DR said:

Good article here:     https://www.mountainflying.com/Pages/articles/Leaning_mixture.html

That was really an interesting read - thank you!