Shamon's video, re Crash at Angel Fire, points out the negative and positive effect of wind over terrain. Negative =downdraft. Positive= airspeed increase for into wind takeoff and updraft. He also well pointed out that wind management involves much more than taking off upwind. At Angel Fire, a down drainage egress (toward the lake), could be safer with a quartering tailwind.

The cushion in the POH numbers are adequate for takeoff and landing, but density altitude degradation of climb rate doesn't tell the whole story. We can't safely expect 300 fpm climb, at a certain DA, in a 2,000 fpm downdraft. Vx doesn't exist up here and a Vy climb, expecting 300 fpm, would be -1700 fpm for a longer period of time than at cruise airspeed. By using ridge lift on the rising terrain east of Angel Fire shamons is able to get more than book rate of climb to safely exit south.

Discussing wind energy, my pipeline patrol supervisor said to the owner, "Jim Dulin doesn't believe an airplane will climb." Actually I don't put any faith in it, regardless of the numbers.

Other high DA airport considerations:
The runway is long. Cruise airspeed, zoom reserve, can generally be developed in low ground effect.
We are above the tree line and the single runway is wide. Angle across (crosswind) takeoff and landing is generally possible.
No energy zapping climb is generally required (down drainage egress) until favorable ridge lift or thermal lift located.

Gallup New Mexico is a typical high desert airport. The dotted lines indicating the Puerco River and Twin Buttes Wash mean intermittent stream. Think always dry. The two join, to make the classic wine glass west of the airport and between "Puerco River" and "Frontage Road on the topo map.

The examiners who check whether you have researched all available information for the flight seldom ask if we checked a topo to determine which way is down hill. The drainage is dry except a few minutes of flash flood. You could drive to East Gallup to view the hogback, The trading post east up I -40 called Continental Divide should be a clue. At the airport it is dangerously not obvious.

So west is the safer egress given one more important consideration. If we are still in trouble where the high voltage transmission line crosses the drainage, under is far safer than over. I have been there. Plenty of vertical space available.

With SW winds, the mesas north of 40 should provide ridge lift. With west or northwest winds, the rising terrain south of 40 should provide ridge lift.

Will running the numbers prevent ever needing consider this information? Absolutely not!

Primary in W. CO in the summertime, field elevation was 5000’. C150 and a 200# CFI with 10,000 hrs right seat. To say it was educational in terms of energy management was an understatement. And I’ve forgotten damn near all of it. Keep your writing coming Jim.

Physics has changed since you old farts learned to fly. These days you can't fly in the mountains unless you have a 180hp Cub or a ponked C180. You'll die if you try with something less.

We figured the engine and the math would get us off the airport. From there, it had to be pilot stuff. Thermal, orograraphic, down hill? Whatever worked.

I enrolled into the Mountain Flying Clinic the NMPA puts on a couple years back (couldn't follow through attending as life got in the way...) and I was surprised to find that they would not give flight instruction in anything less than 180 HP. My observation to the instructor is that disqualifies most 172's and most high wing Pipers (a LOT of aircraft). The DA you will encounter at the airports (of which AXX is one) gets pretty humbling when you are sporting over 400 lbs of pilot and CFI, fuel, and weight that brings the aircraft to within their prescribed 90% of the aircraft's MTOW for the flight.

Teaching the test, PTS, was just too unrealistic for me at high DA instructor jobs. I explained the situation to students and gave them the option. Flying safely or test prep. Eventually I became the flying teacher for primary as well as certified. My primary students soloed early, did zero electronics cross country, and flight tested with their peers anyway.

This talk is all foolishness.

The real secret to taking off in an underpowered bird is to stick your arm straight out the window and hold your hand at an angle. Works even better if your passenger does it, too.

Remember to shave your arms for less drag.

Salida, ANK, used to be shorter and definitely a one way deal down the 1.88% grade of runway 6 toward the Arkansas river. Because drainage is significant and solid blue, downhill is quite visible on the sectional. The slope of runway 24 is half the maximum slope of 6% on highway 50 up to Monarch pass.

Granted,getting off at oh dark thirty will leave some engine climb ability and as the sun comes up the pooled cold air begins rising into both east and west mountains. Toward ten and after, however, engine climb diminishes and wind energy becomes greater.

Both Monarch and Poncha passes have significant valley between ridges systems. The hook toward Monarch pass can require crossing the valley to the other ridge.

RE NMPA Mt flying class. I took the class with a 100HP Rans S7. I've fly two up in the mountains of NM, CO, AZ, UT and Idaho. Never a problem even with airpots over 9,000' elevation. Just learn how to fly the plane.

Power to weight is sort of like cigarettes in the old Army. "Smoke em if you've got em, bum em if you don't." In the heat of the day, low power to weight guys have to bum free energy from mother nature. Seems some who've got em have takeoff and departure problems from time to time as well. I know several twin guys who survived engine failure on high DA takeoff by pulling power on the running engine and landing in the desert. Yes, they were headed down drainage.

ShadowAviator wrote:This talk is all foolishness.

The real secret to taking off in an underpowered bird is to stick your arm straight out the window and hold your hand at an angle. Works even better if your passenger does it, too.

Remember to shave your arms for less drag.

Even better if you can get them to flap their arm up and down synchronized exactly with yours... Of course, if they get out of phase, it's all for naught...

Gastons, 3MO, is deceptively dangerous because it is only 479' and decently long for grass strips in the area. Up the White river to the west is not a significant grade, on the river, but is over tall trees and runs into Bull Shoals Dam.

East, the preferred route, is down drainage over bottom land. It quickly runs into a four hundred feet cliff, unless we follow the river bottom over, or under, the high voltage transmission line that comes off the bluff and crosses the river very high with balls. A 45 degree right energy management or rudder in low ground effect turn will easily put us over the wire on the opposite bottom.

Most crashes with fatalities here have been straight out east over the bluff.

JP256 wrote:

ShadowAviator wrote:This talk is all foolishness.

The real secret to taking off in an underpowered bird is to stick your arm straight out the window and hold your hand at an angle. Works even better if your passenger does it, too.

Remember to shave your arms for less drag.

Even better if you can get them to flap their arm up and down synchronized exactly with yours... Of course, if they get out of phase, it's all for naught...

Also remember to cup your fingertips a bit that way you get that droop tip look.

A similarly inefficient technique is to climb at Vx or Vy as appropriate and begin a turn at 400' AGL. When pulling back, to continue climbing in this turn, results in descent or worse, upset may result.