High altitude airports

MAKG1 said:
Not every CA airport is at sea level. There are several in the Sierra that require mountain techniques, some of them with not-so-long runways. There are quite a few that require moderate DA techniques in summer.
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I'd add that, in terms of mountain flying, some of the Sierra terrain is far more rugged than the Colorado Rockies. I recall doing a dual flight from KAPA to Leadville for a Califirmia visitor who remarked how many obvious emergency landing sites we had along our route compared with back home.

It is also a mistake to automatically associate mountain flying with super high density altitude. Density altitude is about aircraft performance and applies just as much in the flatlands of Denver as it dies in the mountains to the west.

Mountain flying primarily has to do with two things. Relative terrain height and the effect of terrain on the flow of wind and weather. One needs to consider circling to gain altitude when departing a number of airports in the eastern ranges, and the winds and weather at Mt Washington in NH is considered by some to at times be the worst in the country despite being "underground" by Colorado standards.
 
True enough. I saw a helluva rotor cloud over the Peninsula about two weeks ago. I didn't fly that day....
 
Here's a fun one.

Alpine County (5,800 ft MSL) is one of those that I flew in to a few times during my mountain checkout. It's not short (4,400 ft) but it's no South Lake Tahoe either, so it can be a challenge when the DA is pushing 10,000 feet. It's carved in to the side of a mountain. Undershooting or overshooting it would be a real bad thing.
 
I'm used to about 6,000' MSL and I think it takes about 4,000' MSL to really notice the increase in performance, so you probably won't feel much of a decrease in 1,000', unless you're in a truly under powered aircraft.
 
rachelk.tailwinds said:
I'm used to about 6,000' MSL and I think it takes about 4,000' MSL to really notice the increase in performance, so you probably won't feel much of a decrease in 1,000', unless you're in a truly under powered aircraft.
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Actually, you can feel the difference between a hot and cold day at the same altitude, very easily. At high altitude airports, it can make the difference between flying and not flying. At lower airports, it won't unless you're overloaded (which is way more common than it should be) or the winds are scary. But the climb rate will be noticeably lower.

You'll study density altitude at some point during your training.

4000 MSL at -20 C will have a density altitude near sea level. At +35 C, it will be 7000 or so.
 
Thanks guys---the plane and I survived the "mountains" so perhaps I was more concerned than need be. I am aware that each A/C has its own limits and manufacturer recommendations but was more curious to see at which airport height persons changed their thought processes. For instance---the slow mobile is a Cherokee 140 and I have most of my hours in a 172 so now I am having to remember that lost HP also means lost performance ability.

As with all training---what you experience during training and after can be different. For instance--all during my IR training I never was issued a DP and we never went somewhere that had one. Now a year later I've been issued DP's my last two flights. Always learning and improving :)
 
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A few thousand MSL will be easily doable in those aircraft, unless it's stupid-hot. Then, you won't want to fly in a PA28 at all.

I wouldn't take a PA28 above 10,000, even with 180 HP let alone 140, unless it's turbocharged. BTDT in a Warrior, and you have to be real light and the winds dead calm to get better than scary performance.

The PA28 POH is rather vague on leaning for takeoff. It says to "set" the mixture, and that's it. When in doubt, full power run-up leaned for max RPM, whenever above 5000 feet DA, and "half leaned" above 3000. A 172 should be leaned at run-up (full power if any doubt) for max RPM above 3000.

The PA28 POH says that full rich can be used when you don't know if you're above 75% power or not, and separately that you can't be above 75% power above 5000 feet. I don't agree about using full rich at medium altitudes. Aggressive leaning may cause detonation, but full rich at 3000+ DA yields obviously suboptimal climbs.
 
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MAKG1 said:
Actually, you can feel the difference between a hot and cold day at the same altitude, very easily. At high altitude airports, it can make the difference between flying and not flying. At lower airports, it won't unless you're overloaded (which is way more common than it should be) or the winds are scary. But the climb rate will be noticeably lower.

You'll study density altitude at some point during your training.

4000 MSL at -20 C will have a density altitude near sea level. At +35 C, it will be 7000 or so.
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Oh yeah, big time. But I think the performance quality at different density altitudes is easier to identify when you're at your home airport because you're used to the runway width and length and the ground references when you're at certain altitudes. But for me, to be at an unfamiliar airport, it takes that much altitude for the plane to feel faster.

For example, I'm at KFTG one day when the density altitude is 5,500' and I'm turning crosswind at 300' just at the end of the runway. The next day I go out, the density altitude is 6,500' and I'm turning crosswind much further down. It is obvious to see the difference when you have all of the same factors and visual references around you.

But let's say you're flying from KFTG to KRKS on the same day in the same atmospheric conditions. The variance in performance is nothing to shake a stick at. You change your mixture a little and that's about all you actually feel.
 
rachelk.tailwinds said:
Oh yeah, big time. But I think the performance quality at different density altitudes is easier to identify when you're at your home airport because you're used to the runway width and length and the ground references when you're at certain altitudes. But for me, to be at an unfarmilliar airport, it takes that much altitued for the plane to feel faster.

For example, I'm at KFTG one day when the density altitued is 5,500' and I'm turning crosswind at 300' just at the end of the runway. The next day I go out, the density altitude is 6,500' and I'm turning crosswind much further down. It is obvious to see the difference when you have all of the same factors around you.

But let's say you're flying from KFTG to KRKS on the same day in the same atmospheric conditions. The variance in performance is nothing to shake a stick at. You change your mixture a little and that's about all you actually feel.
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Yes, but the OP is asking about lower altitudes, where the question is whether or not to lean for takeoff. At 3000 MSL on a cold day, you shouldn't. At sea level on a really hot day, you should. You have to do the DA calculation and make the decision based on that. And it can change from one hour to the next, by a lot more than 1000 feet in a bad case.

Believe me, you notice it at a big Class C airport at 400 MSL when you take off full rich in a 182 and it climbs like a sick Warrior. Even when you had never been there before.
 
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I would think of it more as performance margin than just elevation or even DA, although both of those are factors. Runway length and surrounding terrain are just as critical.

For example, KAPA in Denver is 5800', sure, but it has a 10,001' runway! That is a ****ton of margin for almost any airplane even when DA is up around 10,000'. It's also in the flat lands. If you can muster 200 fpm you're fine.

Heck even Leadville has a >6,000' runway and actually is situated in a valley with falling terrain. Even though it is the highest airport in North America people take off with plenty of runway to spare and level out over the valley to gain speed and altitude all the time. It is just about performance margin and having a plan for the nearby terrain.

There are short runways at much lower elevations and runways with rising terrain around them that pucker me up more because my margins are thinner than I'm comfortable with.

Learn to consider many factors... loading, leaning, runway length, runway DA, obstacle and terrain clearance.
 
rachelk.tailwinds said:
Oh yeah, big time. But I think the performance quality at different density altitudes is easier to identify when you're at your home airport because you're used to the runway width and length and the ground references when you're at certain altitudes. But for me, to be at an unfamiliar airport, it takes that much altitude for the plane to feel faster.

For example, I'm at KFTG one day when the density altitude is 5,500' and I'm turning crosswind at 300' just at the end of the runway. The next day I go out, the density altitude is 6,500' and I'm turning crosswind much further down. It is obvious to see the difference when you have all of the same factors and visual references around you.

But let's say you're flying from KFTG to KRKS on the same day in the same atmospheric conditions. The variance in performance is nothing to shake a stick at. You change your mixture a little and that's about all you actually feel.
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Part of not feeling it is also familiarity with the process. Flying at Front Range one starts dealing with density altitude as a practical part of flying as a student pilot and deals with it every single time you get into an airplane.

Making adjustments for the variations that accompany changes in density altitude is as natural and quasi-automatic as dealing with a 10 KT headwind on final as opposed to a calm day. It's such a basic part of your flying that it is barely noticeable. But take a pilot who has always landed in calm winds and that simple 10 KT headwind might throw them.
 
Anymouse said:
I remember watching that movie!
Highest elevation field I ever flew from was a bit more than 8k MSL.

https://en.wikipedia.org/wiki/Bamyan_Airport

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Actually, there might be one or two higher that I've flown from. This was the most scenic though.
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I have landed at Leadville and Telluride but the scenery wasn't quite the same as in your pics...
 
I live in Reno so field elevation is 4415'. I am never running full rich here. Anything over 6000' I consider high.
 
rachelk.tailwinds said:
Oh yeah, big time. But I think the performance quality at different density altitudes is easier to identify when you're at your home airport because you're used to the runway width and length and the ground references when you're at certain altitudes. But for me, to be at an unfamiliar airport, it takes that much altitude for the plane to feel faster.

For example, I'm at KFTG one day when the density altitude is 5,500' and I'm turning crosswind at 300' just at the end of the runway. The next day I go out, the density altitude is 6,500' and I'm turning crosswind much further down. It is obvious to see the difference when you have all of the same factors and visual references around you.

But let's say you're flying from KFTG to KRKS on the same day in the same atmospheric conditions. The variance in performance is nothing to shake a stick at. You change your mixture a little and that's about all you actually feel.
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The ONLY reason to visit Rock Springs Wy is to witness what we call a "light breeze".. Usually 35, gusting to 60...:yikes:......:D
 
N801BH said:
The ONLY reason to visit Rock Springs Wy is to witness what we call a "light breeze".. Usually 35, gusting to 60...:yikes:......:D
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Hahaha you know that you mention it, I do remember it being incredibly windy when I was there!
 
MAKG1 said:
I wouldn't take a PA28 above 10,000, even with 180 HP let alone 140, unless it's turbocharged. BTDT in a Warrior, and you have to be real light and the winds dead calm to get better than scary performance.
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I fly my PA28-236 at 11,500 almost every time I fly. It is certainly not turbocharged.
 
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