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BJC

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As ugly it is in aesthetic and aerodynamic form Skyranger is, it is fully modular and easy to add new things - i would make Tailwind W10 styled wing tips / Or Strojnik version of them for skyranger if constantly need to operate in high altitude.
My comment had nothing to do with the aesthetics of the Skyranger.

Takeoff performance is not listed in the operator’s manual, but it does have this:


5.5 Takeoff performance
Take-off performance for short dry grass for your aircraft is contained in Annex A. Using those figures, the following additional safety factors should be applied to the distance to clear a 15metre obstacle (taken from CAA GA Safety Sense leaflet 7C).

Per 1000 ft runway height above Sea Level
Multiply by 1.1

Per 10°C increase in temperature above 15°C
Multiply by 1.1
Per 2% uphill slope
Multiply by 1.1
Soft ground or snow or wet grass

Multiply by 1.25+

If you have to take-off with a tailwind
Multiply by 1.2 for every 4 knots of wind

Now to be sure, multiply by 1.33, to take into account that you may not fly the aeroplane as well as the company test pilot did when he worked out the values in the manual.
The proposed runway is at 7,000 MSL.

Good luck.


BJC
 
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cluttonfred

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I think a light, long-wing Skyranger could manage that with a turbo-modded 912 and there are a number of companies offering complete engines or conversion kits of 120-150 hp or so. The issue for me is repeatability...sooner or later that kind of mountain flying is going to bite you, hard

Do you think that it could takeoff in 100m at 7,000' altitude?
 

Victor Bravo

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I think a light, long-wing Skyranger could manage that with a turbo-modded 912 and there are a number of companies offering complete engines or conversion kits of 120-150 hp or so. The issue for me is repeatability...sooner or later that kind of mountain flying is going to bite you, hard
I have never flown in South America, the Andes, etc. so anyone with that direct experience can feel free to correct me.

But if you will forgive the bloated ego for a moment, I do have a modest amount of partly relevant experience flying around in the Sierra Nevada mountains, in gusty high altitude conditions at fairly low speeds. All of that experience was while already airborne. We could always glide down to flatter ground to land, and the takeoffs were on the end of a tow rope :)

With that said - Take off and/or transitioning through the critical zero-airspeed to minimum flight speed phase, on a tiny little road like that, with gusty winds blowing across the ridgeline... I will bet dollars to Cotter Pins that ANY (fixed wing light GA) aircraft that is light and slow enough to operate in that environment in CALM conditions... will be WRECKED one out of three times you try to operate it in real-world gusty conditions in the environment shown in these photos.

I'm truly sorry to spoil anyone's daydreams of flying any sort of affordable "airplane" there. It's a delightful and beautiful daydream!

Steve Henry's Super-STOL - with Steve as required onboard equipment - is the closest possible thing, but I do believe even he would tell you that gusty winds blowing across that little ridge would make it a very high risk, even for him in his 300HP monster.
 

Starjumper7

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I want to let you guys know that I'm not planning on building or buying a plane this lifetime, OK? This is just some dream BS about what kind of plane 'could' possibly work at this location, and I know it's a tough one. No steenking Helio Courriers or anything like that. No flying station wagons.

To reiterate, this needs to be a small ultralight style plane but with a 'cheater' engine with a big geared prop for very steep climb angles. It needs to have a short wingspan to allow for a super fast roll rate, to deal with wind gusts, and avoid the trees encroaching at the sides of my airport =) In spite of the low wing span it needs to have a lot of wing area to allow floating or nearly parachute like descents.

The ridge top road was just a picture to show what it's like around here, but that is a bad place for a plane because, for example, today there is a powerful steady wind coming from the side and blowing across the ridge.

To help you see what I would be dealing with, I took a couple of pictures of my 'airport'. I paced it off and it is only like 36 meters/yards to the drop off at the north edge, rather than 100 like I imagined earlier. Also, at times there are horses standing around in the middle of the runway.

This is looking south, you can see it is not an acceptable take off direction due to the steep slope at that end. There's also the tree over on the left.AP2.JPG

This is looking north, which is the only possible takeoff direction. Taking off to the north, but landing to the south. The north end terminates in a big drop off into a ravine but it is facing the cliff wall which is not so far away, which you can see in the picture. Therefore taking off would require a sharp right turn, to the east, immediately after lifting off.
AP1.JPG

Landing would require approaching the north end of the runway from the east, from the right. There's big mountain walls over there too, so taking off would require a second right turn right away to the south to avoid that.
 
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Wayne

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As mentioned before - Paramotor on your cherished calm weather days. Closest thing to your mission that I’m personally aware of, and I know it’s not that close.
 

Dan Thomas

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Electric VTOL get full power at altitude if you want short range.
Takeoff runs would still be way longer simply because of the thin air. There's a considerable difference between indicated and true airspeeds up there. Wings and propellers need air, lots of it, and a 100m strip at 7000 feet isn't going to satisfy any practical fixed-wing I can think of. Especially on a warm day.

We regularly read of accidents at high-altitude airports in the US when people try to take off when the DA is too high. Even in turbocharged airplanes. At 7000 ASL the takeoff distance for a normally-aspirated airplane is about double the sea level distance, and the rate of climb is about half. And that's on pavement. Rough or grass would make the takeoff run worse.
 

Dan Thomas

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This is looking north, which is the only possible takeoff direction. Taking off the the north, but landing to the south. The north end terminates in a big drop off into a ravine but it is facing the cliff wall which is not so far away, which you can see in the picture. Therefore taking off would require a sharp right turn, to the east, immediately after lifting off.
Steep turns immediately after takeoff add a huge risk. A major load factor increase right when speed is minimal. Stalling and spinning would be the usual outcome.
 

BBerson

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Takeoff runs would still be way longer simply because of the thin air
That's why I said VTOL. A quad copter or helicopter made with extreme low disc loading can rise in the thin air on a calm day. The forward cruise would be limited to say 20 mph or something. The Mars helicopter flies in air 1% of Earth.
The other option is hot air airship. It works, but I think the slow rotorcraft is more user friendly.
 

Hephaestus

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Read that. Then go back to your first picture and pick out the lenticular and rotor clouds. Next calm day go release some helium balloons - after about 50' I bet they start dancing and not just floating straight up.

You will die in an ultralight in these conditions. Your altitude makes most of GA not workable. You really do need wing loading to penetrate these winds. Ultralight style light wing loadings - are for calm conditions only - you do not have calm conditions - even when you think you do.

I don't mean to be harsh but this is reality.

I did specifically say hang gliders for a reason - they really were developed to use this kind of ridge lift in the mountains.
 

Jay Dub

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I used to fly in the Andes in Bolivia. A few strips we serviced were around 14,500. Most all of our mountain strips were uphill/downhill and many of them were between 3000-5000' long and Gravel. Some of the strips you had to takeoff downhill even with 20 knots of wind at the tail. It was always interesting. The morning flights were usually easiest with the 3pm flights usually the most challenging.

I flew modified tu206 Cessnas with VGs, Robertson STOL kits, and intercoolers.

Looking at the photos, you don't have enough room at 7000'. Nor do you have any margin for safety whatsoever. I wouldn't recommend a light aircraft because the wind will blow you around terrible and possibly flip you over. The Andes are not very forgiving with wind nor terrain.
 

Starjumper7

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Steep turns immediately after takeoff add a huge risk. A major load factor increase right when speed is minimal. Stalling and spinning would be the usual outcome.
Yes I know about those things, that's why I mentioned a Zimmerman style flyer with extra power. I understand they do not stall or spin.

I agree with you guys in that this would be a pretty unsafe, or impossible, situation for any plane.

Someone mentioned gyrocopters. A gyro that can do a jump takeoff would be required, but how do those handle in turbulence?
 

BBerson

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Any rotorcraft should handle turbulence better than a fixed wing. But jump takeoff is rather rare, I think.
It isn't so much the chop turbulence, mountains have severe down drafts that can exceed your climb. Just can't out climb a strong downdraft. Down drafts are from the wind going down the back side. You can fly in the updraft on the first windward side. After that it all gets mixed. Best not to fly at all in the inner mountain wind. It isn't any fun.
 

Dana

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A very good pilot with one of the current crop of extreme bush planes (think Draco, or the planes you'll see at Valdez) could probably get in and out of there, but the penalty for screwing would be a lot worse than the kind of places most bush pilots are willing to attempt. Now depending on how much blasting you want to do...
 

Dana

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Someone mentioned gyrocopters. A gyro that can do a jump takeoff would be required, but how do those handle in turbulence?
That was my first thought, but with the severe turbulence you could get in a place like that, all you need is one downgust long enough to slow the rotor too much, and you're dead.
 

Hephaestus

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Yes I know about those things, that's why I mentioned a Zimmerman style flyer with extra power. I understand they do not stall or spin.
Zimmerman isn't going to help you - at sea level a zimmerman might parachute in a stall at a survivable rate of decent. At your altitude - that rate of descent isn't going to be survivable...

It all comes back to that altitude and location/weather.

I'm rarely one to say 'no good options' - all I can think of is hang gliders are out playing along the ridges when I cross the rockies. Maybe the powered trike style? But you'd probably need to make some compromises there too.
 

Victor Bravo

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One thing everybody else may have missed is that he just said he was not going to buy or build an aircraft in his lifetime. So the question is what is the purpose of the discussion?
 
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