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I watch STOL pilot champs Zenith CH701 here. The engine power are: 130HP, 80HP, 120, and 100HP respectively. Amazing. As per my observation, the third airplane take off shorter than it length. It uses 120HP engine. I tried to search over the net how long is the required runway to make it take off, unfortunately I could not find. But I believe that should be longer than its length.

My question is, what the technical requirement to make an airplane can take off very short.

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  • $\begingroup$ Thrust, lift and light weight. $\endgroup$ – user3528438 Dec 12 '18 at 15:21
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There are a number of factors that can contribute to short take off landing (STOL) ability.

The Zenith page has some information: http://www.zenithair.com/stolch801/design/design.html

Wing Shape

A more "cupped" wing shape generates more lift at a slower speed, enabling a shorter take off. This sacrifices the aircraft's top speed. Note that this limitation can be mitigated by making the wing shape changeable with slats and flaps.

There are other modifications that can be made to a wing shape to favor STOL characteristics. For example, there are a variety of STOL kits that can be added to existing aircraft. These range from wing tips to other airfoil shape changes.

Wind Speed

By taking off into a higher speed wind, the takeoff distance is decreased. With a strong enough headwind (and a skilled pilot), a STOL aircraft and appear to take off vertically with little or no runway needed.

Power to Weight Ratio

The more powerful the engine is compared to the weight of the overall aircraft, the less runway is required to achieve takeoff speed.

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  • $\begingroup$ @RonBeyer - I agree that the wording is off... Will update. $\endgroup$ – RQDQ Dec 12 '18 at 14:35
  • $\begingroup$ Might want to add wing loading -- combine low wing loading with high lift devices and you can take off slower, hence shorter. $\endgroup$ – Zeiss Ikon Dec 12 '18 at 15:16
  • $\begingroup$ Also drag. High drag will slow acceleration and increase take-off run (although in most cases high drag is a by-product of high lift, which reduces take-off run) $\endgroup$ – DJClayworth Dec 12 '18 at 15:32
  • $\begingroup$ Thank you @RQDQ for the nice explanation. $\endgroup$ – AirCraft Lover Dec 13 '18 at 1:53
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Those STOL (not VTOL) planes have wings with high-lift devices as large flaps and slats, that greatly increase the lift coefficient, thus allowing the plane to take off with relatively little airspeed. Besides, in the video, the takeoff runs are greatly favored by a stiff headwind...

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  • $\begingroup$ Yes my friend, apologize for the error. I have corrected it to STOL. Another comment I have to read several time to make me really understand. $\endgroup$ – AirCraft Lover Dec 12 '18 at 14:48
  • $\begingroup$ I found some interesting things here: large flaps and slats, that greatly increase the lift coefficient, thus allowing the plane to take off with relatively little airspeed, and stiff headwind. I have to study them so I can comment further as they are quite new for me. $\endgroup$ – AirCraft Lover Dec 13 '18 at 1:13
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The planes had high-lift wings - nice thick wing, and with flaperons at the trailing edge to make the wing seem wider (front to back) to create more lift. Lightly loaded, just single passenger, and it also was quite a windy day, so they weren't depending on just engine horsepower to create airspeed over the wing - witness the 4th landing, where the plane was blown sideways and then backwards and the tail blown up in the air and up on its nose.

And of course practice.

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  • $\begingroup$ Any plane, under any wind conditions, depends exclusively on engine power in order to generate airspeed. $\endgroup$ – xxavier Dec 12 '18 at 17:42
  • $\begingroup$ Seems, pilot skill was more contributing in that champ. He can take off and landing very short. Another factor are important, but in this case, as there was another higher horse power where the design are same, so the more contributing thing is the pilot skill. $\endgroup$ – AirCraft Lover Dec 13 '18 at 1:56

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