Technique Details: Ultra Short Takeoff

[jamesbdunn]

I'm curious about what is needed to do ultra short takeoffs.

I see YouTube videos and different techniques used. At Valdez, a common technique is:

• Brakes On
• Full Power
• Elevator Brings Tail Level
• Looking Down the Runway (low AOA and minimized sail area)
• Release Brakes
• Long before Speed Registers, pull back the elevator to get high AOA
• plane pops off the ground, elevator almost goes back to neutral
• shortly thereafter the plane is at Vx

That is what I think I am seeing.

Two questions:

1. What am I missing? The details I'm missing, and the queues that indicate the details.
2. What HP, propeller, ... are needed to raise the tail at full power. I don't think I've ever seen anyone able to pick up the tail at full power with brakes set in real life.

[PapuaPilot]

What is required is a high power to weight, a light weight aircraft, the ability to achieve a high angle of attack on the ground (tall main gear) and a climb prop. The wing area and design are also factors. An aft CG would help too. After that it comes down to skill.

FYI my plane is able to lift the tail off the ground at full power with he brakes on. I did it last night with 5000' density altitude.

[StuBob]

Here's one way: https://youtu.be/dfXT38YIO6g

[southwind32]

Techniques will differ from plane to plane, and conditions, ie: surface conditions, slope, wind, etc etc.
In the 150hp super cub I use to own, the technique I used for the shortest takeoff roll was to hold brakes, stick back, full power, as soon as I released brakes the stick was smoothly brought forward to neutral, as soon as I felt the first indication of the tail coming up. I'd apply full flaps and at the same time slight back pressure to lift off. All this happened from brake release to flying in a couple seconds. I tried other techniques, such as lifting the tail, then releasing the brakes, but typically the tail would want to lower as the airplane began to roll. Nothing I tried could get the plane off sooner then the above technique. The down side is, if you're in rough conditions, you might be better to raise the tail sooner, so as to lessen the stress on the tailwheel. However in my plane and my experience that would result in a slightly longer takeoff roll. In any of the above scenarios you want to lower the nose right after lift off and stay in ground effect until a safe climb speed is attained.

[jamesbdunn]

Here's one way: https://youtu.be/dfXT38YIO6g

Very nice. Thank you. The series provides many pearls of useful insight.

[jamesbdunn]

southwind32: paraphrasing
is this correct?

Technique for the shortest takeoff roll:

1. hold brakes
2. stick back
3. full power
   
4. as soon as brakes released, stick smoothly brought forward to neutral
5. at the first indication of tail coming up, quickly apply full flaps and at the same time slight back pressure to lift off (flaps pitch forward, goal is to lift straight up)
6. while accelerating in ground effect, quickly bleed off flaps; the goal is to maintain stable ground clearance while accelerating (can be as short at a couple of seconds depending on aircraft configuration and conditions)
   
7. lower the nose right after lift off and stay in ground effect until a safe climb speed is attained

in rough conditions, raise the tail sooner, but this extends time to lift off