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Can the tail get too high?

I actually measured takeoff distances with various techniques. With the J-3 and Super Cub I could not measure a difference.

With the C-180, by the time you get the tail off the ground, a three point takeoff would have had you airborne. It is dramatic.

With low powered Champs and at least the UPF-7, you may want to raise the tail a bit to avoid lifting off too soon. The Cub is controllable well below stall speeds, so I find it better to lift off early. In a Cub, I just relax the back pressure and let it fly off.

Most of my students with prior taildragger experience hav never - ever - done a takeoff from a 3-point attitude. I have seen 180 drivers lower the flaps for takeoff, then get it up on the mains until 70 indicated, then climb out at 90 with flaps extended until 1000' agl. They say it climbs faster that way. The laws of basic physics do not back that up.
 
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aktango58 is correct when he says “Every aircraft is different.”


Congratulations on building and flying a SQ2. It’s roots are Super Cub but it’s design is highly modified making it a unique aircraft to fly. I haven’t seen yours so can’t speak to its exact design but I can speak of mine.


Its tail feathers are bigger then a Super Cub so have more authority. The flaps are double-slotted fowlers that extend to 62 degrees where they both can blank out the elevators fairly effectively while at the same time trapping air under the wing to such an extent that the tail will lift under the right circumstances. I’ll leave it up to you to imagine what can happen if allowed.


Stay off the payment as much as possible, it has nothing to teach you and can delay your becoming comfortable on turf and off-airport (land pavement just enough to stay proficient and not fear it). Wheel landings are a very important part of off-airport flying but running down a runway pinning the plane on the ground teaches nothing.


Instead find a long, unobstructed grass strip or better yet a beach, long sand or gravel bars. Set up to land, then as soon as the mains are on pick up just enough speed to fly the tail, not enough to fly the plane. Wheel along for a bit then add just enough power to get airborne, back off on the power to land, add just enough power to fly the tail, wheel along for a bit and then back in the air and repeat the process. A few thousand times should be sufficient. ;-)


An added bonus you will be gaining a greater understanding of just when the plane can fly and when it can’t which will help you become very precise to where your wheels touchdown and lift off.


IMPORTANT: Don’t land on surfaces you are unfamiliar with, especially sand.

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I’m very fortunate to have an area close by here in Texas where I can do this for probably 10 to 15 minutes at a time. There are wires and fences I have to avoid. Here is a video that illustrates what I’m talking about (you may have seen it before):

Have fun!



https://vimeo.com/160424468
 

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Bob, we've tried takeoff in an O-200 powered J3 vs a 160 hp SuperCub.
165 pound pilots, identical payload (light), on grass, 70°F, 8 kt wind straight down the runway.
J3 avg 65-75 feet
PA18 avg 190-200 feet.
The J3 was about 25 feet in the air when the 18 broke ground.
Some of that was pilot technique.
 
Bob, we've tried takeoff in an O-200 powered J3 vs a 160 hp SuperCub.
165 pound pilots, identical payload (light), on grass, 70°F, 8 kt wind straight down the runway.
J3 avg 65-75 feet
PA18 avg 190-200 feet.
The J3 was about 25 feet in the air when the 18 broke ground.
Some of that was pilot technique.

I did the same years ago - my 150 hp PA-12 and my friend's 90 HP J3 side by side on firm, sandy beach. Dead even.
 
Bob, we've tried takeoff in an O-200 powered J3 vs a 160 hp SuperCub.
165 pound pilots, identical payload (light), on grass, 70°F, 8 kt wind straight down the runway.
J3 avg 65-75 feet
PA18 avg 190-200 feet.
The J3 was about 25 feet in the air when the 18 broke ground.
Some of that was pilot technique.

Some?????
 
After reading all the responses to this thread which is named "can the tail get too high" my answer is yes. The tail is too high when the prop strikes the ground.
 
I was riding in the back seat of a 7GCBC one time when the owner/pilot decided to practice a wheel landing. From where I was sitting it seemed to be at the proper attitude, yet we both heard a small ting, ting, ting from forward of the engine. Fortunately the damage was minor, but the prop did touch the pavement.

Trying to hold an airplane on the ground beyond normal flying speed can only lead to eventual trouble. As the speed builds, the lift on the wing builds, the stick has to be pushed further forward etc., etc. Eventually the prop starts to turn green (if on grass). This maneuver proves nothing beyond the entertainment factor. If your airplane is heavily loaded sometimes it is important to accelerate to a higher than normal speed in order to be able to climb out of ground effect. Of course this depends on what type of airplane we are talking about. Personally I like to get the tail just above the ground letting the plane fly off when it is ready for normal take offs.
 
My elevator has never had the authority to lift the tail enough to create a problem. Go lift your tail high enough to threaten prop-ground contact and you'll see why. My new plane will use an 86" prop but maintaining "normal" prop clearance is in my best interest.

§ 23.925 Propeller clearance.Unless smaller clearances are substantiated, propeller clearances, with the airplane at the most adverse combination of weight and center of gravity, and with the propeller in the most adverse pitch position, may not be less than the following:
(a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically deflected and in the level, normal takeoff, or taxing attitude, whichever is most critical. In addition, for each airplane with conventional landing gear struts using fluid or mechanical means for absorbing landing shocks, there must be positive clearance between the propeller and the ground in the level takeoff attitude with the critical tire completely deflated and the corresponding landing gear strut bottomed. Positive clearance for airplanes using leaf spring struts is shown with a deflection corresponding to 1.5g.
(b) Aft-mounted propellers. In addition to the clearances specified in paragraph (a) of this section, an airplane with an aft mounted propeller must be designed such that the propeller will not contact the runway surface when the airplane is in the maximum pitch attitude attainable during normal takeoffs and landings.
(c) Water clearance. There must be a clearance of at least 18 inches between each propeller and the water, unless compliance with § 23.239 can be shown with a lesser clearance.
(d) Structural clearance. There must be—
(1) At least one inch radial clearance between the blade tips and the airplane structure, plus any additional radial clearance necessary to prevent harmful vibration;
(2) At least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts of the airplane; and
(3) Positive clearance between other rotating parts of the propeller or spinner and stationary parts of the airplane.

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-43, 58 FR 18971, Apr. 9, 1993; Amdt. 23-51, 61 FR 5136, Feb. 9, 1996; Amdt. 23-48, 61 FR 5148, Feb. 9, 1996]
 
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