Ed, I'm afraid I don't get the logic of your first paragraph. A tail dragger is not designed for any optimal take off angle from the three point attitude. A tail dagger is designed as a tail dragger mainly because it is easier to design and cheaper to build. They also are better suited for unimproved fields because you can get the tail wheel off the ground faster than a nose wheel. You do not take of in a tail dragger with the tail wheel on the ground. You have to lift the tail and accelerate and then rotate. And just like in a nose wheel airplane if you do it too soon you risk flopping back down.
Kevin1 --- In [email protected], "Ed Burkhead" <e...@...> wrote: > > > Daniel Arditi wrote: > > For those who got accustomed in taking off and landing > > with a "low tail" (especially during take off): Did you have > > any problem or something to tell about the difference? > > > > I once heard that after rising the tail, and on a short grass > > field the pilot had to abort a take off because he felt > > uncomfortable as it was a bit hard to rotate in that same > > field as he used to operate ? > > Daniel, > > Tail dragger aircraft drag their tails on the ground largely because that > angle of attack is about right for absolute minimum speed liftoff. In > other words, according to Wolfgang Langewiesche, author of ¡°Stick and > Rudder,¡± a tail dragger gear (called the ¡°conventional¡± gear in antique > days) is really a ¡°takeoff¡± gear. > > A Coupe with a tail low condition is rolling down the runway part-way to > being a taildragger and could, conceivably, lift off sooner than a properly > rigged Coupe - as long as the crosswind is mild, otherwise the plane is in > danger. > > When you lift off at that minimum airspeed, you have little reserve lift > and a lull in the wind could drop you back to the runway in a bad way. > > Over many years, I was able to operate comfortably out of 1800 ft. grass > runways (with no obstacles) and would sometimes accept a 1600 ft. grass > runway if conditions were right. I found this in the worst configuration, > 1400 pounds gross weight and tail at the normal height on a plane rigged > with the 9¢ª elevator up travel.: > > 1. The plane will pick up speed faster when it is level on the ground as > the wings are at a low angle of attack presenting their lowest parasitic > and induced drag. > > 2. When you are on a very short runway, as you get close to liftoff speed, > you can use the elevator to raise the nose, lift off a couple of feet, > lower the nose a bit and let the plane pick up speed in low ground effect. > In low ground effect, you have no rolling friction from the ground or grass > AND you have almost no induced drag as you are in close ground effect. So, > you quickly pick up the extra few mph you need for a safe climb out at best > angle or best rate of climb airspeed, your choice. This technique is > especially important on long grass, muddy or rough air fields. > > 3. If the runway is so short that having a tail low Coupe instead of a > correctly rigged Coupe makes a significant difference in safety, you do NOT > have enough safety margin to be operating out of that airfield. Get an > aggressive climb prop and/or a bigger engine and/or lighten you load > considerably so you can change to a different airfield. > > Ed > > Ed Burkhead > http://edburkhead/Ercoupe/index.htm > ed -at- edburkh???ead . com (change -at- to @ and remove ??? and > spaces) > _ >
