Aerobatic Aircraft.... Misc. Ramblings
Walter Extra was kind enough to produce a purpose built aerobatic airplane that resembles a carbon tubed purpose built race car. The plane consists of a tubular frame fuselage with carbon honeycomb wings and a nice big 540 cubic inch 300 horsepower engine on the front. The plane is stressed for +/- 10 Gs single occupant which means, like the ChampCar, armatures are unlikely to exceed the plane's potential.
To fly one, the FAA requires you to have a private pilot's certificate, a tail wheel endorsement in your log book and a high performance endorsement in your log book. The tail wheel endorsement is a matter of spending some ground and flight time with an instructor discussing the characteristics of conventional (tail wheel) aircraft then building the skills necessary to fly tail wheel aircraft. Unlike tricycle gear planes, the drama is not over until you tie the plane down. Roll out after landing can be entertaining and taxing can be downright fun in a good wind. The high performance endorsement is a similar process involving ground and flight training on the nature of high performance (defined as over 200 horsepower engines) and, in the case of the Extra, constant speed propellers. The constant speed propeller concept is simple in that you have a governor that uses oil pressure to vary blade pitch to maintain a pilot set RPM. Using one adds managing propeller/engine speed to the task of flying the plane and requires adherence to the idea of controlling cylinder pressures when making power changes. The key is to lesson engine loading prior to reducing engine RPM and increase engine RPM before increasing engine loading. Going up on RPM means propeller first then set throttle (via manifold pressure) and going down means reduce throttle then reduce RPM.
To fly one safely, most anyone you speak to will strongly advise a check out with a qualified instructor. I am handling my check out in two distinct segments. The first segment was a normal class sign off to make sure I was safe in the aircraft in non-aerobatic flight. I learned to fly in conventional aircraft so my normal class work consisted of hours in the pattern doing touch and goes. These planes sink like a rock when you pull back the power and that takes a bit of getting used to. The second segment is doing the aerobatic work starting with spin and upset recovery. You have to know how to get yourself out of a botched maneuver before you can practice on your own. The work has progressed to loops, rolls, accelerated stalls, hammerheads, inverted turns and on and on.....
I was out doing some accelerated stalls with a friend and let him try one. Here is what happens when you have way too much rudder when it breaks, or in this case SNAPS. Here is what it looks like at 1/8 the speed.
200 Hour Update... I'm just approaching 200 hours in the Extra and am in the process of building an MX2. Most of the Extra time is in 40 minute hops out to the aerobatic area four or five times a week. There is always something new to learn.