Thursday, April 22, 2010

Tailwheel Travails - Lessons Four & Five

I promised more on my ham-fisted attempts to learn to fly a tailwheel aircraft. It's been a while but here we are. In the meantime I've been flying tamer aircraft - ones with the third wheel on the other end. I've also been doing some time in the right hand seat which is fun. Just as an aside: as I understand it there is no "command" seat in the Australian regulations. You just have to be able to reach all required equipment from the seat you are in. But a big word of warning: some people find it relatively easy to fly from the right hand seat and others don't. So until you know and until you are confident in a range of conditions, don't try it without an instructor. I've done a bit now in a range of aircraft and I like it, but I still want more time with an instructor.
So to the tailwheel. This time we've been flying a slightly different version a Zlin Savage Cub, rather than the Classic we were flying before.
First lesson back was a brush up on 3 pointers and general handling, just getting my hand back in really. For those of you new to tailwheel flying the 3 pointer is where all three wheels land at the same time, it's sometimes called a "full stall" landing (though as Langewiesche points out it isn't necessarily stalled on landing). That's because you are doing what you would normally do in a nosewheel aircraft - holding off in a nose up attitude. With a tailwheel aircraft they are basically finished flying when they settle and they have very little tendency to want to bounce or start flying again. They're also generally flying quite slow. That means if anything goes a little squirrelly - as it can - it does so at a slow speed. That's kind of comforting.
The problem is that because you are going so slow you are a bit susceptible to crosswinds. You don't have the lateral control to stop the aircraft from weather-cocking into wind and you may also be a bit prone to wind shear - stopping flying before you planned to!
Langewiesche on this subject says: "The three point landing is not the only way to get an airplane down. It is not even the best way."
This is where the "wheel landing" comes in. The late Pip Borman once told me - in typically blunt Pip style - "If you can't do a wheel landing you can't fly a taildragger". So we moved on to wheelers.
How do you do a wheeler? Not to bore you with the mighty Langewiesche, but he says it better than me:
Coming in with a good deal of speed, break your glide so that the airplane shoots along level, half a foot or a foot above the ground. Then, when the spot arrives at which you want to make ground contact, simply push over forward and "plaster" the front wheels on. Then as you feel the ground, keep right on pressing forward on the stick so as to hold the ship on.
Sounds easy doesn't it? Well it is and it isn't. We started by choosing a higher approach speed and first stage of flaps. That means that the aircraft is in a high lift, modest drag configuration. We came in and did just as the master suggested - flew along level just above the ground using small amounts of thrust as necessary to keep the aircraft airborne. As we reached the end of the strip we powered up and went around. The idea was to learn to control the aircraft in the attitude in which it would land - a flying attitude, and to learn to visualise the actual height we wanted to fly at. It also gave us a chance to judge the inevitable 90 degree crosswind.
Having done that a couple of times we then came around for real. This time the idea was to minimise the sink rate and to kiss the ground. Unlike Langewiesche our idea was to let it settle and then to pin it by pushing the stick forward. The problem of course is that when you do a three pointer you progressively pole back to arrest the sink rate. You can't do that in a wheeler. So instead you have to very finely judge your height and very gently fly it on. That's counter-intuitive to all of us pilots who are used to flying tricycle gear.
So the inevitable happens - you bounce. Not much but you bounce. Here it's a case of just letting it settle again and getting that stick forward. With the stick properly forward, even though you have flying speed, the wing is at zero or negative lift angle of attack. It is "pinned" to the ground. You can get on the brakes quite hard and then slacken off as you slow down.
After a few of these the bounces got less and my judgement improved. Now it was time to go for a full flap wheeler. This meant that to keep the aircraft flying a fair bit of thrust was needed - we were behind the curve. So we came in with plenty of throttle and just held off the ground a few inches. Closing the throttle slightly allowed the aircraft to sink onto the ground and then I just poled forward to hold her there. You can use thrust at this point to maintain control and keep the tail up.
That's the thing about a wheeler, you can just keep pushing forward as the aircraft slows. You need to do that if you want to keep the tail up. As you slow you eventually lose elevator effectiveness the tail gently settles into a three point attitude.
These were fun landings. I really got a kick out of them and I can't wait to do a few more.
The other thing that's happened is that my tricycle undercarriage landings have improved as well. I reckon everyone should have to fly a 'dragger at some point in their training.
Note: Stick and Rudder: An explanation of the art of flying. Wolfgang Langewiesche, McGraw-Hill Inc, 1944, 1972. A book every pilot should read.

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