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Old 09-17-2008 | 10:51 PM
  #482  
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Craig-RCU
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From: minneapolis, MN
Default RE: GP GEE BEE

The Gee Bee is a handful to land. I haven't mastered it yet, but I think that I've got a better idea on how to tame this beast on landing after gaining some proficiency with a couple of my .60 size warbirds and a Great Planes Lancair ES. Great Planes tried to tame the take-off and landing characteristics of the Gee Bee with shorter than scale landing gear and lots of down and right thrust. This setup works great for take-off. The Gee Bee is easier to take off than my warbirds as it needs little to no rudder input to track straight down the runway and lift off gently as it accelerates. Experimenting with my warbirds, I found that they track straight as an arrow at speed with flaps up but porpoise like the Gee Bee when their flaps are down. I've learned to use this porpoising to my benefit on my warbirds as a way to judge airspeed. If I am set up on an approach and find that the plane wants to climb, I reduce throttle a bit and feed in a bit of down-elevator until the climbing tendency subsides. I'll know if I've reduced the throttle too much if the plane descends too steeply with my hands off elevator input. Basically, what is happening is that I'm using mostly throttle to control the descent rate instead of mostly elevator. Getting proficient at this required programming in some elevator trim when flaps were deployed to trim the model for landing speeds. I figured out how much elevator trim was needed for straight and level flight just above stall speed by taking the plane up a few mistakes high, deploying flaps, adjusting the elevator trim (counting the trim beeps so I could return the trim to normal after landing) until I found a safe landing speed just above the stall speed (If you try this, you should spend most of this flight getting used to the flight characteristics at this speed as a way to practice for landing, which no doubt will be flawless after having read this post ) After landing, I measured the difference in elevator trim between normal cruise to landing trim and programed that trim difference into the radio to be activated with my flaps switch. The Gee Bee doesn't have flaps, but the same process can be used to set the trim for landing speed. If you don't have a computer radio, you'll have to remember how many clicks of trim away from normal cruise speed are needed. If you do have a computer radio, you can program the landing trim to be activated with a two or three position switch or dial. Since the Gee Bee has an abrupt tip stall to the left, it may be a good idea to also add right rudder trim to the landing configuration trim settings. The proper right rudder trim can be found out at the same time that you are experimenting to find the proper elevator trim for landing.

The large amount of down thrust on the GB can throw a wrench into this process. You'll see my GB dive on the aborted landings on this video as I throttle up http://www.rcuvideos.com/video/gbstruts-wmv This is the effect of the down-thrust. I haven't figured out how to deal with this other than to be aware of it and compensate with elevator manually. My radio doesn't have the capability needed to mix this out. To mix this tendency out, it would be necessary to mix up elevator with full throttle but the up elevator mix is only needed until normal cruise speed is reached. Well, that is the best that I can figure out about how to tame landings for the GB. I haven't actually tried this approach with my GB, but I'd be happy to use you as a guinny pig if you think it's worth a shot