View Full Version : Main Wheel Position
jusplanenuts
08-05-2005, 08:48 AM
Not knowing a thing about gyro design, I have an elementary question concerning positioning of the main landing gear.
It seems they are typically positioned near the CG, and I've heard discussions about balancing on the main gear during take-off.
What would be the consequence of a having the wheels farther back, possibly also eliminating a tailwheel? :confused:
scottessex
08-05-2005, 08:55 AM
You'd take off tail first and have to learn to balance on the nose wheel, then you have to get real good at using the rudder pedals because the back end will be trying to catch the front. :p
Doug Riley
08-05-2005, 01:19 PM
Jeff: The Bensen 4-wheel gear is a great invention that actually pre-dates the Bensen gyro. It provides the advantages of taildragger gear without the disadvantages. The principal advantage is that it allows you the maximum possible angle of attack during both the latter part of the rotor spinup phase of your takeoff and the flare phase of your landing, with somewhat less mast height than you'd otherwise need. You should expect a longer takeoff roll (or need a full-RPM prerotator) if you move the mains back enough to eliminate the tailwheel.
At the same time, the auxiliary tail wheel will help pull any crab component out of your landing approach. It does this without presenting the ground instability of a conventional tailwheel rig.
Vance
08-05-2005, 01:36 PM
Hello Jeff, You might want to look at Ken Rehler's gyroplane. He doesn't have a tail wheel and it seems to work well. He has a very nice website attached to his public profile on this forum. Thank you, Vance
rehler
08-05-2005, 05:31 PM
Jeff,
There are several gyros with the main gear farther back and no tail wheels (usually have a skid just in case). My gyro is like that. It has twin rudders, so it has two skids. The skids have never touched the ground. The CG is slightly in front of the main wheels, just enough to keep the gyro sitting on the three wheels without a pilot in the seat, rather than tilting back on the tail wheel like most gyros do when the pilot gets out.
However, there is a good reason to have the main wheels closer to the CG. It makes takeoffs easier, allowing the pilot to "balance on the wheels", which is the flying attitude, so it simply lifts off in the same position when you add throttle. With the wheels back, like on mine, it is like a fixed wing (Cesna or Piper) takeoff where you pull back on the stick to lift off after you reach flying speed.
Been there done that !
I had the mains about 6" aft of the cog... it never did try to tilt to the tail wheel and the few hops I got out of it were short ( on purpose! ) and vertually a vertical lift ... no tilting forard or back at all ...
although the wind was the only reason I got a hop out of it in the first place it seamed quite controlable ....
However , under much consideration I was convinced to change the gyro's configuration one more time and get the thrust line down some
in the process I moved the Main landing gear foward to the mast wich is behind the cog by about 3 " the new configuration does indeed tilt back to the tail wheel now... this is important and not to be over looked because before you venture into the air you mist master the rudder control.... its not something thats realy simple ! it doesn't steer anything like the nose wheel ! this insight is because I have it able to tilt back to the tail wheel and I can steer with the rudder , where before I couldn't .... its an important safty /learning thing
...Personally I hate the look of my gyro setting with the nose wheel off the ground .... but its IMPORTANT !
for what its worth !
Bob....
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