I will ad this about aileron weight, except it applies to the elevator weight. Burt Rutan years ago issued the closest thing to an AD for the Varieze and Longeze about making the canard elevators to the correct weight, due to two aircraft experiencing flutter and the elevator disintegrating in flight causing the two planes to crash with no survivors, with heavy elevators. I am not trying to be gross, just reinforce the importance of building properly, and taking your time to get it right, if necessary like Mark L. and make some parts 3 and 4 times.
To bring this closer to home, my particular plane had a flutter of the elevator when using the belly board above 90 mph, or more than 50 degrees activation, according to the original builder. He had learned to fly around it, by not using the board until slower etc... Well this did not sit well with me so I went looking. Like Brian, I too found a BIG discrepancy with the controls of the elevator. It seems the cables were apparently different lengths, so that at full aft actuation, one cable went partially slack, while full forward both were tight. Having had my fair share of trainers that had seen more than enough hours, and been able to rotate the yoke 10 to 15 degrees each way without aileron deflection, but had been signed off as acceptable, and had two separate occurrences of having to fly two airplanes back to the airport with broken/runaway trim systems, I decided on my airplane I would limit the use of cables. I installed dual sticks bought from Brian (thank you) and pushtube direct to the elevator. I left cables on the ailerons and rudder, figuring if I lost one of them, I could use the other to fly around the problem to get back down and repair, but that there was no substitute for the elevator, and most KR owner/pilots had commented that it was hard if not impossible to fly the KR safely with just trim. The system I built is over built yes, but I have complete faith in it, and the DAR complemented on the system, saying I could not be too careful with that part of the control system (within reason of course). Netters that have been here awhile will also remember that I asked and received alot of guidance from Larry Flesner, and Dan Heath on the problem I had with my ailerons not being synchronized. The right wing actuated 30 degrees up and only 5 degrees down, while the left wing 5 degrees up and 15 down. Those cables were also off and needed balancing in length. Once they were adjusted properly, I then found that I was not getting 20 up and 10 down as prescribed. By changing the push tubes to a correct length one that was also operating in a flat plane as suggested by Dan, and by re-drilling the bellcrank as Larry suggested, I was able to get the proper actuation. My bet is that either or both of these conditions could have led to flutter if I had not corrected them during my refit. The elevator did flutter at a very low speed, and the original owner was very lucky not to have the plane break up in flight (maybe the slower speed helped with that at 100 mph). Hope this helps some builders at this stage or later on their building/inspections... Colin Rainey brokerpi...@bellsouth.net
