David Reid etc.

My final post is this. I do have two Bobcats, the first with 100 flights on it which, I think, may count as some real world experience, and I like them so much I don't want to lose them, period. Some aircraft HAVE been lost and I would like to get to the bottom of it, no more, no less. The only real answer is to put the thing in a wind tunnel and MEASURE the loads. However, someone far more qualified than I has done the calculations to see if there COULD be an elevator problem and the results of this work are available free to anyone who wants them, his employer paid him well for his work, he did this as an intellectual exercise, in the hope that he could shed some light on the problem for us and for which he asked for no return.

When a fullsize aircraft is lost the accident is investigated in very great detail, there is rarely a single cause, but usually a primary cause and contributory factors. What is not know for CERTAIN is why BCs have been lost, or if indeed there is ANY common cause. What can be easily done is to install more powerful servos and if the problem continues then we must look elsewhere but at least one obvious gap has been plugged.


There is a most interesting parrallel in the US at the moment. The Learjet 45 is currently grounded after one aircraft suffered a brittle fracture of the horizontal stab. actuator screw (HSAS) a failure which occurred on just one aircraft long after the certification process. The FAA has grounded the entire fleet at enormous cost to the operators and Bombardier, the manufacturer. The fleet remains grounded until a new spec. HSAS has been manufactured and fitted. A new actuator was manufactured after the first failure but the FAA are not entirely satisfied with its manufacture, so the Lear 45 is grounded until further notice. ( source : Flight International). I am most certainly not suggesting the Bobcat be grounded but just illustrating the way in which the FAA approaches control system problems.

Whilst BCs are not man- carrying they can, like any other model jet, cause serious injury or death if they are out of control with reduced pitch control so I think the problem should be identified if at all possible in the best interest of the manufacturer, operator and third parties.

Whatever anyone may say, I believe I have done my bit to identify the problem and, if nothing else, builders and operators may now take very close notice on installation and geometry and make sure that there are no errors there.

I have nothing more to offer.

Regards,

David Gladwin