Quot from Lu:
This is for Helo Teacher:
The certification requirements state that any new helicopter design demonstrate sideslipping by hitting the pedals to the stop while flying at .6 VNE. It must also demonstrate out of trim flight by +/- 10 degrees. If the Robinson helicopters are now restricted from flying this way because to do so will increase the flapping loads to the point of mast bumping then how did they demonstrate that capability during certification with out beating the helicopter to death. That is the main point of my report. I stated that if the helicopter were put up for certification now, and could not demonstrate these certification requirements, then the FAA would tell them to piss off.
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The Cat
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Lu, you obviously didn't learn much about pilotage while you were in those helicopters long long ago, so I'll give a quick lesson.
Some basics:
ALL helicopters are designed to fly in trim.
An out of trim helicopter is less stable.
Inexperienced pilots react unpredictably.
I read the page in the manual, and I will try one more time to explain my point, try to listen this time. Out of trim flight is less stable, and the majority of R22 rotor-loss accidents are caused by overcontrolling. The tendency for low-time and inexperienced pilot who are sideslipping an R22 is to overcontrol in pitch. They quickly get into a condition of pilot-induced-oscillation (PIO) which can easily cause the mast bumping you are trying to pin on the design. They tend to do this alone because most instructors have a survival instinct. Telling the pilot that they SHOULD keep the aircraft in trim is common sense and keeps the inexperienced from killing themselves needlessly.
My point about the certification requirement, which went right past you, was that the act of demonstrating the capability to perform a maneuver doesn't necessarily make it normal. I've had students try many outrageous control inputs, and the R22/ Bell206, doesn't matter which, has so far always had the control authority to recover. That DOESN"T mean that I encourage them to try again. Now, how this relates to certification requirements:
For certification the manufacturer must demonstrate retreating blade tip stall, a condition which occurs above VNE. Does the more restrictive VNE invalidate the certification? NO! Is the VNE increased to this speed? NO! Does the demonstration of the capability, in the hands of a competent pilot, of the aircraft to fly out of trim make it a normal procedure? NO!
The recovery from low-G is not unique to R22's, its the same for any helo. I criticized your description about how to handle it because it made no sense. It is not flapping loads that cause mast contact in the low/0-g situation, it is the high flapping angles caused by a rotor disc not aligned with fuselage, usually induced by a scared pilot whose first instinct was wrong. And yes, hesitation is the wrong reaction.
I didn't want to get into this discussion but I'm getting tired of people maligning the aircraft because of misconceptions and prejudices. It is small and light. It is also responsive and tough. Too many people with too little experience will read what is here and believe it, so I gues Joe and I have to defend Frank's creation until gets off his duff and replies himself.
To helidvr: we have read that Frank will reply many times, no need to keep telling us until he does it. I have great respect for the man, but he is the king of CYA.
As an aside Lu, before you start attacking me as a brain-washed instructor who is defending the design on subconcious orders from Frank, let me say this. The R22 is a very economical helicopter and in the hands of an experienced pilot is a very effective tool. It found a place in the training schools because of low cost that allowed many pilot to get into helo flying. There are machines out there that are easier to teach in, and even preferable to teach in in some cases. Its touchy and unforgiving, and thats how people get into trouble.
With regard to the lawyers and their suits against Robinson, I have seen too many aviation lawsuits, especially from private pilots, that were so outrageous as to be laughable that have bankrupted very fine companies. Until the USA gains a little common sense in litigation, Frank is well advised to continue as he has to protect a company that is producing good machines at a reasonable price.