To: Imlanphere
It is a well known fact that when a student graduates from a university, a technical school or say, a flight school he will have only that knowledge that was imparted to him by his instructors. If the student never expands on that knowledge he will only know what his instructors told him and nothing more.
Most helicopter flight schools start the student out in an R22. The instructors at that flight school may have been students at that same school only months before. Some of those instructors may have even attended a safety school at Robinson or at some field site where a Robinson Pilot taught the course. So, when one of the graduate students is asked a specific question he will provide an answer that fits the subject as he was taught. All Robinson helicopter pilots will respond in unison as if they were parroting the words as spoken by Frank Robinson.
First of all, the response that Frank Robinson made as quoted by you is totally false and this is why. Mr. Robinson mixed chickens and eggs so that you must really look at what he says in order to determine which came first.
The rotor head was designed from the very beginning as a teetering rotorhead with coning capability. Robinson knew from the beginning that the aerodynamics of a lightly loaded low inertia rotor would involve severe blade bending and blade flapping. In order to minimize those two negative actions they incorporated coning hinges.
Once coning hinges were installed they could never have a pitch horn that lead the blade by 90-degrees. To do so, would render the helicopter uncontrollable due to massive pitch coupling. By definition, the pitch horns could not pass the cone hinges. A 90-degree pitch horn would not force the pilot to compensate in the low speed regime. There would be no low speed or, for that matter high speed regime because when the pilot brought the helicopter to a hover, the pitch coupling would make it extremely difficult to maintain that hover and if he pushed forward cyclic the helicopter would most likely crash.
Robinsons’ theories, are fashioned to provide the neophyte pilot with information that the neophyte pilot believes to be true, and if that pilot never learns or accepts another alternate theory, then, when he is asked a question about a Robinson Helicopter, he will reply as if Robinson Helicopters signs his pay checks.
To: 212man
The reason that my posts are so diverse and I don’t address a particular point is because I have many interested individuals responding to the many points put forth in my report. Once I respond to a posting I get several more differing points of view that I in turn have to respond to. It is like playing a tennis match where I have 20-30 opponents at one time and they are all lobbing fuzzy yellow balls at me.
Regarding those statements that don’t show themselves in actual practice, I would refer you to those pilots that took up my challenge, and then reported back, that I was correct.
------------------
The Cat
[This message has been edited by Lu Zuckerman (edited 14 December 2000).]