To Joe Pilot:
It has occurred to me that you obviously love Robinson Helicopters and you will defend them to your death. That is an admirable characteristic but it seems that you are carrying it to extremes.
I know what you are thinking, “Look who’s talking”. The only point of my writing the report was to bring to the attention of the NTSB that they had not considered all of the factors in their final report. That report in case you are interested is titled SPECIAL INVESTIGATION REPORT:
ROBINSON HELICOPTER COMPANY R22 LOSS OF MAIN ROTOR CONTROL ACCIDENTS. The number of the report is PB96-917003 NTSB/SIR-96/03. In the report they overlooked the problems involved in the certification and the testing in order to gain certification. They did not look into the rotor head design and they did not look into the rigging procedure. It seems to me that the NTSB has seen the light although you haven’t as they are going to reopen their investigation on the basis of the report.
Your comment 3) It is also obvious that you have access to a very good engineering library as it seems you copied a textbook for the definition of fatigue. My point was that the mast and rotor system could develop fractures and or excessive wear due to the high flapping loads and /or the tendency for the blades to lead and lag. These loads are reacted by the through bolt (Teeter Bolt) and the rotor and the mast. The mast is subject to a cyclical twisting at twice the frequency of main rotor rotation and the holes that the teeter bolt passes through are subject to elongation due to the high frequency twisting loads. The mast fractures when the applied load exceeds the yield strength of the mast or, if the long-standing cyclic twisting loads and the high flapping loads cause a weakening of the metallic matrix of the mast.
Your comment 4) I would strongly suggest you keep your insurance up to date. As they say, Fate is the hunter. Another point made by you or one of the other contributors about lawyers being asses. They may seem that way to you but not to the families if you or any one else eats it in a crash. Lawyers like pilots and engineers have their place in society.
Your comment 1) Ask your engineers if they can make a comparison between the Robinson rigging procedure and say a bell or a Sikorsky. If they can’t give you a satisfactory answer, ask them if they have ever worked on a Bell or Sikorsky. There is a saying in computers called WYSISWYG or, What You See Is What You Get. This is not so on the rigging procedure for the Robinson. Rigging for low pitch and for cyclic pitch requires that the blades be oriented as if you were rigging a Bell helicopter. Over the nose and tail or, over the lateral axis. When the pitch setting is made the blade may be over the longitudinal or lateral axis but the pitch link is not.
When the pitch is set in the blades by adjusting the pitch links or the PP tubes the blade will increase in pitch or decrease in pitch when the pitch link is over the longitudinal or lateral axis. This is because of the 18 degree offset. That is what I meant by saying that you could rig too much pitch. Another point regarding rigging that you have overlooked and that is, if the cyclic is placed in the neutral position fore and aft how do you explain that the pitch angles are different when you move the stick to the forward stop and when you move the cyclic against the rear stop.
They should be the same, but the Robbo rigging procedure states that they must be different and if they are the same the mechanic must adjust PP tubes to get the desired reading. Please tell me why the Robbo is different from any other helicopter
Your comment 5) Regarding spool up I was only referring to a previous statement made by another individual.
Your comment 6) The Ferrari analogy had nothing to do with power. My point was that if you put the Holden engine in a Ferrari you would seriously effect its’ overall performance. By placing the restrictions on the Robbo you seriously effected its’ performance. It seems however that you don’t let the restrictions get in your way as you are flying the R22 outside of the FAA mandated restrictions regarding sideslip and out of trim. Like you said on several occasions, it is up to the pilot as to how he wants to fly or, if he wants to fly his machine into a mountain.
It seems that no matter how hard I try, I will never win this argument. So, just keep loving the Robbos’ and for your families’ sake, keep up your insurance.
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The Cat