To Lu Z,
a. The original para (a) was that cyclic application and sideslip are separate issues. You seem to agree here. No question that sideslip will produce flapping loads. See para (b) for discussion on cyclic application, as I purposely separated these issu4es for discussion.
b. Yes, I have an argument here. I am not convinced that the application of cyclic causes high (if any) flapping loads. I am even more skeptical now that you have changed your position by saying it only occurs under zero G. The disc DOES NOT behave differently under zero G. How could it? You know I do not have the POH, so perhaps you could post the bit where it says that “The application of left cyclic only during zero G conditions will cause severe flapping loads”? P.S. Why is it that you quote the POH as an authority here, but your whole argument is that the POH is flawed?
c. Thank you for conceding that >> It is true that the disc does not behave wildly under a zero G condition<< but then you repeat the left cyclic equals flapping argument, and introduce an entirely new (and irrelevant word: frequency. Lets ignore frequency, and go back to the cyclic issue. Once again, please quote the POH, or explain why.
d. Your answer here once again ignores the fundamental question. Talking about which way the cyclic needs to be pushed to go forward is getting off track. Both the Robbie and the Bell teetering head share the same mast bump characteristics in zero G. One of them doesn’t use an 18 degree offset, nor conning hinges, but they both still behave the same way. How can this be other than the conning hinges and offset ARE IRRELEVANT? Did you know that the UH-1H and B205 A1 have tail rotors on opposite sides of the tail boom? This doesn’t affect zero G behaviour either – therefore it is irrelevant too! You know that the blade shape on the uh-1h and 205 A1 are different, but again it is irrelevant to the zero G situation. You need to be able to demonstrate a distinct difference attributable to a component before it can be RELEVANT. So far you have not done that with the conning hinges or offset. Until you can define a behavioural difference your argument is mute. So I ask once again: If a Bell system is vulnerable to mast bump in exactly the same circumstances as a Robbie, and it does NOT have the 18 degree offset, nor the flapping hinges – how can the 18 degree offset or flapping hinges be the culprit??????.
e. Great, you have the statistics on mast separations. Kind of prooves the point that the lack of 18 degree offset and conning hinges have not protected the Bell system doesn’t it?
f. roger that..
g. Lets keep “cyclic causes flapping” to (b). But I would still like your reply to the original questions which I have reproduced here: You then state that :>>If my contention of the 18-degree offset were correct then this would further exacerbate the problem by increasing the roll rate<< Interesting assertion Lu, how do you think the offset increases roll rate? Do you believe this always happens, or only with zero G? If only with zero G, how does the G affect the offset?