PPRuNe Forums - View Single Post - Certification of Robinson Helicopters (incl post by Frank Robinson)
Old 24th Nov 2000, 20:03
  #149 (permalink)  
HeloTeacher
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Unhappy

When pulling into the hover, left cyclic is required to overcome tail rotor thrust. You hover with a left of center cyclic, now you know why the travel is more on the left.

The tail rotor is coupled very short in the R22, hence the high TR thrust in relation to weight.

You intiate forward flight with forward cyclic. The flapback that occurs with increasing speed is countered with increased forward cyclic, the disc and fuselage attitude DO NOT change, the additional forward cyclic is overcoming the flapback that results from the (momentary) dissymetry of lift.

We keep telling you about the reaction of the disc on the ground because that is the simplest reaction. In flight there are many more factors. A 20 degree cyclic offset would be very noticeable. It isn't there.

If theory is not supported by fact, amend the theory. That is what we have tried to explain to you.

I made the distinction between flapping angle and flapping load because the reason the rotor so easily gets out of control in a zero-G condition is the LACK OF LOAD! there is no pull from the mast to force the disc into any particular state, so it can float freely.

I have to wonder, are the questions in your report actually questions you want answered? We have answered many of them here!

1. I explained it above
2. there is no RFM restriction, but if you jerk the controls around at any time you are dead, be smooth. pull back and you slow down unless you jerk on the cyclic
3. mast-bumping, for exactly the same reason as if he tried to induce left roll
4. never. none. he'd roll roll right. ditto
5. relevance??
6. same as dihedral