Hi PTKay . I enjoy your input . Thanks.
I came across this report on the NSTB site .Maybe the FAA knows a bit more than we give them credit for.
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QUOTED FROM: From NSTB report:
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20020712X01113&key=1
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............The FAA's Rotorcraft Flying Handbook contains a discussion of pilot-induced oscillation (PIO), and power pushover situations.
The handbook notes that gyroplanes experience a slight delay between control input and the reaction of the aircraft. This
delay may cause an inexperienced pilot to apply more control input than required, resulting in a greater aircraft response
than was desired. Once the error has been recognized, opposite control input is applied to correct the flight attitude. Because
of the nature of the delay in aircraft response, it is possible for the corrections to be out of synchronization with the movements
of the aircraft and aggravate the undesired changes in attitude. The result is pilot-induced oscillations that can grow rapidly in
magnitude. A power pushover, as described in the FAA handbook, may result if rotor force is rapidly removed, producing a
tendency to pitch forward abruptly. This is often referred to as a forward tumble, buntover, or power pushover. Removing the
rotor force is often referred to as unloading the rotor, and can occur if pilot-induced oscillations become excessive. A power
pushover can occur on some gyroplanes that have the propeller thrust line above the center of gravity and do not have an
adequate horizontal stabilizer. In this case, when the rotor is unloaded, the propeller thrust magnifies the pitching moment
around the center of gravity. This nose pitching action could become self-sustaining and irreversible.
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The next time someone questions RAF stability maybe we should all just lead them to this FAA statement.
Maybe we should prompt the FAA to send an advisory alert to all current RAF owners and builders quoting the above.
How many deceased RAF pilots would still be alive if officially warned by the FAA about stability issues. Most I would think.
Arnie Madsen
Bell 47 G2