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Ben Chiu Certificates/Ratings/Crew Stations: 9. "RE: CG manipulation" 05-27-02, 08:21z  Greetings avbug: First off, thanks so much for the very detailed insights about carb ice and CG manipulation. I'm sure the others feel the same as I do--well done! > Weight shift for trim and control is one of the most origional and > basic forms of aircraft control. In a hang glider, for example, body > english-weight shift is everything. That's right. Thanks for the reminder. I tend to use body english when I sit in the back seat of an airplane watching another pilot making a landing. I doubt my weight shifting/body english actually does anything, but that doesn't stop me from subconsciously doing the same when I go bowling either! > During flight test operations to explore the CG envelope and attendant > aircraft performance, very often a sliding weight is used to vary the > CG. This weight is usually run on a cable and rod arrangement or with a > chain and sprocket, in order to explore a variety of CG applications > during one flight. The CG is precalculated, and can be set as required > at intervals to conduct the test. This is the kind of mechanism I was thinking of at first, but it may be too elaborate (complexity and weight-wise) for aerobatic application we envision. > Some aircraft trim systems have used weight shift arrangements using a > weight in the floor or in a track somewhere in the aircraft. I never knew that. Can you give us an example of an aircraft that does/did use this? > Remember that when having a discussion of spins, the aft CG isn't what > causes a spin. A spin results following a stall; the aircraft must be > stalled first. Many other factors are involved in spin recovery, > including aircraft design, power application, control input, etc. Rgr. I should have explained that my example of a flat spin and rearward CG worst case scenario was to emphasize that in that situation a rearward CG would reduce elevator effectiveness (due to the shorter arm between the CG and elevator) and may make recovery from that maneuver impossible--hense requiring a foolproof weight ejection system in that situation. Thanks again! Ben -= VPC OffLine Reader Version 1.1.0.0 =- Registered to: Ben Chiu -OLR.PL v1.76- Remove | Alert Edit | Reply | Reply With Quote | Top

Table of Contents

Subject      Author      Message Date     ID      CG manipulation    Ben Chiu       05-20-02              RE: CG manipulation    DHamblin       05-20-02       1            RE: CG manipulation    Ben Chiu       05-20-02       2                 RE: CG manipulation    vgbaron       05-20-02       3                      RE: CG manipulation    Mike_Greenwood       05-21-02       4                      RE: CG manipulation    Ben Chiu       05-21-02       5                           RE: CG manipulation    vgbaron       05-21-02       6                                RE: CG manipulation    ChipB727       05-21-02       7         RE: CG manipulation    avbug       05-26-02       8            RE: CG manipulation    Ben Chiu       05-27-02       9

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