Minimum Drag Trim Technique
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Location: Sale, Australia
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Precession only occurs the direction of a gyro's axis is being changed. The discussion is about trimming in straight & level flight: no yaw, no pitch rate, therefore no precession, therefore no right (or left) wing rise
BA
Yes, you are right, there is a pitch rate as you describe. Without going into the maths, I think the effect is probably negligible.
Many moons ago, in my experience of aerobatics and other vigorous manouevres in jet fighters and trainers, we could get pitch rates of, I guess, well over 10 degrees per second, and I was never aware of any gyroscopic effects in such flying. That's why I have the gut feel that a few degrees an hour is not significant.
Yes, you are right, there is a pitch rate as you describe. Without going into the maths, I think the effect is probably negligible.
Many moons ago, in my experience of aerobatics and other vigorous manouevres in jet fighters and trainers, we could get pitch rates of, I guess, well over 10 degrees per second, and I was never aware of any gyroscopic effects in such flying. That's why I have the gut feel that a few degrees an hour is not significant.
Last edited by kenparry; 19th Feb 2010 at 09:52. Reason: added second paragraph
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ken, you are quite right, when you do the maths they are negligible. The FARs do address gyroscopic loads, and when you read the referenced sections they apply to maneuvers about the three axis.
§ 25.371 Gyroscopic loads.
The structure supporting any engine or auxiliary power unit must be designed for the loads including the gyroscopic loads arising from the conditions specified in §§25.331, 25.341(a), 25.349, 25.351, 25.473, 25.479, and 25.481, with the engine or auxiliary power unit at the maximum rpm appropriate to the condition. For the purposes of compliance with this section, the pitch maneuver in §25.331(c)(1) must be carried out until the positive limit maneuvering load factor (point A2in §25.333(b)) is reached.
§ 25.371 Gyroscopic loads.
The structure supporting any engine or auxiliary power unit must be designed for the loads including the gyroscopic loads arising from the conditions specified in §§25.331, 25.341(a), 25.349, 25.351, 25.473, 25.479, and 25.481, with the engine or auxiliary power unit at the maximum rpm appropriate to the condition. For the purposes of compliance with this section, the pitch maneuver in §25.331(c)(1) must be carried out until the positive limit maneuvering load factor (point A2in §25.333(b)) is reached.
