On Wednesday, 22 April 2015 14:58:44 UTC+3, Martin Gregorie wrote:
One question: I haven't tried this, but my guess is that a mechanical T&B
will come up showing the correct reading if it is switched on while
turning. It will do this because what it shows is the amount a spring is
deflected by the precession force a gyro applies to it when the aircraft
yaws. Am I right in thinking this?


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martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Yes it will indicate rate of turn even if switched on during thermalling. There is always horizontal acceleration during turning, and gyro indicates only this as rate of turn. However being used to temperamental 50-something years old T&B's I might wan't to check gyro action well before entering cu-nim (got to admit that I've flown into smaller clouds switching gyro on "on the fly" just before entering cloud). I think it takes 15-30 secs to achieve stable gyro rotation, or little bit less with LiFePo4 battery as these old things seems to like little extra voltage compared to lead acid batteries.