Spins... tumble or no tumble?

[BYUFlyr]

Looking for some clarification on the tumbling gyro issue.... I've heard from other instructors that spinning an airplane is bad on the gyros (it causes them to tumble). Some schools prohibit spinning on their airplanes because thay want to preserve their gyros. However, while reviewing the FAA's Instrument Flying Handbook I noticed that "older artificial gyros were limited in the amount of pitch or roll they could tolerate.... Because of this limitation, these instruments had a caging mechanism that locked the gyro.... Newer imstruments do not have these restrictive tumble limits; therefore they do not have a caging mechanism."

So does this mean that newer AI's without a caging knob do not tumble; therefore spinning is ok?

 

[VNugget]

I don't know much about the finer workings of instruments, but just a data ponit... a few times I rocked and rolled in a 70s 150 aerobat with a standard 6-pack, and the gyros tumbled.

Hell, in a 182 I flew the DG tumbled from a normal steep turn.

 

[DrewBlows]

I've seen modern gyros tumble doing spins and unusual attitude recovery (occasionally while doing steep turns), so I would say that the newer gyros are resistant to tumbling, but not immune.

So, is tumbling a gyro bad for it? I don't know, it sure doesn't look like it would be good for it. I suppose that the bushings would be more susceptible to wear, but then I've never actually seen the inside of a gyro.

 

[Vector4fun]

A few spins likely won't ruin the gyros, but over time causes them to wear faster. The flight schools I worked at years ago always had a "spin airplane" with lousy gyros. We weren't allowed to spin any of the others. I dunno, maybe the newest (last 5-10 years) aircraft have better, but I won't be tumbling any of my 30 yr old gyros if I can help it. I don't have any extra $500 bills laying around.