Gimbals angle – turn coordinator

[Poopsmith]

Got a question I am having trouble finding an answer to.

Can anyone tell my why the gyro gimbals on a turn coordinator are situated 30-35 deg from the longitudinal axis? I understand that putting the gyro at an angle allows the instrument to display roll and yaw but why 30-35 deg? Why not 45 deg?


thank you for any input.

[tgrayson]

Originally Posted by Poopsmith

why 30-35 deg? Why not 45 deg?

No authoritative info on this, but I suspect the intent is to make the device more sensitive to yaw than roll. The turn-and-bank indicator only detects yaw, of course, but the idea of the improvement of the turn coordinator is that it would help a pilot maintain wings level in IMC upon the loss of the attitude indicator.

The more roll it detects, the less yaw it registers, so I'm guessing everyone accepted the device should remain mostly a yaw detector.

Some people feel that the turn coordinator isn't actually an improvement over the turn-and-bank, because it's more jiggly in turbulence.

[Poopsmith]

thank you for the input. That was kind of what I was thinking of but was not sure.

I think the additonal benifits of the turn coordinator out weigh the instruments jiggliness, especialy in partial panel.

[meritflyer]

The turn coordinator differs from the older turn and bank indicator in that the turn coordinator has the gyro canted at a 30 degree angle. This allows the turn coordinator to respond to roll as well as turn. When the aircraft is rolling, the turn coordinator deflection is proportional to the rate of roll and not the rate of turn. Once the roll has stopped, the turn coordinator deflection will settle back to an amount which indicates the rate of turn.