The G1000 Turn rate indicator shows a lower value than it should.
Here you can see the plane in a 24° bank at 163 knots true. The turn indicator shows a turn rate of 2.74°/s or around 2.19min/360°.
However if you time the turn, or put the data into a calculator, you will see the turn rate is correct. 3°/s or 2min/360°.
The Turn rate indicator uses the “DELTA HEADING RATE” Avar, which matches the Y body turn rate. These Avars show the yaw rate of the aircraft. This would work fine if the plane wasnt in a bank however trigonometry comes into play.
The plane is banking at 24°. The Cosine of 24° is 0.913.
3*0.913 = 2.74, which matches the displayed turn rate.
The turn rate indicator should be tied to the heading of the aircraft and not the yaw rate. For aircraft with old mechanical turn rate idicators this is fine as the error is cancelled out for the normal speeds, but for aircraft with EFIS, this is wrong.
BR
-Tommy