Turn rate

Turn rate is how fast a level turn sweeps heading, in degrees per second. Like radius it depends only on bank angle and speed (V in knots).

ω = 1091 · tan φ / V (ω in °/s, φ is the bank angle, V in knots)

• The constant 1091 folds in gravity and the knot→ft/s conversion, so V is in knots and ω in °/s (derived standard turn geometry, not a value printed in the CARs/TC AIM/TP 1102). If a speed is given in mph, convert first (1 kt ≈ 1.15 mph).
• Rate falls as speed rises: for the same bank a faster aircraft sweeps fewer degrees per second, because the turn is spread over a longer arc. Steepening the bank (more tan φ) quickens it.
• A rate-one (standard-rate) turn is 3 °/s, a full 360° in two minutes. Instrument turns use the bank that gives this rate, normally not more than 30° (TP 1102). At light-trainer speeds that bank is modest, and it must be increased as speed rises.

Trap: swapping rate with radius. As speed falls it is the rate that increases (the radius shrinks); and rate divides by V, it does not use V².

Practice