What bank angle corresponds to a standard rate turn at 120 knots, using the rule of thumb?

• A. 18 degrees
• B. 15 degrees
• C. 12 degrees
• D. 20 degrees

Answer: (A)

A standard rate turn is a turn at 3 degrees per second, so the bank angle you use must increase with airspeed to keep that same rate. A handy rule of thumb is to take the airspeed in knots, divide by 10, and add about 5 degrees. At 120 knots that’s 12 + 5 = 17 degrees, which pilots typically round to about 18 degrees. This bank angle balances lift and centripetal force to produce the standard rate turn at that speed. If you used a significantly smaller bank, the turn rate would be slower; if you used a larger bank, the turn rate would be faster than standard. Therefore, 18 degrees best matches a standard rate turn at 120 knots.