FAA Private Pilot Airplane (PAR)Aerodynamics and Aircraft SystemsMedium
An airplane is established in a coordinated, level turn at a 45-degree bank angle. What approximate load factor is being imposed on the airplane?
- A2.0 G
- B1.4 G
- C3.0 G
- D1.0 G
Show answer & explanationAnswer & explanation
Correct answer: B. 1.4 G
Load factor in a level turn equals 1 divided by the cosine of the bank angle. For 45 degrees, cos(45°) ≈ 0.707, so load factor = 1 / 0.707 ≈ 1.41 G, which rounds to approximately 1.4 G.
Why the other options are wrong
- A. 2.0 G corresponds to a 60-degree bank, not 45 degrees.
- C. 3.0 G corresponds to roughly a 70.5-degree bank, much steeper than 45 degrees.
- D. 1.0 G only applies to unaccelerated, wings-level flight, not a banked turn.
Load Factor in a Turn
Load factor = 1 / cos(bank angle) for a level, coordinated turn.
- 30° bank ≈ 1.15 G
- 45° bank ≈ 1.41 G
- 60° bank = 2.0 G
- Load factor increases stall speed proportionally to its square root
Memory trick: Steeper bank, steeper climb in G's: 1/cos does the trick.