At what bank angle is the load factor doubled?

The correct answer is 60 degrees because the load factor in an aircraft increases with the angle of bank. When an aircraft banks, the vertical component of lift increases the effective weight the aircraft must support, which results in an increased load factor.

At a bank angle of 60 degrees, the cosine of the angle is 0.5 (cosine of 60 degrees). This means the vertical lift component is half of the total lift needed to maintain level flight, effectively doubling the load factor compared to straight and level flight.

In contrast, at a 45-degree bank angle, the load factor increases to 1.41 (a factor of approximately 1.4), corresponding to the square root of 2, which does not double the load factor but rather increases it by about 41%. A bank angle of 30 degrees results in a load factor of about 1.15, while at 90 degrees (which is vertical flight), the load factor would theoretically be extremely high, but still does not relate to the doubled condition in this specific context. Hence, 60 degrees is the point at which the load factor is explicitly doubled.