Ultimate load factor is defined as what?

• A. The load that causes physical breakdown in a strength test
• B. The maximum takeoff weight
• C. The load used for interior design
• D. The load corresponding to stall speed

Answer: (A)

The ultimate load factor is the load factor at which the aircraft structure reaches its ultimate strength and would fail in a structural test. In flight, loads are described as multiples of weight (L/W), with the limit load representing the maximum load expected during normal operation. The ultimate load factor is higher and defines the point of structural failure in testing, providing a margin above the limit load for safety. That’s why the statement describing the load that causes physical breakdown in a strength test best fits. The other options don’t describe structural failure: maximum takeoff weight is a weight limit, interior design loads pertain to cabin furnishings, and stall speed is a performance parameter not tied to structural failure.