Certified Flight Instructor (CFI) Practice Exam

What speed must be known to ensure successful takeoff under all engine conditions?

1. Design flap speed

2. Minimum control speed with critical engine inoperative

3. Maximum speed in level flight

4. Lift off speed

The correct answer is: Lift off speed

Lift-off speed is crucial for ensuring a successful takeoff under all engine conditions. This speed is the minimum required to achieve sufficient lift to allow the aircraft to leave the ground safely. It involves a combination of factors, including aircraft weight, center of gravity, and atmospheric conditions. Knowing the lift-off speed ensures that the pilot can maintain control of the aircraft during the initial phase of takeoff when the aircraft is still on the ground and transitioning to an airborne state. It is a critical parameter that helps in managing the aircraft's performance and ensuring that approval for takeoff is only given when conditions allow for safe liftoff. In contrast, design flap speed relates to configurations used during takeoff but does not directly ensure that the aircraft will achieve a successful takeoff. Minimum control speed with a critical engine inoperative is important for managing performance in multi-engine aircraft scenarios but is specific to critical engine failure situations rather than general takeoff. Maximum speed in level flight is not relevant to the takeoff phase, which focuses on lift rather than sustained level flight performance.