Certified Flight Instructor (CFI) Practice Exam

What does the term Vef refer to in aviation?

1. Design flap speed

2. Speed at which the critical engine is assumed to fail during takeoff

3. Maximum speed in level flight with maximum continuous power

4. Never exceed speed

The correct answer is: Speed at which the critical engine is assumed to fail during takeoff

The term "Vef" stands for the speed at which the critical engine is assumed to fail during takeoff. This is a crucial factor in multi-engine aircraft performance calculations, as it directly impacts how the aircraft will behave if an engine failure occurs shortly after takeoff. Knowing Vef provides pilots with essential information for maintaining control of the aircraft during critical phases of flight, particularly takeoff, where load factors and engine thrust are at their limits. It informs decisions regarding takeoff performance, such as the required runway length and climb capability post-engine failure. In this context, understanding the implications of Vef helps pilots execute a safe and effective takeoff, ensuring that they are prepared to react appropriately in the event of an engine failure. This focus on Vef contributes to a more comprehensive understanding of aircraft performance and safety procedures in multi-engine operations.