FAA Sport Pilot Airplane (SPA)Aircraft Performance and SystemsEasy
A pilot must clear a 50-foot obstacle shortly after takeoff on a short runway. Which airspeed should be used to maximize climb performance over the obstacle?
- AVY, best rate of climb speed
- BVFE, maximum flap extended speed
- CVX, best angle of climb speed
- DVA, maneuvering speed
Show answer & explanationAnswer & explanation
Correct answer: C. VX, best angle of climb speed
VX (best angle of climb speed) gains the most altitude for a given horizontal distance traveled, making it ideal for clearing obstacles close to the runway. VY gains altitude fastest per unit time but covers more ground distance.
Why the other options are wrong
- A. VY maximizes altitude per minute, not per horizontal distance covered.
- B. VFE is a flap operating limit, not a climb speed.
- D. VA is a structural limit speed for turbulence, unrelated to climb performance.
Best Angle of Climb Speed (VX)
The airspeed that produces the greatest gain in altitude over the shortest horizontal ground distance, used for obstacle clearance.
- Slower than VY
- Used for short-field/obstacle takeoffs
- VY is used for maximum altitude gain per unit time
Memory trick: VX crosses obstacles, VY climbs fast over time.