FAA Flight Instructor Airplane (FIA)Aerodynamics and Principles of FlightHard
On a V-g diagram, the point where the positive limit load factor line intersects the stall speed line is called corner velocity, shown at 130 KIAS and +4.4G. If a pilot flies at 150 KIAS (above corner velocity) and applies an abrupt full aft control input, what is the most likely consequence?
- AThe wing will always stall before the load factor reaches the airplane's limit load, fully protecting the structure
- BThe load factor is automatically capped at +4.4G at any airspeed above corner velocity
- CCorner velocity represents the minimum safe airspeed for all maneuvering flight, including slow flight
- DThe airplane could exceed its limit load factor before the wing stalls, risking structural damage
Show answer & explanationAnswer & explanation
Correct answer: D. The airplane could exceed its limit load factor before the wing stalls, risking structural damage
Corner velocity is the speed at which the wing stalls exactly at the limit load factor. Above this speed, the wing can generate the limit load factor without stalling, so an abrupt control input can overstress the airframe before the wing stalls, unlike below corner velocity where the stall protects the structure.
Why the other options are wrong
- A. Wrong — this protection only applies at or below corner velocity/Va, not above it
- B. Wrong — load factor is not capped; it can exceed +4.4G with sufficiently abrupt input above corner velocity
- C. Wrong — corner velocity relates to load factor protection, not a general minimum safe airspeed
V-g Diagram / Corner Velocity
A graph relating airspeed to load factor, showing structural and aerodynamic limits; corner velocity is where the stall speed line meets the positive limit load factor line.
- Below corner velocity, a stall occurs before exceeding limit load factor
- Above corner velocity, structural limits can be exceeded before stalling
- Corner velocity corresponds closely to maneuvering speed (Va)
Memory trick: Corner velocity is the fork in the road: below it the wing quits first, above it the airframe might