Aerodynamic Phenomenon: A Detailed Look At the Coffin Corner

Simple Flying

Explanations about the coffin corner are sometimes vague or lack in detail.

Photo: Dassault

Coffin Corner refers to the flight region where stall speed is close to the aircraft's critical Mach number, leading to loss of lift and potential catastrophe.
High-speed stalls are caused by shockwave formation, while low-speed stalls increase with altitude due to compressibility.
Airliners must have enough margin for maneuvering at high ceilings to avoid high-speed and low-speed buffets. U2 Dragonfly flies close to its coffin corner.