The dodo bird effect, or welcome to "coffin corner"

Well, like a dodo bird falling off a cliff,  it looks so far like Air France flight 447 went belly down, as in a vertical shaft. For those abaord it must’ve been beyond words–only screams. Here’s a take on the physics of  it, known as the coffin corner: “The coffin corner or Q-Corner is the altitude at or near which an aircraft’s stall speed is equal to the critical Mach number, at a given gross weight and G loading. At this altitude the aircraft becomes nearly impossible to keep in stable flight. Since the stall speed is the minimum speed required to maintain level flight, any reduction in speed will cause the airplane to stall and lose altitude. Since the critical Mach number is maximum speed at which air can travel over the wings without losing lift due to flow separation and shock waves, any increase in speed will cause the airplane to lose lift, or to pitch heavily nose-down, and lose altitude. The “corner” refers to the triangular shape at the top of a flight envelope chart where the stall speed and critical Mach number lines come together…” From Wikipedia article.

About these ads