[outworlder]

This is called the "coffin corner". It varies for different aircrafts, but they all have it, including commercial liners.

[WalterBright]

The P-51 had an interesting problem shared with other high torque single engine fighters of its day. If you're coming in for a landing, with the engine idling, decided to abort and firewalled the throttle, the airplane would rotate about the crankshaft.

This killed a lot of pilots.

[arethuza]

"The aircraft's stall speed at that altitude is only 10 knots (12 mph; 19 km/h) below its maximum speed"

http://en.wikipedia.org/wiki/Lockheed_U-2