dead man’s curve
n.— «Failure of the clutch cable in the final moments of a flight, when the pilot hovers at low altitude before landing, wouldn’t have left Nagle enough time or airspeed momentum to recover—a vulnerable zone helicopter pilots call the dead man’s curve, slang for the height-velocity curve.» —“Lucky to be alive” by Patrick Springer The Forum (Fargo, N.D.) Apr. 25, 2005. (source: Double-Tongued Dictionary)