The SR-71's
Lockheed manufactured the ejection seats used in the two NASA SR-71 aircraft flown at Dryden. The system is a modified version of the Lockheed C-2 ejection seat used in F-104's called the Lockheed ADP F-1.
The parachute used on the SR-71 seat is a back style chute. The sequence of events when the ejection process is initiated is similar to the ACES II and the Martin-Baker systems. The aircraft, which can cruise at altitudes up to 90,000 ft at speeds of more than 2000 mph, has a crew of two. Each person wears a full pressure suit and helmet, much like a space suit. The pressure suits and helmets are required to provide the SR-71 flightcrew protection from the possible loss of cockpit pressure. The cockpit is normally pressurized to a cabin (cockpit) altitude of 35,000 ft. Should this pressure be lost the suit will protect the crewmember from the loss of pressure.
When an ejection from an SR-71 takes place, regardless of altitude, a drogue parachute is instantly deployed to stabilize the fall of the crewmember and seat. The main parachute is timed for release at 15,000 ft, the same altitude at which the seat is automatically separated from the crewmember. In ejections above 15,000 ft, crewmembers remain strapped to the seats until a moment before the main parachute is released.
The completely equipped SR-71 ejection seat system weighs about 400 lb.