Three of the four B-1A prototypes featured a single crew escape capsule for the crew members. For the fourth prototype and for the B-1B, this was changed to use conventional ejection seats. One source gives the reason "due to concerns about servicing the pyrotechnical components of the system," while another says this was done "to save cost and weight." On August 29 1984, B-1A prototype #2 crashed and the capsule was ejected at low altitude. The parachute deployed improperly and one of the three crewmembers aboard died.