61-7965 (SR-71A) This aircraft was lost on 25 October 1967 after an Inertial Navigation System (INS) platform failed, leading to erroneous attitude information being displayed in the cockpit. During a night flight, the INS gyro had tumbled. There were no warning lights to alert pilot Captain Roy L. StMartin and RSO Captain John F. Carnochan. In total darkness, in a steep dive and no external visual references available, the crew had little alternative. They both ejected safely. The incident occurred near Lovelock, Nevada.
The crash site was discovered on January 9, 1999, by Peter Merlin and Tony Moore. Here is the official report of the accident, courtesy of Peter Merlin:
SR-71 serial number 61-7965, call sign "ASPEN 28", departed Beale AFB at 0058Z on 25 October 1967 for a three hour night training flight. Papa Route consisted of a high-altitude, supersonic leg to BUSY PALACE air refueling area near Albuquerque followed by a second climbing acceleration east of Denver and return to Beale on a westbound leg north of Salt Lake City. The flight progressed normally through the air refueling and second acceleration to supersonic cruise. Descent and deceleration from cruise was initiated in the vicinity of Elko, Nevada, approximately two hours and fifteen minutes after takeoff. After completion of checklist item "Throttles - retard and set 6300 to 6100 RPM" in the Mach 2.0 checklist, the pilot observed a warning flag on the bank steering bar of the attitude director indicator (ADI). At this time the pilot also observed that the autopilot had become disconnected.
The ADI showed wings level flight and the horizontal situation indicator (HSI) showed straight, non-turning flight. Because of the warning flag on the ADI steering bar, the pilot switched the attitude reference source to the Flight Reference System (FRS). The ADI showed an immediate unusual attitude of undetermined magnitude, and both the warning flag on the steering bar and the OFF flag on the ADI appeared simultaneously. The pilot advised the RSO that he had attitude indicator malfunctions and the RSO confirmed that his astro inertial/navigation system (ANS) had stopped functioning as a valid reference source. The RSO, on FRS, observed his attitude indicator reflecting a large left wing low, diving turn. Due to the radical attitude displayed in FRS, he stated to the pilot that the FRS was inoperative. However, there were no OFF flags on the RSO's attitude indicator. The RSO switched to ANS and it showed wings level, constant heading. The crew was not aware that the aircraft was making a 180-degree turn towards the east as observed by Oakland Center. The speed had increased to 480 KEAS where the pilot felt that he had stopped the trend of increasing airspeed. The pilot had no outside reference to assist him in the recovery from the unusual attitude because of the darkness. Recovery could not be effected using the standby attitude indicator. The pilot directed the RSO to bailout, passing an estimated 30,000 feet. The pilot remained with the aircraft for an unknown duration, continuing his efforts to recover, but was unsuccessful. He ejected from the aircraft at an unknown altitude (10,000 feet) and speed (Mach 1.4). Both crew members had successful ejections.
The aircraft struck the ground in a near vertical dive and was totally destroyed upon impact. The crash occurred at 0320Z in an isolated area with no witnesses at or near the scene of the accident. Total flight time was approximately two hours and twenty minutes.
"Today, the crater is gone. Only scattered debris remains to mark the site." - Peter Merlin
Following the accident board investigation instrument locations were changed on the entire fleet of Blackbirds and the amended night flight rules required pilots to have at least 50 hours daytime flight in the SR-71's prior to flying night sorties.