How can a small scrap of duct tape turn a Blackbird aircraft into a pile of burning wreckage? SR-71A 17953, a piece of which is shown above, first flew on June 4, 1965, from Air Force Plant 42 in Palmdale, California. She was a flight test aircraft based at Edwards Air Force Base, never flying operationally. During her testing, she performed the highest known (unofficial) flight of any SR-71 at 89,650 feet. Early tests performed by this aircraft gave information necessary for writing the flight manual for the whole fleet. Later in testing, 17953 became the first SR-71 fitted with a modified nose which housed an Optical Bar Camera (OBC) and an improved Electronic Countermeasures (ECM).

The first flight with this modified nose took place on December 18, 1969, piloted by Col. Joe Rogers with Maj. Gary Heidelbaugh as Reconnaissance Systems Officer (RSO). This mission was a functional check flight (FCF) of the ECM system. They lifted off from Edwards Air Force Base and rendezvoused with an F-104 chase plane piloted by Lt. Col. William Campbell. During this flight, Campbell noticed that the SR-71’s altitude was wandering. Campbell assumed that this variation was due to Rogers’s preoccupation with the the FCF. After in flight refueling, Rogers lit his afterburners to begin a climb and acceleration. At this time, Rogers and Heidelbaugh heard a loud bang and vibration from one of the engines. Rogers throttled back which stopped the vibration. A second attempt to reignite the afterburners led to more vibration. At this point, the aircraft stalled which caused the nose to rise dramatically. Rogers spoke two simple words to Heidelbaugh, “Let’s go”, and the crew ejected successfully. They fell from 65,000 feet, where the accident happened, landing safely. After the crew bailed out, the aircraft broke apart mid-air and fell north of Shoshone, California, severing power lines and causing an electrical blackout in the surrounding areas. Local firefighters responded to the scene and were soon replaced by the USAF who secured the crash site and the crew was picked up by the Inyo County Sheriff.

When an accident investigation board was assembled, they had a tough time finding a cause until they examined the newly modified nose section of the aircraft. During the modification process, a technician installed an improvised dust plug into a pitot-static line, forgetting to remove it before final assembly. 17953 flew with a rolled up piece of duct tape jammed inside the line that feeds airspeed and altitude information to the instruments in the cockpit. Rogers had a false reading, causing him to fly higher and slower than he thought he was. This created insufficient airflow to the compressors and ultimately stalled the aircraft. In the Blackbird’s case, a stall is unrecoverable.