Accident Overview
On the evening of 29 October 2019, a flight of three F-16 aircraft departed Holloman Air Force Base (AFB), New Mexico, at 1826 hours local for a routine night training mission. The mishap aircraft (MA), an F-16C Block 42 with tail number 90-0755 assigned to the 314th Fighter Squadron, crashed on privately-owned land approximately 95 miles southeast of Holloman AFB at about 1906 hours. The aircraft, valued at $24,229,944, was completely destroyed upon impact. The mishap pilot (MP) ejected safely and was recovered by a United States Army helicopter from Fort Bliss, Texas. Holloman AFB personnel conducted environmental remediation of the crash site.
Mission and Sequence
The mission was scheduled as an instructor continuation training sortie to maintain night vision goggle low-altitude navigation currency. The mishap flight (MF) consisted of three instructor pilots, all current and qualified. Approximately 40 minutes after takeoff, while flying number three position in trail formation, the MA experienced catastrophic engine failure resulting in an uncontrollable engine fire at low altitude, leading the MP to eject.
Findings and Cause
The Board President determined, by a preponderance of the evidence, that the mishap was caused by catastrophic failure of the engine due to the failure to install the 1st Stage Rear Air Seal during overhaul of the engine's Inlet Fan Module by depot-level maintenance personnel at Tinker Air Force Base, Oklahoma, in September 2016. Without the seal, the 2nd Stage Fan Blades migrated forward until excessive strain caused liberation of the blades, leading to loss of thrust and an uncontained engine fire fueled by a perforated A-1 fuel tank.
Additionally, the Board President found that unqualified and untrained maintenance personnel, lack of supervision, and negligent procedural practices at the depot substantially contributed to the mishap. Specifically, an unqualified and untrained mechanic, not under immediate supervision of a trainer, failed to follow checklist procedures. The error was compounded when the mechanic trainee continued assembly beyond the point where proper installation could be verified, yet both the Depot Maintenance Trainer (DMTr) and Depot Maintenance Employee (DME) stamped completion regardless. The Board President found the DMTr, DME, and Depot Maintenance Trainee all causal to the mishap.