ASN Wikibase Occurrence # 277572
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information
Narrative:The USAF Rockwell B-1B, 85-0089, assigned to Dyess Air Force Base, 7th Bomb Wing, 7th Maintenance Group 7th Aircraft Maintenance Squadron, experienced a catastrophic engine failure and fire on the no.1 engine while undergoing maintenance on the main ramp at Dyess AFB, Texas. The aircraft suffered catastrophic damage to the no.1 engine, as well as extensive fire damage to the left nacelle and wing. Debris from the explosion struck one airman who suffered minor injuries. The estimated cost of damage sustained by the aircraft was $14,943,680.00.
|Date:||Wednesday 20 April 2022|
Rockwell B-1B Lancer
|Owner/operator:||US Air Force (USAF) |
|Fatalities:||Fatalities: 0 / Occupants: |
|Aircraft damage:|| Substantial|
|Location:||Abilene-Dyess AFB, TX -
United States of America
|Investigating agency: ||USAF AIB|
|Confidence Rating:|| Accident investigation report completed and information captured|
Shortly before the accident, the Maintenance Crew performed routine corrective maintenance, in accordance with technical orders, in response to the aircraft's malfunctioning no.1 engine variable area exhaust nozzle. During run-up to maximum augmenter to verify correct performance of the no.1 engine variable area exhaust nozzle, the no.1 engine catastrophically failed, ejecting its 2nd Stage Fan Disk from the intake section and severing fuel lines, which caused a fire to erupt in the engine. The 2nd Stage Fan Disk continued to flyaway from the aircraft and landed over five hundred feet from the aircraft. The maintenance crew executed emergency engine shutdown procedures and egressed away from the aircraft. Emergency crews quickly responded and extinguished the fire within ten minutes.
The Accident Investigation Board President found by a preponderance of the evidence that high cycle fatigue on the no.1 engine's 2nd Stage Fan Disk was the cause of the accident. Laboratory testing demonstrated that high cycle fatigue initiated a crack on the surface of the 2nd Stage Fan Disk at the corner of a blade slot and the forward face of the disk. The crack, once initiated by the stress induced from repeated acceleration and deceleration of the engine, was propagated by a mix of high cycle and low cycle fatigue. The crack and its initial growth increased the stress beyond the 2nd Stage Fan Disk's yield strength, leaving it susceptible to low cycle fatigue. The surface crack grew to a depth of approximately 0.7 inches before the 2nd Stage Fan Disk broke apalt causing the #1 engine to fail catastrophically. The root cause of the high cycle fatigue that caused the initial crack in the 2nd Stage Fan Disk could not be determined.
| || |
|Investigating agency: ||USAF AIB |
|Report number: || |
|Status: ||Investigation completed|
|Duration: ||8 months|
|Download report: || Final report|
||Updated [Time, Registration, Cn, Total occupants, Departure airport, Destination airport, Source, Embed code, Damage, Narrative, Accident report]|
The Aviation Safety Network is an exclusive service provided by:
CONNECT WITH US:
©2023 Flight Safety Foundation