Investigation into uncontained engine failure in Colorado – update

Citation

(2007), "Investigation into uncontained engine failure in Colorado – update", Aircraft Engineering and Aerospace Technology, Vol. 79 No. 4. https://doi.org/10.1108/aeat.2007.12779dab.015

Investigation into uncontained engine failure in Colorado – update

Investigation into uncontained engine failure in Colorado – update

On January 25, 2007, at approximately 4:50 MST, a US Airways Express Bombardier CL-600-2B19 (N17337), operated by Mesa Airlines as flight 2985 from Denver to Phoenix, sustained an uncontained failure and separation of components of the number 1 engine. The aeroplane was approximately 70miles west-southwest of Denver, climbing through 24,000ft when the event occurred. The aircraft returned uneventfully to Denver and none of the 55 persons aboard was injured.

The engine was a General Electric CF34-3B1. Preliminary examination of the number 1 engine revealed that the inlet, fan rotor assembly, fan containment case, and thrust reverser were missing. Examination of the aeroplane revealed impact damage to the fuselage, in-line with the plane of rotation of the engine fan rotor, as well as impact marks on the vertical and horizontal stabilizers.

Using a combination of information from the plane's flight data recorder, and radar data from the FAA and the military, NTSB investigators were able to determine when and where the event occurred. Vehicle performance engineers in the NTSB's laboratory in Washington, DC received the FDR and radar data on Monday, January 29. Within 24h, after identifying primary targets presumably from the aircraft, they were able to produce trajectory calculations and identify a 1mile² search area for the engine components.

With the co-operation of the Teller County Sheriff's Department and local residents, a search was conducted on Wednesday, January 31. In addition to five NTSB investigators, the team consisted of representatives from the FAA, General Electric Engines, an aircraft recovery company and officials from the county. The team searched the mountainous terrain all day in blowing snow and found about half of the fan disk, fan blades, parts of the engine cowling and thrust reverser, the engine spinner, and pieces of the fan containment case.

The wreckage arrived at the NTSB's materials laboratory on Friday, February 2 and was immediately examined by materials specialists. The point of origin of the fracture was identified. Investigators are currently examining the manufacturing and maintenance records of the engine to determine if existing fan disk inspections are appropriate and effective and whether further corrective action is warranted.