McDonnell Douglas MD-88 N927DA

Summary

On 6 July 1996 at about 19:24 local time, a McDonnell Douglas MD-88 registered N927DA was involved in an accident near Pensacola, Florida, United States. 144 people were on board and 2 died, 2 were seriously injured, 3 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 July 1996 at 19:24

Classification

Accident

Location

Pensacola, Florida, United States

Nearest airport

Pensacola Regional (PNS)

Coordinates

30.4705, -87.1905

Aircraft

McDonnell Douglas MD-88

Registration

N927DA

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Atlanta

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DCA96MA068

2 people died.

the fracture of the left engine's front compressor fan hub, which resulted from the failure of Delta Air Lines' fluorescent penetrant inspection process to detect a detectable fatigue crack initiating from an area of altered microstructure that was created during the drilling process by Volvo for Pratt & Whitney and that went undetected at the time of manufacture. Contributing to the accident was the lack of sufficient redundancy in the in-service inspection program. (NTSB Report AAR-98/01)

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

During the initial part of its takeoff roll, the airplane experienced an engine failure. Uncontained engine debris from the front compressor front hub (fan hub) of the #1 (left) engine penetrated the left aft fuselage. Two passengers were killed and two others were seriously injured. The takeoff was rejected, and the airplane was stopped on the runway. The fan hub had fractured through a tierod hole and blade slot. Some form of drill breakage or drill breakdown, combined with localized loss of coolant and chip packing, had occurred during the drilling process, creating an altered microstructure and ladder cracking in the fan hub. Drilling damage extended much deeper into hole sidewall material than previously anticipated by P & W. Fatigue cracks initiated from the ladder cracking in the tierod hole and began propagating almost immediately after the hub was put into service in 1990. The crack was large enough to have been detectable during the last fluorescent penetrant inspection at Delta. Delta's nondetection of the crack was caused either by a failure of the cleaning and fluorescent penetrant inspection processing, a failure of the inspector to detect the crack, or some combination of these factors.

Quoted verbatim from the NTSB record.