Boeing 767-332 N136DL

Summary

On 20 June 1996 at about 05:22 local time, a Boeing 767-332 registered N136DL, operated by Delta Air Lines, was involved in an incident near Salt Lake City, Utah, United States. 186 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

20 June 1996 at 05:22

Classification

Incident

Location

Salt Lake City, Utah, United States

Nearest airport

Salt Lake City Intl (SLC)

Coordinates

40.8098, -111.9397

Aircraft

Boeing 767-332

Registration

N136DL

Category

Airplane

Engines

2

Operator

Delta Air Lines

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Portland

Aircraft damage

Minor

Weather

VMC

Light

Night/Dark

NTSB number

SEA96IA131

Nobody was injured.

failure of maintenance personnel to properly disconnect (disengage) the right integrated drive generator (IDG) in compliance with the MEL dispatch procedure, which allowed the right IDG to overheat. Factors relating to the incident were: low oil pressure in the right IDG, and insufficiently defined company developed dispatch procedure.

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

Read the full NTSB narrative

During taxi for departure a 'R GEN OFF' and 'R GEN DRIVE' EICAS message illuminated indicating a malfunction of the right integrated drive generator (IDG), and the crew returned the Boeing 767 to the gate. Maintenance was notified, and a mechanic was dispatched to the aircraft. The mechanic reported that he 'assumed (the) crew had disconnected (the) IDG.' The captain reported that he was advised by the mechanic that 'the IDG is disconnected.' The aircraft was prepared and released according to its MEL for the flight using the left IDG and APU generator. During climbout a 'R STARTER CUTOUT' EICAS message illuminated followed by a fire warning on the right engine. Both fire bottles were exhausted, the fire warning extinguished, and the aircraft was returned to Salt Lake City, for emergency landing on runway 16L. Postincident examination of the engine revealed the fire-damaged remains of the right IDG and its magnesium housing. A download of digital data from the aircraft revealed that the original EICAS and IDG annunciations were related to low oil pressure within the IDG. An FAA inspector, who examined the aircraft immediately following the event, found the right IDG disconnect switch still safety wired (the IDG cannot be disconnected without breaking the wire and depressing the switch). The MEL dispatch procedure developed by the carrier did not address the need to run the associated engine at or above idle in order to successfully disconnect the IDG.

Quoted verbatim from the NTSB record.