Lockheed L-1011-385-1 N735D

Summary

On 30 December 2000 at about 07:15 local time, a Lockheed L-1011-385-1 registered N735D was involved in an incident near Honolulu, Hawaii, United States. 300 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

30 December 2000 at 07:15

Classification

Incident

Location

Honolulu, Hawaii, United States

Coordinates

21.3507, -157.8806

Aircraft

Lockheed L-1011-385-1

Registration

N735D

Category

Airplane

Engines

3

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

San Fransisco → Honolulu

Aircraft damage

Minor

Weather

IMC

Light

Night/Dark

NTSB number

LAX01IA066

Nobody was injured.

the electrical wire arcing and burning as result of insulation degradation, which more than likely resulted from improper clamping.

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

Read the full NTSB narrative

The air transport aircraft was cruising 2 hours after departure at 32,000 feet in clouds when it experienced an electrical discharge near the co-pilot's over window panel. Just prior to the discharge event, the flight crew observed a phenomenon known as St. Elmo's Fire, during which time loud popping noises were heard in the radios. After the discharge, sparks, smoke, and a strong acrid smell of electrical burning were noted from near the co-pilot's over window panel. The smoke and fume checklist was performed, halon was applied on two separate occasions, and the relative circuit breakers and electrical switches were opened. The flight landed uneventfully 45 minutes later. Post incident examination of the affected wires revealed that electrical arcing and shorting had occurred between the airplane structure, a clamp, and a 30-wire bundle. The affected wire bundle passed behind the flight engineer's station and overhead to the heated windshields. The wire bundle and its clamps were examined and it was noted that the wires were insulated with aromatic polyimide, which is susceptible to arc tracking and insulation flashover. Though the insulation did not display complete insulation breaches, it was noted that the arcing event initiated near a clamp, which was destroyed by the event. The clamp aft of the burned area was of normal size, while the clamp forward of the destroyed one was too small. It is plausible the insulation was either chafed or crimped by the damaged clamp, allowing the arcing event to take place. In turn, the arc tracking and insulation flashover then consumed the surrounding wires.

Quoted verbatim from the NTSB record.