Aircraft Accident/Incident Report

Honolulu, Hawaii 96819
Friday, December 29, 2000 21:15 HST

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

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

Event Information

Type of Event Incident
Event Date 12/29/2000
Event Day of the Week Friday
Time of Event 2115
Event Time Zone Hawaii Standard Time
Event City Honolulu
Event State HAWAII
Event Country --
Zipcode of the event site 96819
Event Date Year 2000
Event Date Month 12
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude --
Event Location Longitude --
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Night/Dark
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Unknown
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 0
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 0
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 300
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 14302
NTSB Notification Source FAA
NTSB Notification Date Dec 30 2000 12:00AM
NTSB Notification Time 515
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Nov 25 2003 11:36AM
User who most recently changed record NTSB\MONR
Basic weather conditions Instrument Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N735D
NTSB Number LAX01IA066
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage Minor
Aircraft Fire In-flight
Aircraft Explosion None
Aircraft Manufacturer's Full Name Lockheed
Aircraft Model L-1011-385-1
Aircraft Series Identifier L-1011
Aircraft Serial Number 193C-1226
Certified Max Gross Weight 440000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 317
Number of Engines 3
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Dec 3 2000 12:00AM
Airframe hours since last inspection --
Airframe Hours 58217.8
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Delta Airlines Inc.
Aircraft Owner Street Address 1020 Delta Blvd.
Aircraft Owner City Atlanta
Aircraft Owner State GA
Aircraft Owner Country USA
Aircraft Owner Zipcode 30320
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code DALA
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code SAN
Departure City San Fransisco
Departure State CA
Departure Country USA
Departure Time 1910
Departure Time Zone PST
Destination Same as Local Flt --
Destination Airport Code HNL
Destination City Honolulu
Destination State HI
Destination Country USA
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred No
Date of most recent change to record Sep 15 2003 1:30PM
User who most recently changed record COOS
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --