ASN logo
Last updated: 20 February 2019
Status:Final
Date:Friday 24 February 1989
Time:ca 02:00
Type:Silhouette image of generic B741 model; specific model in this crash may look slightly different
Boeing 747-122
Operator:United Airlines
Registration: N4713U
C/n / msn: 19875/89
First flight: 1970-10-20 (18 years 4 months)
Total airframe hrs:58814
Cycles:15027
Engines: 4 Pratt & Whitney JT9D-7A
Crew:Fatalities: 0 / Occupants: 18
Passengers:Fatalities: 9 / Occupants: 337
Total:Fatalities: 9 / Occupants: 355
Aircraft damage: Substantial
Aircraft fate: Repaired
Location:near Hawaii (   Pacific Ocean)
Phase: En route (ENR)
Nature:International Scheduled Passenger
Departure airport:Honolulu International Airport, HI (HNL/PHNL), United States of America
Destination airport:Auckland International Airport (AKL/NZAA), New Zealand
Flightnumber:UA811
Narrative:
United Airlines Flight 811, a Boeing 747-122, N4713U, took off from Honolulu (HNL), Hawaii at 01:33 local time, bound for Sydney, Australia, with an intermediate stop at Auckland, New Zealand. The initial climb passed through an area of thunderstorms, so the captain elected to keep the seat belt sign on. As the aircraft was climbing, between 22,000 and 23,000 feet, explosive decompression was experienced. An emergency was declared at approximately 02:20 HST. The captain initiated a 180-degree left turn to avoid a thunderstorm and proceeded toward HNL. The forward lower lobe cargo door had opened in flight, taking with it a large portion of the forward right side of the cabin fuselage. The starboard side engines (no.3 and 4) were damaged and had to be shut down. Parts of the leading and trailing edge flaps where also damaged resulting in the crew electing to use only 10-degrees trailing edge flaps for landing (a non-normal configuration). This resulted in the aircraft having to land at a higher speed than it would under normal conditions. The aircraft was cleared to land at HNL runway 8L. At 02:34 HST, Honolulu tower was notified by the flight crew that the airplane was stopped and an emergency evacuation had commenced on the runway. During the decompression, nine passengers had been ejected from the airplane and lost at sea.

Probable Cause:

PROBABLE CAUSE: "The sudden opening of the forward lower lobe cargo door in flight and the subsequent explosive decompression. The door opening was attributed to a faulty switch or wiring in the door control system which permitted electrical actuation of the door latches toward the unlatched position after initial door closure and before takeoff. Contributing to the cause of the accident was a deficiency in the design of the cargo door locking mechanisms, which made them susceptible to deformation, allowing the door to become unlatched after being properly latched and locked. Also contributing to the accident was a lack of timely corrective actions by Boeing and the FAA following a 1987 cargo door opening incident on a Pan Am B-747."

Accident investigation:
cover
Investigating agency: NTSB
Status: Investigation completed
Duration: 3 years
Accident number: NTSB/AAR-92/02
Download report: Final report

Classification:
Fuselage failure
Forced landing on runway

Sources:
» NTSB/AAR-92/02


Follow-up / safety actions

NTSB issued 17 Safety Recommendations

Show all...

Photos

photo of Boeing 747-122 N4713U
photo of Boeing 747-122 N4713U
photo of Boeing 747-122 N4713U
photo of Boeing 747-122 N4713U
photo of Boeing 747-122 N4713U
photo of Boeing 747-122 N4713U
Add your photo of this accident or aircraft
 

Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Honolulu International Airport, HI to Auckland International Airport as the crow flies is 7046 km (4404 miles).
Accident location: Global; accuracy within tens or hundreds of kilometers.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
languages: languages

Share