Boeing 747-122 N4712U
12 June 1984 · San Francisco, California, United States · No injuries
Summary
On 12 June 1984 at about 04:30 local time, a Boeing 747-122 registered N4712U, operated by United Airlines, was involved in an incident near San Francisco, California, United States. 4 people were on board and nobody was injured. The aircraft was slightly damaged. No probable cause statement is available for this record.
The record
- Date
- at 04:30
- Classification
- Incident
- Location
- San Francisco, California, United States
- Coordinates
- 37.6094, -122.3795
- Aircraft
- Boeing 747-122
- Registration
- N4712U
- Category
- Airplane
- Engines
- 4
- Operator
- United Airlines
- Operating rule
- Part 121: Air Carrier
- Purpose of flight
- Unknown
- Phase of flight
- Not recorded
- Route
- Honolulu → San Francisco
- Aircraft damage
- Minor
- Weather
- VMC
- Light
- Dusk
- NTSB number
- LAX84IA350
People
Nobody was injured.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 4 | 0 | 0 | 0 | 4 |
Probable cause
The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.
Nothing about the cause is stated here that is not in the source record.
Read the full NTSB narrative
JUST INSIDE THE OUTER MARKER, A 'LOUD BANG' WAS HEARD & LEFT AILERON INPUT WAS NEEDED TO CONTROL ACFT HEADING. THE LANDING WAS MADE WITHOUT INCIDENT UNTIL THE FLAPS WERE RAISED WHILE TAXIING & THE FLT ENGINEER REPORTED A #4 HYDRAULIC SYSTEM FAILURE. THE CAPT LOST BRAKES AND HAD TO UTILIZE STANDBY BRAKES. AT THIS TIME A SPLIT FLAP INDICATION WAS OBSERVED. INSPECTION REVEALED FLAP TRACK FRACTURED APRX 6 INCHES AFT OF THE FORWARD ATTACH POINT. THE FRACTURE INITIATEDON OUTBOARD FLANGE #1 BOLTHOLE WALL BECAUSE OF PITTING CORROSION. A PORTION OF THE FORE FLAP & A SMALL WING PANEL SEPARATED FROM THE ACFT. DURING FLAP RETRACTION AFTER LANDING, THE TRANSMISSION BALL NUT JAMMED. THE DRIVE TORQUE TUBE FRACTURED AT THIS TIME AND THE BROKEN END OF THE ROTATING TORQUE TUBE DAMAGED HYDRAULIC LINES, CAUSING A LOSS OF HYDRAULIC FLUID. AN ALERT SERVICE BULLETIN WAS ISSUED BY BOEING AFTER THIS INCIDENT & UNITED AIRLINES INITIATED A FLEET WIDE INSPECTION.
Quoted verbatim from the NTSB record.
Other Boeing 747 accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 20 Dec 1984 | Boeing 747-200 | New Orleans, Louisiana, United States | - | No injuries | - |
| 18 Jan 1984 | Boeing 747-230 | Jamaica, New York, United States | Lufthansa Airlines | Serious injuries | - |
| 14 Apr 1984 | Boeing 747-121 | Martinique | Pan American (Paaa) | No injuries | - |
| 2 Nov 1984 | Boeing 747-131 | Los Angeles, California, United States | - | No injuries | - |
| 29 Sep 1984 | Boeing 747-200B | Seattle, Washington, United States | - | No injuries | - |
| 12 May 1984 | Boeing 747 | Los Angeles, California, United States | - | No injuries | - |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 28 Jan 1984 | Cessna 401A | San Francisco, California, United States | - | No injuries | - |
| 4 Aug 1984 | Eipper QUICKSILVER MX | Thousand Oaks, California, United States | - | Serious injuries | - |
| 5 Feb 1984 | Hughes 500C (369HS) | San Diego, California, United States | - | Serious injuries | - |
| 5 Feb 1984 | Cessna 180J | Hayward, California, United States | - | Serious injuries | - |
| 14 Jul 1984 | Piper PA-31T | Concord, California, United States | - | Fatal | 6 |
| 5 Feb 1984 | Cessna 150M | Fremont, California, United States | Fremont Flying Service | No injuries | - |