Boeing 737-300-3H4 incident near Ontario, California, April 30, 1996
On April 30, 1996 at about 9:36 pm local time, a Boeing 737-300-3H4, registered N331SW, suffered minor damage in an incident near Ontario, California (Ontario International airport). It was a flight of an unrecorded kind under scheduled airline rules (Part 121). No one was hurt; 132 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The repair facility's improper assembly of the landing gear oleo strut during overhaul.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 30, 1996 · about 9:36 pm local time
- Place
- Ontario, California · Ontario International · map
- Type
- Incident
- Injuries
- No one was hurt; 132 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 737-300-3H4 737-300-3H · all 737-300-3H4s on the register
- Registration
- N331SW · registry record · serial 23695
- Damage
- Minor damage
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported an unresolved main landing gear problem and orbited the area performing normal emergency gear extension procedures without success. The pilot performed low 'G' maneuvers and touch-and-go landings in an attempt to lower the left main gear. The pilot diverted to another airport where an emergency landing was made with minor damage and no injuries. The landing gear was removed and disassembled. The upper bearing carriers and bearing half shells were found out of position in the upper portion of the oleo strut. The subsequent over extension of the strut was a result of the gradual breakup of the bearings and bearing carriers due to improper/incompatible wear surfaces from the repair facility's improper assembly at overhaul. The compression/extension measurements after installation were not required.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 12,500 hours in all; 5,600 in this make and model; 240 in the last 90 days; 80 in the last 30 days; 8,000 as pilot in command; 1,500 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 26,697 hours
- Last inspection: continuous airworthiness programme, April 16, 1996; 129 hours since
- Maximum gross weight: 130,000 lb
- Seats: 145
- Landing gear: retractable
- Engine: Ge CFM-56 (turbofan); 0 hours total
The flight
- Departed from: LAS Las Vegas NV at 11:00 pm
- Destination: BUR Burbank CA
- Flight plan: IFR
- Runway 26R, 12,200 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 230° at 10 knots
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 90°F (32°C), dew point 0°F (-18°C)
- Observation at 10:50 pm from ONT
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 5 | |||
| Passengers | 127 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.