Boeing 737-222 incident near Oklahoma City, Oklahoma, July 15, 1992
On July 15, 1992 at about 9:15 pm local time, a Boeing 737-222, registered N12235, was involved in an incident near Oklahoma City, Oklahoma. It was a flight of an unrecorded kind under scheduled airline rules (Part 121). No one was hurt; 88 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
HYDRAULIC FLUID EXHAUSTION DUE TO THE CHAFED 'A' SYSTEM HYDRAULIC LINE AND THE IMPROPER INSTALLATION BY UNKNOWN MAINTENANCE PERSONNEL OF THE 'B' SYSTEM LINE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 15, 1992 · about 9:15 pm local time
- Place
- Oklahoma City, Oklahoma · map
- Type
- Incident
- Injuries
- No one was hurt; 88 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 737-222 · all 737-222s on the register
- Registration
- N12235 · no longer on the register · serial 19758
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
THE AIRPLANE EXPERIENCED A DUAL HYDRAULIC SYSTEM FAILURE DURING FINAL APPROACH. THE CAPTAIN ELECTED TO GO AROUND AND LAND AT A NEARBY MILITARY AIRPORT THAT HAD LONGER RUNWAYS. THE LANDING WAS UNEVENTFUL. INVESTIGATION REVEALED THAT A HOLE HAD BEEN CHAFED THROUGH A RETURN LINE IN THE 'A' HYDRAULIC SYSTEM AT A BRACKET IN THE LEFT WHEEL WELL AREA. IT WAS ALSO DETERMINED THAT AN 'A' SYSTEM AND A 'B' SYSTEM RETURN LINE HAD BEEN CROSS CONNECTED IN THE AREA OF THE NO. 1 PYLON. THE CROSS CONNECTED LINES ALLOWED THE 'B' SYSTEM FLUID TO TRANSFER INTO THE 'A' SYSTEM AND VENT OVERBOARD. BOTH HYDRAULIC SYSTEMS, INDICATIONS AND READINGS, AND TESTS WERE NORMAL UNTIL THE HOLE WAS CHAFED THROUGH THE 'A' SYSTEM LINE. A MAINTENANCE RECORD REVIEW COULD NOT DETERMINE AT WHAT POINT IN TIME THE LINES HAD BEEN REVERSED.
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; instrument: airplane
- Flight time: 13,000 hours in all; 800 in this make and model; 120 in the last 90 days; 40 in the last 30 days
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 41,106 hours
- Last inspection: continuous airworthiness programme, February 3, 1992; 74 hours since
- Maximum gross weight: 109,000 lb
- Seats: 107
- Landing gear: retractable
- Engine: P&W JT8D-9 (turbofan); 0 hours total
- Operator: Continental Airlines, INC.
The flight
- Departed from: DEN Denver CO at 7:15 pm
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 5 | |||
| Passengers | 83 |
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.