Boeing 737-222 incident near Denver, Colorado, September 19, 1990
On September 19, 1990 at about 5:00 pm local time, a Boeing 737-222, registered N9044U, was involved in an incident near Denver, Colorado (Stapleton Intl airport). It was a flight of an unrecorded kind under scheduled airline rules (Part 121). 2 people had minor injuries; 94 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE FAILURE OF THE FLIGHT CREW TO FOLLOW EMERGENCY PROCEDURES/DIRECTIVES. FACTORS WERE THE FAILURE OF THE AIRCRAFT ELECTRICAL SYSTEM (RELAYS) AND THE FAILURE OF THE COMPANY TO PROVIDE A JETWAY OPERATOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 19, 1990 · about 5:00 pm local time
- Place
- Denver, Colorado · Stapleton Intl · map
- Type
- Incident
- Injuries
- 2 people had minor injuries; 94 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 737-222 · all 737-222s on the register
- Registration
- N9044U · no longer on the register · serial 19550
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
SHORTLY AFTER PUSHBACK IT WAS NOTICED THAT THE #2 ENG DOOR 2 RIGHT HANDLE WAS NOT FLUSH. THE ENG WAS SHUT DOWN AND GROUND MAINT PERSONNEL CLOSED THE DOOR FROM THE OUTSIDE. THE CABIN THEN BEGAN TO FILL WITH DENSE SMOKE. THE CAPTAIN, USING RADIO AND AN OPEN WINDOW, WAS UNSUCCESSFUL IN GETTING A JETWAY TO THE AIRPLANE, AND THE CREW AND PAX EXITED USING SLIDES. IT WAS LATER DETERMINED THAT THE BATTERY BUSS RELAY (R1) AND BATTERY TRANSFER RELAY (R2) HAD FAILED. THE AIRPLANE HAD BEEN PUSHED BACK AT GATE B-8, AND HAD RECEIVED CLEARANCE TO GATE B-20 FOR THE EVACUATION. THERE WAS NO JETWAY OPERATOR PRESENT, AND GROUND PERSONNEL ARE NOT CROSS-TRAINED TO OPERATE A JETWAY. WHEN THE #2 ENG WAS SHUT DOWN, THE ELECTRICAL TRANSFER SYSTEM PICKED UP THE LOAD. THE FLIGHTCREW DID NOT POWER THE RIGHT BUS FROM THE APU.
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; instrument: airplane
- Flight time: 17,500 hours in all; 1,119 in this make and model; 123 in the last 90 days; 13 in the last 30 days; 10,000 as pilot in command
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 110,000 lb
- Seats: 113
- Landing gear: retractable
- Engine: P&W (turbojet); 0 hours total
- Operator: United Airlines
The flight
- Destination: ICT Wichita KS
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 030° at 5 knots
- Visibility: 7 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 5 | |||
| Passengers | 2 | 89 |
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.