- Date
- October 18, 1989, 00:15 local (06:15 UTC)
- Place
- Monte Vista, CO
- Injuries
- 1 minor, 102 uninjured
- Damage
- Minor damage
- Phase of flight
- Enroute
- Aircraft
- N922RWMcdonnell Douglas DC-9
- Weather
- Visual (VMC) · Night/dark
- Status
- Completed · report January 8, 1991
- Report
- Approved by Office Director
- Safety recommendations
- Yes
- Case key
- 17849
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.
On this page
Probable cause
The poor inflight planning and decisions made by the flight crew following the failure of the number two generator constant speed drive unit. Contributing factors to the accident were the failure of the no. 2 generator constant speed drive unit and the crew's inadvertent shut down of the wrong generator which resulted in a complete loss of electrical power.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
While in cruise at FL350 the no. 2 generator constant speed drive (csd) failed and the crew inadvertently disconnected the no. 1 generator csd. Attempts to start the APU above the start envelope were made but aborted due to a hot start. A descent was made on emerg electrical power and a landing was made at an arpt which was inadequate for the acft. The crew chose to make a no flap apch and to lower landing gear by emerg method when both systems were operable by normal means. This decision was influenced by the lack of landing gear and flap position indicators when the acft is operated on battery power. The landing speed was fast and the acft departed the end of the rwy damaging the landing gear and the no. 1 engine. The crew failed to manually depressurize the acft and the evacuation was delayed until a knowledgeable passenger went to the cockpit and depressurized the acft. The operators acft operating manual did contain APU starting procedures but not an APU start envelope chart.
Aircraft
- Registration
- N922RW
- Reported as
- Mcdonnell Douglas DC-9
- Category
- Airplane
- Serial number
- 47182
- Airframe hours
- 61,931
- Engine
- P&W JT8D, 17,000 lbs thrust, turbo fan
- Damage
- Minor damage
- Flight
- Part 121
- Registered owner
- Northwest Airlines
- Airworthiness certificate
- Standard, Transport
- Last inspection
- Continuous airworthiness · October 13, 1989 · 68 hours before
- Departed
- MSP · Minneapolis, MN
- Destination
- PHX · Phoenix, AZ
- Flight plan
- IFR
- Airport
- 08V · Monte Vista, runway 2, 6,000 × 60 ft, asphalt
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 46
- Certificate
- Airline transport
- Airplane ratings
- Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 15,730 total · 12,335 in this make and model · 6,500 as pilot in command · 176 in the last 90 days · 70 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Night/dark
- Wind
- 150° at 8 knots
- Visibility
- 15 statute miles
- Lowest ceiling
- 3,500 ft overcast
- Temperature
- 37 °F
- Altimeter
- 30.00 inHg
- Observed at
- PUB, 100 nm away