British Aerospace ATP incident near Mosinee, Wisconsin, February 26, 1994
On February 26, 1994 at about 4:23 am local time, a British Aerospace ATP, registered N854AW, suffered minor damage in an incident near Mosinee, Wisconsin. It was a flight of an unrecorded kind under scheduled airline rules (Part 121). 2 people had minor injuries; 16 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the inadequate design of the PBSI electrical switch(es), and the operator's failure to expeditiously implement corrective Service Bulletins.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 26, 1994 · about 4:23 am local time
- Place
- Mosinee, Wisconsin · map
- Type
- Incident
- Injuries
- 2 people had minor injuries; 16 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- British Aerospace ATP
- Registration
- N854AW · no longer on the register · serial 2028
- 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 FLIGHT CREW SAW SMOKE IN THE COCKPIT WHILE DESCENDING FROM CRUISE AND DECLARED AN EMERGENCY. THE COPILOT DISCOVERED THE SOURCE OF THE SMOKE TO BE A RED-HOT PUSH BUTTON SELECTOR INDICATOR (PBSI) SWITCH FOR THE FLIGHT IDLE BAULK TEST. HE DISCHARGED A PORTABLE FIRE EXTINGUISHER ON THE SWITCH AND THE SMOKE STOPPED. THE SWITCH WAS SUBSEQUENTLY REMOVED BY MAINTENANCE PERSONNEL AND FOUND TO SCORCHED AND MELTED. ADJACENT WIRING WAS ALSO HEAT DAMAGED. THE MANUFACTURER HAD PREVIOUSLY ISSUED TWO SERVICE BULLETINS WHICH DEALT WITH PBSI SWITCH MALFUNCTIONS ASSOCIATED WITH WATER INGRESS TO THE COCKPIT IN THE VICINITY OF THE SWITCHES. THE OPERATOR HAD NOT COMPLIED WITH THE VOLUNTARY SERVICE BULLETINS AT THE TIME OF THE INCIDENT.
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: 4,300 hours in all; 300 in this make and model
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 50,550 lb
- Seats: 68
- Landing gear: retractable
- Engine: P&W PW126A (turboprop); 0 hours total
- Not recorded
The flight
- Departed from: ORD Chicago IL at 2:45 am
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: night, bright
- Wind: from 360° at 10 knots
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 3:00 am from CWA
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 4 | |||
| Passengers | 2 | 12 |
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.