Piper PA-23-250 accident near Boscobel, Wisconsin, September 20, 1991
On September 20, 1991 at about 9:23 pm local time, a Piper PA-23-250, registered N915PM, was substantially damaged in an accident near Boscobel, Wisconsin (Boscobel airport). It was a flight of an unrecorded kind under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
IMPROPER REMEDIAL ACTION BY THE PILOT-IN-COMMAND (PIC), AND INADEQUATE MONITORING BY THE DESIGNATED PILOT EXAMINER (DPE) DURING A SIMULATED EMERGENCY PROCEDURE. FACTORS RELATED TO THE ACCIDENT WERE: THE LOSS OF POWER IN ONE ENGINE DUE TO AN UNDETERMINED REASON, AND OBSTRUCTIONS IN THE EMERGENCY LANDING AREA THAT REQUIRED A DELAY OF GEAR EXTENSION IN ORDER TO REACH A CLEAR AREA.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 20, 1991 · about 9:23 pm local time
- Place
- Boscobel, Wisconsin · Boscobel · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-23-250 · all PA-23-250s on the register
- Registration
- N915PM · registry record · serial 27-7305030
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
PURPOSE OF THE FLT WAS FOR THE PIC TO GET A MULTI-ENG (ADD-ON) RATING. DRG A 2 ENG GO-ARND, THE DESIGNATED PLT EXAMINER (DPE) SIMULATED AN ENG FAILURE BY RETARDING THE L THROTTLE. SOON THEREAFTER, THE AIRSPEED DECREASED & THE PIC ADZD THE DPE THAT HE WAS UNABLE TO MAINT ALT OR ATTITUDE. THE L THROTTLE WAS RE-ADVANCED WITH NO APPARENT EFFECT. THE PIC WAS UNABLE TO RESTORE PWR IN THE L ENG & RELINQUISHED THE FLT CTLS TO THE DPE. THE ACFT WAS PREPARED FOR AN APCH TO THE ARPT. WITH THE L ENG (& HYD SYS) INOP, THE PIC USED THE MANUAL HAND PUMP TO OPER THE GEAR & FLAPS (AFTER ASSURING THE ACFT WOULD CLR OBSTACLES). HE CONTD PUMPING, BUT THE ACFT WAS FORCED TO LND SHORT OF THE RWY & THE NOSE GEAR COLLAPSED DRG TCHDWN BFR IT WAS FULLY EXTDD. THE WING FLAPS WERE FND EXTDD. THE LNDG GEAR & WING FLAPS OPERD FM THE SAME HYD SYS; EITHER COULD HAVE BEEN ACTUATED INDEPENDENTLY OF THE OTR. THE HYD SYS WAS BUILT SO THAT WHEN THE GEAR & FLAPS WERE ENGAGED AT THE SAME TIME, THE GEAR WOULD COMPLETE ITS OPN BFR THE FLAPS OPERD. NO REASON FND FOR LOSS OF PWR IN L ENG.
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: private
- Ratings: single-engine land
- Flight time: 544 hours in all; 38 in this make and model; 2 in the last 30 days; 450 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 2,594 hours
- Last inspection: annual inspection, August 20, 1991; 13 hours since
- Maximum gross weight: 5,200 lb
- Seats: 6
- Landing gear: retractable
- Engine: Lycoming TIO-540 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 1, 3,710 ft by 58 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 54°F (12°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.