Aero Commander S-2R accident near Grangeville, Idaho, April 15, 1991
On April 15, 1991 at about 1:00 am local time, a Aero Commander S-2R, registered N5539X, was destroyed in an accident near Grangeville, Idaho. It was a ferry flight under general aviation rules (Part 91). 1 person was killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
THE IMPROPER DECISION BY THE PILOT TO CONTINUE VFR FLIGHT IN IMC WEATHER CONDITIONS IN MOUNTAINOUS TERRAIN, RESULTING IN PILOT DISORIENTATION AND INADVERTENT FLIGHT INTO A BOX CANYON. FACTORS RELATING TO THE ACCIDENT WERE THE RAIN SHOWERS AND LOW CEILING WEATHER CONDITIONS, AND THE BOX CANYON IN MOUNTAINOUS TERRAIN.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 15, 1991 · about 1:00 am local time
- Place
- Grangeville, Idaho · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Aero Commander S-2R · all S-2Rs on the register
- Registration
- N5539X · no longer on the register · serial 1739
- Damage
- Destroyed
- Flight
- Ferry flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE FLT ENCOUNTERED LOW CEILINGS AND RAIN SHOWERS ON A VFR FLT THRU REMOTE HIGH ALT MT. TERRAIN. THE PILOT INADVERTANTLY ENTERED A BOX CANYON AND ATTEMPTED TO REVERSE COURSE. THE ACFT IMPACTED TERRAIN ON THE SIDE OF THE CANYON AT 7100 FT MSL.
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: commercial pilot
- Ratings: single-engine land
- Flight time: 6,800 hours in all
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 6,490 hours
- Last inspection: annual inspection, March 21, 1991
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R1340 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: SMN Salmon ID at 9:45 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 150° at 4 knots
- Visibility: 15 statute miles
- Sky: overcast at 4,500 ft; not recorded
- Temperature: 39°F (4°C), dew point 19°F (-7°C)
- Altimeter: 28.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
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.