Stinson 108-3 accident near Coleman, Michigan, September 1, 2020
On September 1, 2020 at about 3:00 pm local time, a 1947 Stinson 108-3, registered N909C, was substantially damaged in an accident during enroute (cruise) near Coleman, Michigan. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s improper installation of the generator drive gear, which resulted in a total loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 1, 2020 · about 3:00 pm local time
- Place
- Coleman, Michigan · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Stinson 108-3, built 1947 · all 108-3s on the register
- Registration
- N909C · registry record · serial 108-3909
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot had been flying for about 45 minutes when the airplane experienced a total loss of engine power. The pilot performed a forced landing onto a field. The airplane nosed over and sustained substantial damage to the fuselage and empennage. Postaccident examination of the engine revealed that the single generator drive gear for the ignition system had separated into several pieces. The drive gear shaft installation called for a castellated nut with a cotter pin to retain the drive gear, but the cotter pin had not been installed and allowed the nut to back off, which ceased ignition to the engine. The generator was installed by the pilot, who did not hold a mechanic certificate, during his overhaul of the engine. The pilot stated that he performed the overhaul of the engine and installation of the generator under the supervision of a mechanic with an airframe and powerplant ratings. No other mechanical anomalies with the engine were noted.
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
What happened, in order
- Powerplant sys/comp malf/fail during enroute (cruise) defining event
- Loss of engine power (total) during enroute (cruise)
- Collision with terrain or object (not controlled flight into terrain) during landing
- Aircraft maintenance event during prior to flight
- Aircraft inspection event during prior to flight
The NTSB's findings
- Aircraft › Aircraft power plant › Ignition system › Magneto/distributor › Failure
- Personnel issues › Task performance › Inspection › Post maintenance inspection › Maintenance personnel
- Personnel issues › Task performance › Maintenance › Installation › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 148 hours in all; 16 in this make and model; 77 as pilot in command
- Last flight review: October 29, 2018
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 1,804 hours
- Last inspection: annual inspection
- Maximum gross weight: 2,401 lb
- Seats: 4
- Landing gear: fixed
- Engine: Franklin 6A4165 SERIES (piston); 1,804 hours total
The flight
- Departed from: 53W Remus MI at 2:00 pm
- Destination: 53W Remus MI
- Flight plan: none
Weather at the time
- Light: daylight
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on June 10, 2022. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 2 | Record of Conversation - FAA | PDF, 1 page | View Download |
| 3 | Photo Log | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.