Piper PA-28-140 accident near Grass Lake, Michigan, June 9, 1991
On June 9, 1991 at about 6:45 pm local time, a Piper PA-28-140, registered N7470R, was substantially damaged in an accident near Grass Lake, Michigan. It was a personal flight under general aviation rules (Part 91). 2 people had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A RUPTURED OIL COOLER LINE. A FACTOR ASSOCIATED WITH THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR THE PRECAUTIONARY LANDING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 9, 1991 · about 6:45 pm local time
- Place
- Grass Lake, Michigan · map
- Type
- Accident
- Injuries
- 2 people had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-28-140 · all PA-28-140s on the register
- Registration
- N7470R · no longer on the register · serial 22-22018
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PLT SAID THAT WHILE CRUISING AT 3000 FEET MSL, HE NOTICED SMOKE IN THE COCKPIT, THEN A LOSS OF OIL PRESSURE. THE PLT REDUCED POWER TO A MINIMUM AND ELECTED TO MAKE A PRECAUTIONARY LANDING ON A HAY FIELD. OVERSHOOTING HIS INTENDED LANDING SITE, HE TRIED TO LAND IN AN ADJACENT FIELD, BUT COLLIDED WITH A FENCE, A RAILROAD RIGHT OF WAY, THEN BOUNCED AND SLID TO A STOP ON THE RAILROAD TRACKS. POST ACCIDENT INVESTIGATION REVEALED AN OIL COOLER HOSE HAD FAILED WHICH CAUSED THE LOSS OF OIL PRESSURE.
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: 216 hours in all; 192 in this make and model; 12 in the last 90 days; 4 in the last 30 days; 177 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 2,150 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-320-E2A (piston); 0 hours total
The flight
- Departed from: ARB Ann Arbor MI at 6:20 pm
- Destination: JXN Jackson MI
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 230° at 6 knots
- Visibility: 10 statute miles
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 6:35 pm from JXN, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
Other NTSB records under N7470R the same tail number, which may have belonged to a different aircraft at the time
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.