# NTSB CHI91LA184: Piper PA-28-140, N7470R, Grass Lake, MI, June 9, 1991

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 9, 1991, 14:45 local (18:45 UTC)
- Place: Grass Lake, MI
- Coordinates: 42.250637, -84.199203 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.2506&lon=-84.1992&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor, 1 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 15089
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91LA184
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15089/pdf
- Page: https://openairdocs.org/ntsb/CHI91LA184

## Probable cause

A RUPTURED OIL COOLER LINE. A FACTOR ASSOCIATED WITH THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR THE PRECAUTIONARY LANDING.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, cruise
  - lubricating system,oil hose - ruptured (cause)
  - precautionary landing - initiated, pilot in command
- In flight collision with terrain/water, landing - roll
  - terrain condition - none suitable (contributing factor)

## Analysis

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.

## Aircraft

- Registration: [N7470R](https://openairdocs.org/deregistered/N7470R-2003-11-17), registration cancelled 2003-11-17, S/N 28-22018, built 1966 (OpenAirDocs)
- Reported make and model: PIPER PA-28-140
- Registry model: [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140) (registry code 7102802) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 22-22018
- Engines: LYCOMING O-320-E2A 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Scott G. Miller
- Registered owner: Scott G. Miller
- Departed: ARB, ANN ARBOR, MI
- Destination: JXN, JACKSON, MI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; flight hours: 216 total, 192 in this make and model, 177 as pilot in command, 12 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 230° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F
- Observed at: JXN, 10 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19910609020579A](https://openairdocs.org/incident/19910609020579A), Jun 9, 1991: Piper PA28140, Grass Lake, MI, Substantial damage. Smoke in cockpit lost oil pressure. Overshot selected field for precautionary landing. Oil cooler hose had ruptured

## Other investigations on N7470R (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB CHI67F0494](https://openairdocs.org/ntsb/CHI67F0494), Feb 4, 1967: Piper PA-28 (N7470R), Charlotte, MI, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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