# NTSB ANC86FA085: Piper L-4H, N58988, Anchorage, AK, June 21, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: June 20, 1986, 19:30 local (Jun 21, 1986, 03:30 UTC)
- Place: Anchorage, AK
- Coordinates: 61.160388, -149.990737 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=61.1604&lon=-149.9907&mi=10
- Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4597
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC86FA085
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4597/pdf
- Page: https://openairdocs.org/ntsb/ANC86FA085

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, descent - emergency
  - engine assembly - inoperative (cause)
  - maintenance,inspection - inadequate, pilot in command (cause)
  - maintenance,lubrication - inadequate, pilot in command (cause)
  - operation with known deficiencies in equipment - improper, pilot in command (cause)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)
  - terrain condition - ditch (contributing factor)
  - weather condition - tailwind (cause)

## Analysis

THE PILOT/MECHANIC STATED THE ENGINE OIL PRESSURE GAUGE BEGAN FLICKERING, SO HE ELECTED TO LAND AND DURING THE DESCENT THE ENGINE FAILED. HE LANDED DOWNWIND IN 20 KNOT WINDS AND DURING THE LANDING ROLL, ACROSS TUNDRA/MUD THE AIRPLANE'S WHEELS STRUCK A LARGE WATER FILLED HOLE AND NOSED OVER. POST ACC EXAM OF THE ACFT REVEALED THAT THE BOTTOM OF THE FUSELAGE WAS COVERED WITH OIL. THE OIL BREATHER TUBE HAD AN OIL CAN WIRED TO IT. THE PLT DID HIS OWN MAINTENANCE WORK. THE OIL WAS BEING BLOWN OUT THRU THE BREATHER TUBE. SINCE THE ACFT WAS UPSIDE DOWN ANY REMAINING OIL HAD DRAINED OUT. THE PLT WAS OPERATING THE ACFT KNOWING THAT THE LUBRICATING SYS WAS IMPROPER.

## Aircraft

- Registration: [N58988](https://openairdocs.org/aircraft/N58988), registered now, S/N 12097 (OpenAirDocs)
- Reported make and model: PIPER L-4H
- Registry model: [Piper L-4H](https://openairdocs.org/model/piper-l-4h) (registry code 7100518) (OpenAirDocs)
- Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 12097
- Airframe hours: 1900
- Engines: CONTINENTAL C90-8F 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Bob Olmstead
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 20, 1985, 50 hours before
- Departed: MOOSE POINT, AK
- Destination: Z41, ANCHORAGE, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 612 total, 584 in this make and model, 126 as pilot in command, 15 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 160° at 20 knots, gusting 30
- Visibility: 90 statute miles
- Lowest ceiling: 2,000 ft broken
- Temperature: 55 °F, dew point 43 °F
- Altimeter: 29.00 inHg

## 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 19860620027009A](https://openairdocs.org/incident/19860620027009A), Jun 20, 1986: Piper L4, Anchorage, AK, Substantial damage. Oil was depleted, engine quit en route. Flipped over on tundra. Excessive blowby of oil through breather tube.

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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