# NTSB ANC94LA116: Piper PA-18, N4478A, Skwentna, AK, August 29, 1994

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 29, 1994, 15:00 local (23:00 UTC)
- Place: Skwentna, AK
- Coordinates: 59.850803, -154.559677 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=59.8508&lon=-154.5597&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report May 9, 1995
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 2548
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC94LA116
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2548/pdf
- Page: https://openairdocs.org/ntsb/ANC94LA116

## Probable cause

THE PILOT'S SELECTING A GRAVEL BAR FOR A NORMAL LANDING.  A FACTOR WAS THE SOFT SPOT IN THE GRAVEL BAR.

## Sequence of events

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

- Nose over, landing - roll
  - terrain condition - soft (contributing factor)
  - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause)

## Analysis

THE PILOT LANDED THE AIRPLANE ON A GRAVEL BAR.  DURING THE LANDING ROLL HE WAS APPLYING BRAKE PRESSURE.  THE WHEELS HIT A SOFT SPOT IN THE GRAVEL AND THE AIRPLANE NOSED OVER.

## Factual narrative

On August 29, 1994, at 1500 Alaska daylight time, a wheel equipped Piper PA-18 airplane, N4478A, registered to and operated by Henry J. Orth of Anchorage, Alaska, nosed over during the landing roll on a gravel bar located at the confluence of the Hartman River and South Fork of the Kuskokwim River.  The personal flight, operating under 14 CFR Part 91, departed a field site for a local hunting flight.  No flight plan was filed and visual meteorological conditions prevailed.  The pilot, the sole occupant, was not injured and the airplane received substantial damage.

According to the pilot he landed on a gravel bar and during the landing roll, while applying brake pressure, the airplane's wheels hit a soft spot and the airplane nosed over.

## Aircraft

- Registration: [N4478A](https://openairdocs.org/aircraft/N4478A), registered now, S/N 18-4835, built 1956 (OpenAirDocs)
- Reported make and model: PIPER PA-18
- Registry model: [Piper PA-18A 150](https://openairdocs.org/model/piper-pa-18a-150) (registry code 7101837) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-4835
- Airframe hours: 5445
- Engines: Lycoming O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Orth, Henry J.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 5, 1993, 49 hours before
- Departed: WISILLA, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; private; airplane ratings: single-engine land, single-engine sea; medical: class 3, valid medical--no waivers/lim.; seat: front; flight hours: 2,359 total, 1,735 in this make and model, 2,359 as pilot in command, 21 in the last 90 days, 14 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 99 statute miles
- Lowest ceiling: none
- Temperature: 50 °F

## 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 19940829024019A](https://openairdocs.org/incident/19940829024019A), Aug 29, 1994: Piper PA18A150, Farewell, AK, Substantial damage. Nosed over landing on a gravel bar. Wheels had hit a soft spot.

## Other investigations on N4478A (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 UNK64X3236](https://openairdocs.org/ntsb/UNK64X3236), Aug 6, 1964: Piper PA18A (N4478A), Mendota, IL, 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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