# NTSB ANC91LA112: Pilatus Porter PC-6/350, N4913, Yakutat, AK, July 29, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 29, 1991, 15:10 local (23:10 UTC)
- Place: Yakutat, AK
- Coordinates: 59.509582, -139.709701 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=59.5096&lon=-139.7097&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 10, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5590
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91LA112
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5590/pdf
- Page: https://openairdocs.org/ntsb/ANC91LA112

## Probable cause

THE FUEL CONTAMINATION AND THE PILOT'S INADEQUATE PREFLIGHT. CONTRIBUTING TO THE ACCIDENT WAS THE SOFT SAND BAR.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, cruise
  - fuel system,tank - contamination (cause)
  - aircraft preflight - inadequate, pilot in command (cause)
  - fuel system,line - water (cause)
- Forced landing, descent - emergency
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - sand bar (contributing factor)
  - terrain condition - soft (contributing factor)

## Analysis

DURING CLIMBOUT FROM THE AIRPORT, THE ENGINE QUIT AND THE PILOT MADE AN EMERGENCY LANDING ON THE BEACH.  EXAMINATION OF THE AIRPLANE ENGINE REVEALED NO MECHANICAL MALFUNCTION OR FAILURE.  EXAMINATION OF THE FUEL SYSTEM REVEALED WATER IN THE FUEL TANKS.

## Aircraft

- Registration: [N4913](https://openairdocs.org/deregistered/N4913-2023-06-10), registration cancelled 2023-06-10, S/N 545 (OpenAirDocs)
- Reported make and model: PILATUS PORTER PC-6/350 (PORTER PC-)
- Registry model: [Pilatus PC-6/350](https://openairdocs.org/model/pilatus-pc-6-350) (registry code 7090114) (OpenAirDocs)
- Category: Airplane
- Serial number: 545
- Engines: LYCOMING GSO-480-B1A6 340 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 20, 1990
- Departed: YAK, YAKUTAT, AK
- Destination: NONE, DRY BAY, AK
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; airline transport; airplane ratings: single-engine land, multi-engine sea, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 9,670 total, 320 in this make and model, 8,870 as pilot in command, 311 in the last 90 days, 66 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 12 knots
- Visibility: 3 statute miles
- Lowest ceiling: 400 ft broken
- Temperature: 55 °F, dew point 41 °F
- Altimeter: 30.00 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 19910729030499A](https://openairdocs.org/incident/19910729030499A), Jul 29, 1991: Pilats PC6350, Yakutat, AK, Substantial damage. Engine quit. Stall landed in clearing and rolled into trees. Found water in fuel.

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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