# NTSB ANC93LA178: Piper PA-18-150, N3996Z, Prudhoe Bay, AK, September 13, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 13, 1993, 15:00 local (23:00 UTC) - Place: Prudhoe Bay, AK - Coordinates: 70.429885, -149.290527 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=70.4299&lon=-149.2905&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 30, 1994 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2428 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC93LA178 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2428/pdf - Page: https://openairdocs.org/ntsb/ANC93LA178 ## Probable cause FLUID FUEL CONTAMINATION AS A RESULT OF THE PILOT-IN-COMMANDS IMPROPER PREFLIGHT PLANNING/PREPARATION. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - nonmechanical, approach - fluid,fuel - contamination (cause) - preflight planning/preparation - improper, pilot in command (cause) - Forced landing, descent - emergency - Nose over, landing ## Analysis THE PILOT REPORTED THAT THE PLANE'S ENGINE SUDDENLY LOST A SUBSTANTIAL AMOUNT OF POWER APPROXIMATELY TWO HUNDRED FEET FROM THE APPROACH END OF THE REMOTE TUNDRA STRIP. THE AIRPLANE LANDED SHORT, BOUNCED, AND THE ENGINE REGAINED SOME RPM. A GO-AROUND WAS ATTEMPTED BUT THE ENGINE LOST POWER AGAIN. THE PILOT PERFORMED A FORCED LANDING NEAR THE END OF THE STRIP AND USED HEAVY WHEEL BREAKING. THE PLANE NOSED OVER ONTO ITS BACK. THE PILOT SAID THAT HE DRAINED THE PLANE'S FUEL TANKS AND ENGINE SUMPS PRIOR TO CONDUCTING THE FLIGHT AND FOUND NO CONTAMINATION. NO FURTHER PROBLEMS WERE EXPERIENCED WITH THE ENGINE DURING THE APPROXIMATE 8 HOUR FERRY FLIGHT TO ANCHORAGE, ALASKA. NO ABNORMALITIES WITH THE ENGINE WERE NOTED DURING THE TEARDOWN EXAMINATION. THE PILOT SAID THAT THE LOSS OF POWER WAS PROBABLY CAUSED BY THE ENGINE INGESTING A SMALL AMOUNT OF WATER. ## Factual narrative On September 13, 1993, at 1500 Alaska daylight time, a tundra tire wheel equipped Piper Pa-18-150 airplane, N3996Z, owned and operated by the pilot-in-command, doing business as Arctic Wilderness Lodge, crashed on a remote tundra strip approximately 80 miles south of Prudhoe Bay, Alaska. The commercial pilot, the sole occupant, was not injured, and the airplane sustained substantial damage. At the time of the mishap, the airplane was being operated under 14 CFR Part 91 as a business flight. The flight last departed Happy Valley Lodge, approximately 7 miles from the mishap site, near the Toolik River. The pilot was attempting to land at the site to recover moose meat belonging to a hunting party. A company VFR flight plan was in effect and visual meteorological conditions prevailed. The pilot told the NTSB Investigator-in-Charge, during a phone conversation on the afternoon of September 14, 1993, that approximately 200 feet from the approach end of the landing strip, the engine lost power and "sputtered as if someone had pulled the fuel mixture control". He pumped the engine throttle control several times but got only a minimal increase in RPM's. Upon touching down short of the landing strip, the airplane bounced and the engine regained additional RPM's. He then attempted to go-around but the engine lost power again. The pilot reported that the subsequent forced landing near the end of the strip required the use of heavy wheel breaking which resulted in the plane nosing over onto its back. The pilot said that he drained the wing and engine fuel sumps prior to commencing the flight, about one hour earlier, and observed no contamination. At the time of the mishap, he believed that the left and right wing fuel tanks were each one quarter full and the belly tank contained 4 to 5 gallons of 100LL aviation gasoline. The plane was sufficiently repaired and ferried to the Merrill Field Airport in Anchorage, Alaska, approximately eight flight hours away. During the flight, no problems were experienced with the powerplant. A subsequent tear down and inspection of the engine, including the carburetor, found nothing that would have contributed to the power interruption. The pilot reported that given that there were no problems found with the engine, the interruption in power was probably caused by the engine injesting a small amount of water. ## Aircraft - Registration: [N3996Z](https://openairdocs.org/aircraft/N3996Z), registered now, S/N 18-7945, built 1963 (OpenAirDocs) - Reported make and model: PIPER PA-18-150 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-1806 - Airframe hours: 6200 - Engines: LYCOMING O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: David F. Neel - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 25, 1993, 78 hours before - Departed: HAPPY VALLEY, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; commercial; airplane ratings: single-engine land, single-engine sea; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 3,300 total, 2,250 in this make and model, 3,300 as pilot in command, 210 in the last 90 days, 32 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 99 statute miles - Lowest ceiling: none - Temperature: 45 °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 19930913037829A](https://openairdocs.org/incident/19930913037829A), Sep 13, 1993: Piper PA18150, Prudhoe Bay, AK, Substantial damage. Engine intermittant landing at remote strip. Over strip. Slipped over. Beleive water in fuel. ## Other investigations on N3996Z (3) 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 ANC05CA050](https://openairdocs.org/ntsb/ANC05CA050), Mar 19, 2005: Piper PA-18 (N3996Z), False Pass, AK, substantial damage. Probable cause: The pilot's inadequate compensation for the wind conditions during the initial climb after takeoff, which resulted in a collision with the ground and subsequent nose over. Factors contributing to the… - [NTSB FTW71FRA24](https://openairdocs.org/ntsb/FTW71FRA24), Oct 25, 1970: Piper PA-18 (N3996Z), Conroe, TX, substantial damage - [NTSB UNK65X1302](https://openairdocs.org/ntsb/UNK65X1302), Jan 17, 1965: Piper PA18 (N3996Z), Del Rio, TX, 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.