# NTSB SEA99LA048: Enstrom F-28C, N51770, Pendleton, OR, April 7, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 6, 1999, 17:30 local (Apr 7, 1999, 00:30 UTC) - Place: Pendleton, OR - Coordinates: 45.73051, -118.790153 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.7305&lon=-118.7902&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 22, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46106 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA99LA048 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46106/pdf - Page: https://openairdocs.org/ntsb/SEA99LA048 ## Probable cause A loss of power due to water contamination of the fuel. Factors include the inability of the helicopter to perform a successful autorotation immediately after takeoff. ## Analysis During takeoff from the refueling pad, the helicopter's engine lost power and the pilot attempted an autorotation. Because the aircraft did not yet have sufficient airspeed or altitude to complete a successful autorotation, it landed hard and the main rotor blades flexed downward and impacted the tail boom. It was later determined that water contamination had accidentally been transferred from a portable refueling barrel to the aircraft's fuel system during hot refueling (with engine still running). It could not be determined how water was introduced into the refueling barrel. ## Factual narrative On April 6, 1999, approximately 1730 Pacific daylight time, a main rotor blade of an Enstrom F-28C helicopter, N51770, impacted the aircraft's tail boom during an emergency landing near Pendleton, Oregon. The aircraft, which was owned and operated by General Aircraft Services, sustained substantial damage, but the commercial pilot reported that he was not injured. No flight plan had been filed for the VFR 14 CFR Part 137 aerial application flight, and there was no report of an ELT activation. According to the pilot, he had just taken off from the refueling site and was beginning to initiate a climb when the engine lost power. He attempted to autorotate to a landing, but since the aircraft had not attained sufficient airspeed or altitude to perform a successful autorotation, it hit hard and the main rotor blades flexed downward and impacted the tail boom. It was later determined that the fuel in the portable refueling barrel was contaminated with water. While the pilot kept the aircraft running during the refueling operation (hot refueling), water-contaminated fuel was transferred from the barrel to the helicopter's fuel system and remained undetected. It could not be determined how water was introduced into the barrel itself. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, takeoff - fuel system - contamination,water (cause) - Hard landing, emergency landing after takeoff - autorotation - attempted, pilot in command - autorotation - not possible (contributing factor) ## Aircraft - Registration: [N51770](https://openairdocs.org/aircraft/N51770), registered now, S/N 445 (OpenAirDocs) - Reported make and model: Enstrom F-28C - Registry model: [Enstrom F-28C](https://openairdocs.org/model/enstrom-f-28c) (registry code 3300407) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 445 - Engines: Lycoming HIO-360-F1AD 225 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Carl D. Hagglund - Airworthiness certificate: Special, Restricted (Special) ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 20,000 total, 20,000 in this make and model ## Weather - Conditions: Visual (VMC), Day - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 61 °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 19990406003309A](https://openairdocs.org/incident/19990406003309A), Apr 6, 1999: Enstrm F28C, Pendleton, OR, Substantial damage. (.19) On April 6, 1999, approximately 1730 pacific daylight time, a main rotor blade of an Enstrom F-28-C helicopter, N51770, impacted the aircraft's tail boom… 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.