# Accident 19980725017549A: Enstrm F28F, Skwentna, AK, July 25, 1998 - Type: FAA accident report (Accident/Incident Data System), as reported - Date: July 25, 1998, 14:00 local time - Place: Skwentna, AK - Damage: Substantial damage - Phase of flight: Pwr On Vertical Ldng/Rtrcrft - Operating rules: Air taxi and commuter (Part 135) - Operator: EMVC - Location: 61.9299° N, 151.7295° W: From the FAA, an estimate near the named town, within about 3 miles - Nearby events: https://openairdocs.org/map.md?lat=61.9299&lon=-151.7295&mi=10 - Aircraft: N8622U, registered now (https://openairdocs.org/aircraft/N8622U) (OpenAirDocs) - Registry model: Enstrom F-28F (registry code 3300412, https://openairdocs.org/model/enstrom-f-28f) (OpenAirDocs) - Registry engine: Lycoming HIO-360 series (registry code 41524, https://openairdocs.org/engine/lycoming-hio-360-series) (OpenAirDocs) - Reported make and model: ENSTRM F28F - Reported engine: LYC HIO360* - People aboard: 2 - Fatal injuries: 0 - Pilot flight hours: 11,000 total, 1,200 in this make and model, 200 in the last 90 days - NTSB investigation: [NTSB ANC98LA109](https://openairdocs.org/ntsb/ANC98LA109) (OpenAirDocs) - FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/) - Page: https://openairdocs.org/incident/19980725017549A ## Narrative As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^. CRASHED EN ROUTE, ANCHORAGAE, AK. (-23) ON JULY 25, 1998, AT APPROXIMATELY 1400, ALASKA DAYLIGHT TIME, AN ENSTROM F28F, N8622U HELICOPTER LANDED HARD AFTER EXPERIENCING A LOSS OF POWER, WHILE COUNTING FISH FOR THE DEPARTMENT OF FISH AND GAME ON THE UPPER TALACHULITNA RIVER. THERE WERE NO INJURIES. THE COMMERCIAL CERTIFICATED PILOT WAS OPERATING THE FLIGHT IN VISUAL METEOROLOGICAL CONDITIONS. THE PILOT STATED, DURING A TELEPHONE CONVERSATION, THAT AFTER LANDING, HE AN EXHAUST GASKET COMPLETELY "COMPLETELY BLOW OUT." THE HEAT FROM THE BLOWN GASKET APPARENTLY HEATED A BOLT ON THE INTAKE MANIFOLD AND CAUSED IT TO BREAK AND CAUSE THE INTAKE MANIFOLD TO COME LOOSE. THE HELICOPTER WOULD NOT MAINTAIN OPERATING RPM AND THE PILOT WAS FORCED TO LAND THE HELICOPTER. HE ALSO STATED THAT THE LANDING HE MADE WAS A LITTLE DOWNWIND WITH LOW RPM, AS HE WAS UNABLE TO REGAIN FULL RPM DUE TO THE MECHANICAL FAILURE. THE HELICOPTER SUSTAINED SUBSTANTIL DAMAGE TO THE MAIN ROTOR BLADES AND THE TAIL ROTOR GEAR BOX DURING LANDING. (.4) THE CERTIFICATED COMMERCIAL HELICOPTER PILOT WAS CONDUCTING A SALMON SURVEY FOR THE STATE OF ALASKA, DEPARTMENT OF FISH & GAME. THIS OPERATION REQUIRED HIM TO HOVER THE HELICOPTER OVER THE STREAM WHILE THE PASSENGER, A WILDLIFE BIOLOGIST EMPLOYED BY THE STATE OF ALASKA, NOTED THE NUMBER OF FISH. THE PILOT STATED THAT WHILE IN A HOVER ABOVE THE STREAM, HE FELT A SLIGHT VIBRATION FOLLOWED BY A PARTIAL LOSS OF ENGINE POWER. HE SAID THAT WHILE HOVER TAXIING THE HELICOPTER TO A SUITABLE LANDING AREA, THE ENGINE CONTINUED TO LOSE POWER, AND HE WAS FORCED TO MAKE A DOWNWIND AUTOROTATION. HE SAID THAT AS THE HELICOPTER TOUCHED DOWN, THE MAIN ROTOR BLADES FLEXED DOWNWARD, AND STRUCK THE TAIL BOOM. THE HELICOPTER'S TAIL BOOM, AND TAIL ROTOR GEARBOX SUSTAINED SUBSTANTIAL DAMAGE. THE OPERATOR REPORTED THAT DURING A POSTACCIDENT INSPECTION OF THE ENGINE, A FRACTURED INTAKE MANIFOLD FLANGE WAS DISCOVERED ON THE NUMBER THREE CYLINDER ASSEMBLY. ## The NTSB's investigation of this event (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 ANC98LA109](https://openairdocs.org/ntsb/ANC98LA109), Jul 25, 1998: Enstrom F-28F (N8622U), Skwentna, AK, substantial damage. Probable cause: A loss of engine power due to a fractured number three cylinder intake manifold flange, and the pilot's inability to maintain the proper rate of descent during the autorotation flare. A contributing… ## Other reports on N8622U (1) Matched to the same aircraft by N-number and date. - [Accident 19831115057649A](https://openairdocs.org/incident/19831115057649A), Nov 15, 1983: Enstrm F28F (N8622U), Hillsboro, OR, Substantial damage. Helicopter engine lost power on climb after takeoff. Crash occurred during autorotation landing. From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record. --- 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.