# NTSB CHI08CA203: Enstrom F28F, N8626E, Amberg, WI, July 23, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 23, 2008, 10:30 local (15:30 UTC) - Place: Amberg, WI - Coordinates: 45.48389, -87.976943 - Nearby events: https://openairdocs.org/map.md?lat=45.4839&lon=-87.9769&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 28, 2008 - Report: Approved by Office Director - NTSB case key (mKey): 68736 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08CA203 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68736/pdf - Page: https://openairdocs.org/ntsb/CHI08CA203 ## Probable cause The unsuitable terrain encountered by the pilot during a forced landing following a loss of engine power due to a cylinder head separation. Contributing to the accident was the tree. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Enstrom F-28F, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=3300412), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) - [Runway/land/takeoff/taxi surface](https://openairdocs.org/ntsb-findings/03023000): Environmental issues › Physical environment · Not specified (probable cause); cases with it: [Enstrom F-28F, 1 case](https://openairdocs.org/ntsb-findings/03023000/cases.md?model=3300412), [All aircraft, 253 cases](https://openairdocs.org/ntsb-findings/03023000/cases.md) - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Enstrom F-28F, 2 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=3300412), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Enstrom F-28F, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=3300412), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Enstrom F-28F, 3 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3300412), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Enstrom F-28F, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3300412), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Enstrom F-28F, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3300412), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot stated that the helicopter had undergone an annual inspection at the helicopter manufacturer, and he was returning when he felt a "sudden" yaw to the left during cruise flight about 32 miles from the destination airport. The pilot then performed an "immediate" descent to a clearing, and about 60 feet above ground level and 30 miles per hour, the engine lost power. The helicopter landed on its skids and spun 180 degrees, impacting a tree with its tail rotor. The tail boom separated from the fuselage and a fire ensued consuming about 10 acres of land. The pilot exited the helicopter through the "partially jammed" passenger door because the pilot door was "jammed." The pilot received minor injuries. Examination of the engine revealed a cylinder head that was separated from its barrel. ## Factual narrative The pilot stated that the helicopter had undergone an annual inspection at the helicopter manufacturer and was retuning when he felt a "sudden" yaw to the left during cruise flight about 32 miles from the destination airport. The pilot then performed an "immediate" descent to a clearing and about 60 feet above ground level and 30 miles per hour, the engine quit. The helicopter landed on its skids and spun 180 degrees, impacting a tree with its tail rotor. The tail boom separated from the fuselage and a fire ensued consuming about 10 acres of land. The pilot exited the helicopter through the "partially jammed" passenger door because the pilot door was "jammed." The pilot received minor injuries. Examination of the engine revealed a cylinder head that was separated from its barrel. ## Aircraft - Registration: [N8626E](https://openairdocs.org/deregistered/N8626E-2023-04-04), registration cancelled 2023-04-04, S/N 744 (OpenAirDocs) - Reported make and model: Enstrom F28F - Registry model: [Enstrom F-28F](https://openairdocs.org/model/enstrom-f-28f) (registry code 3300412) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 744 - Airframe hours: 1120.5 - Engines: Lycoming HIO-360-F1A0 reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Business, Part 91 - Registered owner: Pilot - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 1, 2008 - Departed: MNM, MENOMINEE, MI - Destination: IMT, IRON MOUNTAIN/K, MI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; private; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 3; flight hours: 2,500 total, 1,500 in this make and model, 10 in the last 90 days ## Weather - Conditions: Visual (VMC), Day ## 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 20080723843349A](https://openairdocs.org/incident/20080723843349A), Jul 23, 2008: Enstrm F28F, Amberg, WI, Destroyed. (-23) On July 23, 2008 at approximately 1030 cdlt the pilot of this Enstrom helicopter experienced a transient yaw to the left in cruise flight approximately… 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.