# NTSB SEA04LA181: Hughes 369D, N505ST, Cottage Grove, OR, September 4, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 3, 2004, 19:30 local (Sep 4, 2004, 02:30 UTC) - Place: Cottage Grove, OR - Coordinates: 43.721668, -123.105003 - Nearby events: https://openairdocs.org/map.md?lat=43.7217&lon=-123.1050&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 24, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 60057 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA04LA181 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/60057/pdf - Page: https://openairdocs.org/ntsb/SEA04LA181 ## Probable cause In-flight loss of engine power during cruise for undetermined reasons. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - reason for occurrence undetermined (cause) - Forced landing, descent - emergency - autorotation - Hard landing, emergency landing - terrain condition - ground (contributing factor) ## Analysis At 1,000 feet AGL the pilot said the engine had a sudden loss of power and the collective became very heavy. After the pilot initiated an autorotation, he looked down and observed a split in the rotor rpm and the N2 needle. The pilot then elected to proceed to a rock pit he observed and initiated an autorotation. At 60 knots and 30 feet AGL, and just as the pilot pulled back on the cyclic to slow down, the helicopter impacted the ground with its left skid. The helicopter subsequently rolled over on its left side, sustaining substantial damage as the main rotor blades severed the tail boom. A post accident examination of the helicopter failed to reveal any anomalies which would have prevented normal operations. ## Factual narrative On September 3, 2004, about 1930 Pacific daylight time, a Hughes 369D helicopter, N505ST, was substantially damaged after impacting terrain following a forced landing near Cottage Grove, Oregon. The certificated private pilot and his two passengers were not injured. Visual meteorological conditions prevailed for the personal flight, which was conducted in accordance with 14 CFR Part 91, and a flight plan was not filed. The helicopter departed the Hobby Field Airport (77S), Creswell, Oregon, at 1830. According to the Pilot/Operator Aircraft Accident Report (NTSB form 6120.1/2), the pilot reported that while flying at an altitude of 1,000 feet AGL, "...the engine had a sudden power loss and the collective became very heavy." The pilot further reported that after he put the collective full down and began an autorotation, he looked down and observed a "split" in the rotor rpm and the N2 needle. The pilot stated he was over a steep side slope (60%) with trees at the bottom, when he saw a rock pit and made a decision to attempt a landing there. The pilot said he checked the rotor speed again, which was still at the bottom of the green, and the collective was still heavy. The pilot reported that he continued the autorotation at 60 knots, and at 30 feet AGL he pulled back on the cyclic to slow down to about 30 knots, at which point the helicopter made contact with the ground. The pilot stated that after the helicopter impacted the ground the left side skid separated, the helicopter fell over on its left side skidding to a stop, and the main rotor blades severed the tail boom. Two Federal Aviation Administration (FAA) airworthiness inspectors visited the accident site to conduct a post accident examination of the helicopter. The inspectors reported that flight continuity to all flight controls had been established, and that the aircraft had approximately 200 pounds of fuel on board. The inspectors further reported the fuel and bleed air lines did not leak after the engine was motored, the fuel nozzle had a good spray pattern, and there was "good fire" to the igniter. The inspectors stated that all five main rotor blades had been accounted for. On September 28, 2004, a subsequent examination of the aircraft's engine was conducted by representatives of the FAA and Rolls-Royce Corporation. The N1 drive train rotated free and continuous by the N1 tachometer drive pad utilizing a one-quarter inch drive ratchet. The N2 drive train rotated free and continuous by the N2 tachometer drive pad utilizing a one-quarter inch drive ratchet. Both engine gearbox magnetic indicating plugs were found void of material, and the engine did not exhibit any visual external damage. All engine pneumatic and oil lines were found at least finger tight and no fractured lines were found. No evidence of pre-impact failed components was found during the examination, which would have led to the reported power loss. ## Aircraft - Registration: [N505ST](https://openairdocs.org/deregistered/N505ST-2005-07-28), registration cancelled 2005-07-28, S/N 1135D, built 1982 (OpenAirDocs) - Reported make and model: Hughes 369D - Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 1135D - Airframe hours: 2216 - Engines: Allison 250-C20 425 horsepower turbo shaft - Damage: Substantial damage - Flight: Business, Part 91 - Operator: Darren Kronberger - Registered owner: North West Lands Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 12, 2004, 5 hours before - Departed: 77S, Creswell, OR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; private; medical: class 3, valid medical--no waivers/lim.; last flight review February 23, 2003; seat: right; flight hours: 500 total, 300 in this make and model, 350 as pilot in command, 10 in the last 90 days, 5 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 54 °F - Altimeter: 30.12 inHg - Observed at: EUG, 350 nm away ## 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 20040903022349A](https://openairdocs.org/incident/20040903022349A), Sep 3, 2004: Hughes 369D, Cottage Grove, OR, Substantial damage. (-23) Pilot reported that he was apprx. 1000'AGL when he experienced a sudden loss of power and landed in a rock quarry area, the left skid caught the edge of… 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.