# NTSB FTW01LA073: Hughes 369D, N8356F, Canadian, TX, March 2, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 2, 2001, 15:00 local (21:00 UTC) - Place: Canadian, TX - Coordinates: 35.909214, -100.379051 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.9092&lon=-100.3791&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report October 9, 2001 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 51851 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW01LA073 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51851/pdf - Page: https://openairdocs.org/ntsb/FTW01LA073 ## Probable cause the helicopter's encounter with loss of tail rotor effectiveness while hovering out-of-ground effect, and the pilot's failure to maintain control. A contributing factor was the soft terrain condition. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, hover - out of ground effect - loss of tail rotor effectiveness - encountered, pilot in command (cause) - directional control - not maintained, pilot in command (cause) - autorotation - performed, pilot in command - In flight collision with terrain/water, emergency descent/landing - terrain condition - soft (contributing factor) ## Analysis The pilot made an approach to a high hover due to the rough/uneven terrain. As the pilot was hovering the helicopter to a level area at 40 feet agl, the helicopter began to yaw to the right. The pilot stated that he hover taxied through his "rotor wash," and the helicopter encountered "loss of tail rotor effectiveness." The pilot increased collective in an attempt to takeoff, and the helicopter made "two quick revolutions." The pilot stated that he elected to land the helicopter instead of continuing with the takeoff due to power lines and rising terrain. The pilot initiated an autorotation, and the helicopter touched down on the soft ground while still rotating, collapsing the left landing skid. Subsequently, the tail rotor and main rotor blades struck the ground. The helicopter came to rest leaning toward its left side. ## Factual narrative On March 2, 2001, at 1500 central standard time, a Hughes 369D helicopter, N8356F, was substantially damaged following a loss of directional control while landing near Canadian, Texas. The helicopter was owned and operated by a private individual. The airline transport pilot and both passengers were not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 business flight. The flight had originated from a private helipad near Amarillo, Texas, approximately 1415. According to the pilot, he made an approach to a high hover due to the rough/uneven terrain. As he was hovering the helicopter at 40 feet agl to a level area, the helicopter began to yaw to the right. The pilot stated that he hover taxied through his "rotor wash," and the helicopter encountered "loss of tail rotor effectiveness." He increased collective in an attempt to takeoff, and the helicopter made "two quick revolutions." The pilot stated that he elected to land the helicopter instead of continuing with the takeoff due to power lines and rising terrain. The pilot initiated an autorotation, and the helicopter touched down on the soft ground while still rotating, collapsing the left landing skid. Subsequently, the tail rotor and main rotor blades struck the ground. The helicopter came to rest leaning toward its left side. Examination of the helicopter by the FAA inspector revealed that the tail rotor drive shaft was twisted and separated about 6 inches forward of the tail rotor gearbox. The tailboom was bent and one tail rotor blade was found separated. Control continuity was confirmed from the anti-torque pedals to the tail rotor pitch change links. All five main rotor blades were damaged. ## Aircraft - Registration: [N8356F](https://openairdocs.org/aircraft/N8356F), registered now, S/N 1260063D (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) - Category: Helicopter - Serial number: 1260063D - Airframe hours: 2600 - Engines: Allison 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Knut G. Mjolhus - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 3, 2000, 31.6 hours before - Departed: NONE, Amarillo, TX - Destination: NONE, Canadian, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; commercial, airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review September 3, 2000; seat: left; flight hours: 9,000 total, 700 in this make and model, 8,800 as pilot in command, 41 in the last 90 days, 20 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 55 °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 20010302004559A](https://openairdocs.org/incident/20010302004559A), Mar 2, 2001: Hughes 369D, Canadian, TX, Substantial damage. (-23) On March 2, 2001, at 1500 local time, a Hughes 369D helicopter N8356F was substantially damaged during a landing near Canadian, TX. The helicopter is… ## Other investigations on N8356F (2) 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 ERA09LA317](https://openairdocs.org/ntsb/ERA09LA317), Jun 2, 2009: Hughes 369D (N8356F), Greenville, VA, substantial damage. Probable cause: The inadequate design of the fourth-stage turbine wheel, resulting in the fatigue failure of one airfoil and a subsequent loss of engine power. - [NTSB SEA87LA074](https://openairdocs.org/ntsb/SEA87LA074), Apr 3, 1987: Hughes 369D (N8356F), Forks, WA, destroyed 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.