# NTSB FTW03LA102: Enstrom 280FX, N383MA, Ruston, LA, March 2, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 2, 2003, 12:00 local (18:00 UTC) - Place: Ruston, LA - Coordinates: 32.514446, -92.588333 - Nearby events: https://openairdocs.org/map.md?lat=32.5144&lon=-92.5883&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 2, 2004 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 56564 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW03LA102 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56564/pdf - Page: https://openairdocs.org/ntsb/FTW03LA102 ## Probable cause The separation of the upper tail cone as a result of a fractured bolt due to fatigue. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, standing - engine(s) operating - misc rotorcraft,tail cone - separation (cause) - miscellaneous,bolt/nut/fastener/clamp/spring - fractured (contributing factor) ## Analysis The 43-hour student helicopter pilot landed stated that he hovered the helicopter from the parking area to the taxiway for a west departure. After taxiing "at about a 2-3 foot skid height for about 100 yards, he settled the helicopter back down on the ground against a headwind, landing very, very gently." The pilot stated he started to "throttle down" the engine. At approximately 1/3 power, he heard a loud "splat," after which the helicopter "quivered." After shutting down the engine, the pilot exited the helicopter and noticed that the tail rotor was not turning. The 1986-model helicopter was reported to have accumulated a total of 1,609 hours since new. The investigation revealed that the tail cone separated and the associated bolt had fractured due to fatigue failure. ## Factual narrative On March 2, 2003, approximately 1200 central standard time, an Enstrom 280FX helicopter, N383MA, was substantially damaged when the tail boom separated while on the ground prior to takeoff at the Ruston Regional Airport (RNS) near Ruston, Louisiana. The helicopter was registered to and operated by the pilot. The private pilot, sole occupant, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 instructional solo flight. The cross-country flight was originating at the time of the accident and was destined for the Monroe Regional Airport, near Monroe, Louisiana. The 43-hour student helicopter pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that he hovered the helicopter from the parking area to the taxiway for a west departure. After taxiing "at about a 2-3 foot skid height for about 100 yards, he settled the helicopter back down on the ground against a headwind, landing very, very gently." The pilot stated he started to "throttle down" the engine. At approximately 1/3 power, he heard a loud "splat," after which the helicopter "quivered." After shutting down the engine, the pilot exited the helicopter and noticed that the tail rotor was not turning. According to a witness who was outside the fixed base operator, the pilot started taxiing to the middle of the ramp at approximately 2-3 feet above the ground. When the helicopter reached the middle of the ramp, the pilot started to set the helicopter on the ground. When the pilot got the helicopter on the ground, he started backing off the power. The witness then heard a loud noise. Another witness, standing approximately 1,500 feet away from the accident site, observed the helicopter taxiing from a hangar area toward the runway. The helicopter "appeared to be well controlled and handled by a qualified pilot." Before reaching the taxiway, the helicopter landed, and the witness heard a loud noise, "possibly a backfire." Both the main rotors and the tail rotor began slowing down. The tail rotor came to a stop while the main rotors continued to decelerate. The pilot noted that the tail was bent down and a bolt that holds the tail was broken in half. The pilot also noted that the tail rotor drive was bent and detached from the tail rotor, and the counter rotation cable control on the right side was broken. Examination of the helicopter tail boom by the FAA Inspector, who responded to the site, revealed that the upper tail cone bolt was fractured. Further examination of the tail boom revealed that the tail rotor drive shaft flex coupling was separated, the tail rotor drive shaft was bent, and the tail rotor control cable was separated. On November 28, 2003, an examination of the upper tail cone bolt at the National Transportation Safety Board Materials Laboratory revealed that the head of the bolt was rusted in most areas including inside the hexagon hole. The bolt itself was fractured at approximately the 5th thread from the shank and the mating section was missing. Examination of the upper tail cone bolt also revealed that the washer contained a 45 degree chamfer on one side to cover the large head radius with the shank. The washer contact face with the bolt head showed circumferential scoring marks. The bolt fracture surface was flat, on a plane perpendicular to the bolt axis, and contained arrest marks indicative of fatigue cracking over much of its area. The fatigue region initiated at the outer diameter surface of the bolt at a thread root and propagated across approximately 85 percent of the cross-sectional area prior to transitioning to tensile overstress. The 1986-model helicopter was reported to have accumulated a total of 1,609 hours since new. ## Aircraft - Registration: [N383MA](https://openairdocs.org/aircraft/N383MA), registered now, S/N 2048 (OpenAirDocs) - Reported make and model: Enstrom 280FX - Registry model: [Enstrom 280FX](https://openairdocs.org/model/enstrom-280fx) (registry code 3300506) (OpenAirDocs) - Registry engine: [Lycoming HI0-360 series](https://openairdocs.org/engine/lycoming-hi0-360-series) (registry code 41553, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2018 - Airframe hours: 1609 - Engines: Lycoming HIO-360-F1AD 225 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Herbert F. Vandenberg - Airworthiness certificate: Standard, Utility - Last inspection: Annual, September 1, 2002, 9 hours before - Departed: RSN, Ruston - Destination: MLU, Monroe, LA - Airport: RSN, Ruston Municipal Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private, student; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 123 total, 43 in this make and model, 53 as pilot in command, 5 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 340° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 3,400 ft broken - Temperature: 52 °F, dew point 39 °F - Altimeter: 30.15 inHg ## 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 20030302003459A](https://openairdocs.org/incident/20030302003459A), Mar 2, 2003: Enstrm 280FX, Ruston, LA, Minor damage. (-23) The pilot hovered to taxiway, landed and began to go through the aircraft checklist prior to take-off. He then heard a loud noise and felt the helicopter… ## Other investigations on N383MA (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 FTW02LA138](https://openairdocs.org/ntsb/FTW02LA138), Apr 29, 2002: Enstrom 280FX (N383MA), Alsatia, LA, substantial damage. Probable cause: The main rotor contact to the tail boom resulting from the pilot leaving the helicopter unattended while the rotors were engaged. - [NTSB NYC00LA174](https://openairdocs.org/ntsb/NYC00LA174), Jun 23, 2000: Enstrom 280 FX (N383MA), Springdale, OH, substantial damage. Probable cause: The pilot's inadequate preflight of the helicopter, and his subsequent failure to monitor his fuel supply, which resulted in a power loss due to fuel exhaustion, over unsuitable terrain. 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.