# NTSB FTW98LA279: Schweizer 269C, N41TH, San Angelo, TX, May 20, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 20, 1998, 17:30 local (22:30 UTC) - Place: San Angelo, TX - Coordinates: 31.27964, -100.409996 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.2796&lon=-100.4100&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 20658 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA279 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20658/pdf - Page: https://openairdocs.org/ntsb/FTW98LA279 ## Probable cause The improper touchdown executed by the flight instructor, which resulted in the tail rotor impacting the ground. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - emergency procedure - simulated, pilot in command(cfi) - touchdown - improper, pilot in command(cfi) (cause) - rotor system,tail rotor blade - blade strike ## Analysis During a demonstration of an autorotation, the helicopter landed hard. The pilot reported that during the autorotation, after completing a flare, he added 'max' allowable power to initiate a power recovery and directional control was lost. Subsequently, the helicopter landed with a slight yaw. The passenger reported that during the autorotation the pilot stated that 'the spot we would land was visible basically right above the pedals.' The aircraft touched down 'firm,' approximately 90 degrees from the direction of travel. Examination of the helicopter revealed that the tailboom forward attachment fitting was fractured. Both tail rotor blades were attached to the hub and fork; however, one blade was found fractured and separated in the spar root area at the end of the hub spindle, and there was a dent in the leading edge near the tip. The tail rotor drive shaft was found twisted and disengaged from the upper pulley aft drive adapter. Examination of the tailboom forward attachment fitting, P/N:269A2323, and associated parts found that the fracture surface was 'consistent with an overstress failure.' There were 'no signs of preexisting cracks found.' ## Factual narrative On May 20, 1998, at 1730 central daylight time, a Schweizer 269C helicopter, N41TH, registered to Equi-Sky, Inc., and operated by Travland Helicopters, was substantially damaged during an autorotational landing near San Angelo, Texas. The flight instructor and his passenger were not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 CFR Part 91 personal flight. The flight originated from Mathis Field Airport, San Angelo, Texas, about 1700. The pilot reported that he was demonstrating an autorotation to the passenger. He further reported that during the "simulated autorotation" to an open field, and upon completing a flare, "I leveled the helicopter to what would approximate a hover and added max allowable power to initiate a power recovery with the intention of a go around." After applying power, directional control was lost and the helicopter landed hard with a slight yaw. The passenger reported that the pilot stated "he was going to demonstrate an autorotation so that I would understand how safe the helicopter is even without power." At the intended area for the demonstration, the pilot "retarded the throttle to idle." During the autorotation the pilot stated that "the spot we would land was visible basically right above the pedals." During the autorotational glide "directional control was stable." The nose of the aircraft raised "slightly" during the flare, which slowed the rate of descent "quickly." During the flare the helicopter turned clockwise. The aircraft "touched down approximately 90 degrees from the direction we were headed prior the flare." The landing seemed "firm" but not hard enough to be jarring. "Everything seemed to be under control." He did not remember the "engine accelerating at any time during the maneuver nor did he notice any unusual vibration." The pilot immediately shut down the engine and got out of the helicopter in a hurry. The passenger further reported that when he asked the pilot what happened, he remarked that "as he pulled collective and applied the pedals to compensate for the torque, that something seemed to give and the anti-torque pedal went to [the] floor." The passenger also reported that the ground was soft and partially plowed with furrows approximately 3 inches deep. Prior to the FAA arrival, the aircraft was moved to the Travland Helicopter's hangar located on Mathis Field Airport, San Angelo, Texas. A representative from the Schweizer Aircraft Corporation inspected the damage to the helicopter and removed the tailboom forward attachment fitting. Examination of the helicopter by the FAA inspector and the aircraft manufacturer revealed that the tailboom forward attachment fitting had separated at the attaching bolt hole. The vertical and horizontal stabilizers were damaged. The left forward diagonal tailboom support brace was bent. Both tail rotor blades were attached to the hub and fork; however, one blade had dirt on the leading edge and a small break in the skin on the trailing edge. The other blade was found fractured and separated in the spar root area at the end of the hub spindle, and there was a dent in the leading edge near the tip. The tail rotor drive shaft was found twisted and disengaged from the upper pulley aft drive adapter. The tailboom forward attachment fitting, P/N:269A2323, and associated parts were sent to the IMR Test Labs in Lansing, New York, by the aircraft manufacturer for examination. After this examination was completed, the NTSB investigator-in-charge had the parts examined at the NTSB Materials Laboratory in Washington, DC. Both examinations concluded that the fracture surface was "consistent with an overstress failure." There were "no signs of preexisting cracks found." ## Aircraft - Registration: [N41TH](https://openairdocs.org/aircraft/N41TH), registered now, S/N S1747, built 1997 (OpenAirDocs) - Reported make and model: Schweizer 269C - Registry model: [Schweizer 269C](https://openairdocs.org/model/schweizer-269c) (registry code 8059502) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1747 - Airframe hours: 178 - Engines: Lycoming HIO-360-D1A 190 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Lewis H. Travland, doing business as Travland Helicopters - Registered owner: Equi Sky, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 21, 1998, 10 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 13,034 total, 5 in this make and model, 12,957 as pilot in command, 49 in the last 90 days, 25 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 0° at 10 knots - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 97 °F, dew point 54 °F - Altimeter: 29.00 inHg - Observed at: SJT, 6 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 19980520014899A](https://openairdocs.org/incident/19980520014899A), May 20, 1998: Hughes 269C, San Angelo, TX, Substantial damage. During terminaiton of simulated autorotaiton tail boom support bracket failed. At attach bolt hole. Damaged rotors. (.4)during a demonstration of an… 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.