# NTSB FTW00LA254: Abernathy Streaker, N1LM, Sherman, TX, September 5, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 5, 2000, 11:30 local (16:30 UTC) - Place: Sherman, TX - Coordinates: 33.610576, -96.600715 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.6106&lon=-96.6007&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 25, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50209 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW00LA254 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50209/pdf - Page: https://openairdocs.org/ntsb/FTW00LA254 ## Probable cause The failure of the wing skin and the rear spar while performing aerobatics, which resulted in the restricted movement of the aileron. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - aerobatics - attempted, pilot in command - wing,skin - failure (cause) - wing,spar - buckled (cause) - Loss of control - in flight, maneuvering - flt control syst,aileron control - movement restricted (cause) ## Analysis During the first of three aerobatic contest flights, at 4,300 feet agl, the pilot began a 45 degree nose down dive into the 'aerobatic box'. After the 'second wing wag (used to signify the start of aerobatic performance),' the airplane experience a 'high rate' roll to the right. The pilot reported that the right aileron 'jammed.' The right wing's top skin failed and separated from the rear spar. The right wing rear spar buckled, and the leading edge of the aileron was 'jammed' under the trailing edge of the wing in the full up position. The pilot regained control of the airplane, and subsequently landed the airplane on the runway without further incident. ## Factual narrative On September 5, 2000, approximately 1130 central daylight time, an Abernathy Streaker aerobatic experimental biplane, N1LM, was substantially damaged while maneuvering near Sherman, Texas. The commercial pilot, sole occupant of the airplane, was not injured. The airplane was registered to a private individual and operated by the pilot. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulation Part 91 personal flight. The local flight originated from the Grayson County Airport, Sherman, Texas, at 1123. According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), and a telephone interview conducted by the NTSB investigator-in-charge, the pilot departed Grayson County Airport for the first of three aerobatic contest flights. At 4,300 feet agl, the pilot began a 45 degree nose down dive into the "aerobatic box". After the "second wing wag (used to signify the start of aerobatic performance)," the airplane experience a "high rate" roll to the right. The pilot reported that the right aileron "jammed," however, he eventually regained control of the airplane, and landed it on runway 17L without further incident. Examination of the airplane by the pilot revealed that the skin on the top of the right wing failed and separated from the rear spar. The rear spar was buckled and the aileron's leading edge was "jammed," in the full up position, under the wing's trailing edge. The airplane had accumulated 1,123 hours of total flight time at the time of the accident. ## Aircraft - Registration: [N1LM](https://openairdocs.org/aircraft/N1LM), registered now, S/N 1, built 1983 (OpenAirDocs) - Reported make and model: Abernathy STREAKER - Registry model: [Abernathy Robert L STREAKER](https://openairdocs.org/model/abernathy-robert-l-streaker) (registry code 05608M6) (OpenAirDocs) - Registry engine: [Lycoming AEIO-360 series](https://openairdocs.org/engine/lycoming-aeio-360-series) (registry code 41522, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 1 - Airframe hours: 1123 - Engines: Lycoming IO-360-AIE 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Alex Mirkovic - Registered owner: Brantley Coile - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, February 4, 2000, 70 hours before - Departed: F39 - Airport: F39, Sherman/Denison, runway 17L, 9,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 26; flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: center; flight hours: 3,400 total, 75 in this make and model, 2,850 as pilot in command, 120 in the last 90 days, 55 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 16 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 100 °F - Altimeter: 29.00 inHg 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.