# NTSB CHI97LA251: Larsen T-BIRD II, N41873, Oshkosh, WI, August 3, 1997 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: August 3, 1997, 07:25 local (12:25 UTC) - Place: Oshkosh, WI - Coordinates: 44.059879, -88.540771 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.0599&lon=-88.5408&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report September 7, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 10665 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI97LA251 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10665/pdf - Page: https://openairdocs.org/ntsb/CHI97LA251 ## Probable cause the pilot's failure to maintain flying speed and loss of control resulting in a stall. Factors were the tree and the fence. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, climb - airspeed - not maintained, pilot in command - stall - encountered, pilot in command - aircraft control - not maintained, pilot in command - object - tree(s) - In flight collision with object, descent - uncontrolled - object - fence ## Analysis The pilot-in-command stated that approximately 40 feet above ground level after takeoff from the 1500 foot grass field, the airplane, 'Would not climb hardly enough to clear the first set of trees.' The pilot reported that he, 'Could not get the nose down to gain airspeed. Turned aileron left, plane went right headed towards antiques airplanes. Used only rudder, and it turned left but went into a full stall hitting trees...' The aircraft came to rest after impacting a tree line and a chain-link fence. Witnesses to the accident reported that the airplane's engine was operating and at full power at the time of the accident. Post accident investigation revealed no anomalies with the aircraft or engine. Control continuity was confirmed for both roll and pitch axis with no anomalies found. The pilot further stated, 'When we arrived at the field that morning someone was in the cabin with the door open. I believe he or someone tampered with the controls.' ## Factual narrative On August 3, 1997, at 0725 central daylight time, a Larsen T-Bird II, N41873, piloted by a private pilot sustained substantial damage when it collided with a tree line during initial climb from the ultralight strip (1,500 feet by 200 feet, dry/grass) at the Whittman Regional Airport, Oshkosh, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot received minor injuries and the one pilot-rated passenger sustained serious injuries. The flight was originating at the time of the accident and had the planned destination of Portage Municipal Airport, Portage, Wisconsin. According to the pilot-in-command's written statement, approximately 40 feet above ground level the airplane, "Would not climb hardly enough to clear the first set of trees." The pilot reported that he, "Could not get the nose down to gain airspeed. Turned aileron left, plane went right. Used only rudder, and it turned left but went into a full stall hitting trees." The aircraft came to rest after impacting a tree line and a chain-link fence. The pilot further stated, "When we arrived at the field that morning someone was in the cabin with the door open. I believe he or someone tampered with the controls." Witnesses to the accident reported that the airplane's engine was operational and was at full power at the time of the accident. Post accident investigation revealed no anomalies with the aircraft or engine. Control continuity was confirmed for both roll and pitch axis with no anomalies found. ## Aircraft - Registration: [N41873](https://openairdocs.org/deregistered/N41873-2013-09-19), registration cancelled 2013-09-19, S/N 3343, built 1992 (OpenAirDocs) - Reported make and model: Larsen T-BIRD II - Registry model: [Larsen Gary L T- BIRD II](https://openairdocs.org/model/larsen-gary-l-t-bird-ii) (registry code 05618GN) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 3343 - Engines: Rotax 582 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Gary Larsen - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, April 1, 1997 - Destination: C47, PORTAGE, WI - Airport: OSH, Wittman Regional Airport, runway 28, 1,500 × 200 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; private; airplane ratings: single-engine land; medical: class 1, expired; seat: right; flight hours: 121 total, 121 as pilot in command, 15 in the last 90 days, 6 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 63 °F - Altimeter: 30.00 inHg - Observed at: OSH ## 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 19970803020489A](https://openairdocs.org/incident/19970803020489A), Aug 3, 1997: Amtr TBIRD, Portage, WI, Substantial damage. Struck trees on cllimbout from ultralite strip. (-23) the pilot reported that there was droplets of water on the wings prior to his takeoff. He stated that the… 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.