# NTSB SEA96LA096: Tilbert Baby Great Lakes, N94AT, Stevensville, MT, May 20, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 20, 1996, 09:45 local (15:45 UTC) - Place: Stevensville, MT - Coordinates: 46.500556, -114.099243 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.5006&lon=-114.0992&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 28, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 42368 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA96LA096 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42368/pdf - Page: https://openairdocs.org/ntsb/SEA96LA096 ## Probable cause the pilot's inadequate compensation for the wind conditions during the landing roll, which resulted in loss of directional control and an inadvertent ground swerve. Factors relating to the accident were: the adverse wind conditions (crosswind and gusts), rough terrain, and the pilot's lack of experience in the type of aircraft. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - weather condition - crosswind (contributing factor) - weather condition - gusts (contributing factor) - compensation for wind conditions - inadequate, pilot in command (cause) - directional control - not maintained, pilot in command (cause) - ground loop/swerve - inadvertent, pilot in command (cause) - lack of total experience in type of aircraft, pilot in command (contributing factor) - On ground/water encounter with terrain/water, landing - roll - terrain condition - rough/uneven (contributing factor) - Main gear collapsed, landing - roll - landing gear,main gear - overload ## Analysis The pilot reported that the accident flight was his first flight in the homebuilt airplane. The airplane was a sport bi-wing. During the landing rollout, gusts and crosswinds prevailed. The airplane veered off the runway, and the left gear collapsed. The pilot stated that he 'over-corrected' during the landing rollout, while he attempted to keep the airplane on the runway. No preimpact mechanical malfunction was reported by the pilot. In the 'Recommendation' section of NTSB Form 6120.1/2, the pilot stated: 'Become more familiar with aircraft flight and landing characteristics.' ## Factual narrative On May 20, 1996, about 0945 mountain daylight time, N94AT, a homebuilt Tilbert Baby Great Lakes airplane, operated by the owner/pilot, was substantially damaged during landing rollout in Stevensville, Montana. The commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight was conducted under 14 CFR 91. The pilot reported that the accident flight was his first flight in the homebuilt airplane. The airplane was a sport bi-wing. He stated: "After landing, on rollout, I got a wind gust from the left. The airplane weathervaned into the wind and got the left main gear off the pavement. I over-corrected to the right and when the left gear came back up on the pavement the airplane hopped a couple of times, folding the left gear and wrinkling the left wing tip." No preimpact mechanical malfunctions were reported by the pilot. In the "Recommendation" section of NTSB Form 6120.1/2 (attached), the pilot stated: "Become more familiar with aircraft flight and landing characteristics." ## Aircraft - Registration: [N94AT](https://openairdocs.org/deregistered/N94AT-2024-05-04), registration cancelled 2024-05-04, S/N 82963BGL, built 1994 (OpenAirDocs) - Reported make and model: Tilbert BABY GREAT LAKES (BABY GREAT) - Registry model: [Tibert Andrew E BABY GREAT LAKES](https://openairdocs.org/model/tibert-andrew-e-baby-great-lakes) (registry code 05624S6) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 82963BGL - Airframe hours: 41 - Engines: Lycoming O-235-C1 108 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Johnson, James F. - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, June 12, 1995, 26 hours before - Airport: 32S, Stevensville, runway 30, 3,800 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 49; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 1,487 total, 1 in this make and model, 1,487 as pilot in command, 9 in the last 90 days, 5 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 10 knots, gusting 20 - Lowest ceiling: 10,000 ft broken ## 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 19960520014389A](https://openairdocs.org/incident/19960520014389A), May 20, 1996: Amtrof BABYLAKES, Stevensville, MT, Substantial damage. First flight in homebuilt. Wind gust landing. Weathervaned. Over corrected hopped sideways folded gear. Wing damaged ## Other investigations on N94AT (1) 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 SEA01LA128](https://openairdocs.org/ntsb/SEA01LA128), Jul 7, 2001: Tibert Baby Lakes (N94AT), Stevensville, MT, substantial damage. Probable cause: The pilot's failure to maintain directional control of the tailwheel-equipped aircraft during the landing roll. Factors include the pilot's low total time in this make and model aircraft and his lack… 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.