# NTSB ANC09TA092: Aviat A-1B, N37HY, Gulkana, AK, September 3, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: September 3, 2009, 12:08 local (20:08 UTC) - Place: Gulkana, AK - Coordinates: 55.920391, -159.489883 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=55.9204&lon=-159.4899&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 12, 2010 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: U.S. Department of the Interior - NTSB case key (mKey): 74652 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC09TA092 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74652/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74652 - Page: https://openairdocs.org/ntsb/ANC09TA092 ## Probable cause The pilot's excessive use of brakes during an off-airport landing, resulting in the airplane nosing over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Aircraft capability: braking capability](https://openairdocs.org/ntsb-findings/01061050): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [Aviat A-1B, 2 cases](https://openairdocs.org/ntsb-findings/01061050/cases.md?model=2210406), [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/01061050/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Aviat A-1B, 4 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=2210406), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Aviat A-1B, 1 case](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=2210406), [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [Aviat A-1B, 19 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2210406), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot was on a federal public use wildlife surveillance flight under Title 14, Code of Federal Regulations Part 91. The pilot reported that while landing at an off-airport site he applied the brakes too hard and the airplane nosed over. He reported that there were no preaccident mechanical anomalies, and that the airplane sustained substantial damage to both wing lift struts, the vertical stabilizer, and the tops of the wings. ## Factual narrative On September 3, 2009, about 1208 Alaska daylight time, a tailwheel equipped, Aviat Husky A-1B airplane, N37HY, sustained substantial damage when it nosed over during landing at an off airport site, about 19 miles east of Gulkana, Alaska. The airplane was being operated by the U.S. Park Service, Department of Interior, as a visual flight rules (VFR) public use flight, under Title 14, CFR Part 91, when the accident occurred. The solo commercial pilot was not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on September 3, a spokesperson for the Park Service said the pilot was on a wildlife enforcement surveillance flight, and reported that the airplane nosed over during landing at the off airport site. He said there were no known mechanical anomalies with the airplane prior to the accident, and that the airplane sustained substantial damage to the wings, fuselage, and vertical stabilizer. In a written statement to the NTSB dated September 5, an investigator for the Department of the Interior, reported that the pilot said he had applied the brakes too hard during landing at the off-airport site, and the airplane nosed over. ## Aircraft - Registration: [N37HY](https://openairdocs.org/aircraft/N37HY), registered now, S/N 2037, built 1999 (OpenAirDocs) - Reported make and model: AVIAT AIRCRAFT INC A-1B - Registry model: [Aviat A-1B](https://openairdocs.org/model/aviat-a-1b) (registry code 2210406) (OpenAirDocs) - Registry engine: [Lycoming 0-360-A1D](https://openairdocs.org/engine/lycoming-0-360-a1d) (registry code 41504, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2037 - Airframe hours: 2311 - Engines: LYCOMING O-360-A1D 180 horsepower reciprocating - Damage: Substantial damage - Flight: Public aircraft - federal, Public use - Operator: United States Department Of Interior, doing business as U.S. Park Service - Registered owner: United States Department Of Interior - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 27, 2009 - Departed: GKN, Gulkana, AK - Destination: Gulkana, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 30, 2008; seat: front; flight hours: 1,700 total, 1,350 in this make and model, 1,600 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 6 knots, gusting 8 - Visibility: 10 statute miles - Lowest ceiling: 18,000 ft overcast - Temperature: 54 °F, dew point 39 °F - Altimeter: 29.77 inHg - Observed at: PAGK, 19 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 20090903048659A](https://openairdocs.org/incident/20090903048659A), Sep 3, 2009: Aviat Husky A-1B, Glennallen, AK, Substantial damage. Upon landing at an off airport site located 18 miles east of Glennallen, the aircraft flipped tail over nose. The airman stated he was correcting for a left… ## Docket (2 files) The files NTSB released with the investigation on July 7, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74652. 846 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 518 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332563&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - DOI Report (item 2, .PDF, 328 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40332564&FileExtension=.PDF&FileName=DOI%20Report-Redacted.PDF 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.