# NTSB GAA16CA495: Piper PA 11, N4681M, Grand Isle, VT, September 19, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 19, 2016, 12:00 local (16:00 UTC) - Place: Grand Isle, VT - Coordinates: 44.705554, -73.245552 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.7056&lon=-73.2456&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 18, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 94048 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA495 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94048/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94048 - Page: https://openairdocs.org/ntsb/GAA16CA495 ## Probable cause The pilot's failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle-of-attack during a simulated engine failure and forced landing with a tailwind, which resulted in an aerodynamic stall. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-11, 11 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Piper PA-11, 2 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=7101102), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Piper PA-11, 1 case](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=7101102), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Awareness of condition; cases with it: [Piper PA-11, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=7101102), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-11, 4 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=7101102), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [Piper PA-11, 1 case](https://openairdocs.org/ntsb-events/600/sequence.md?model=7101102), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md) - [Landing: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Piper PA-11, 3 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=7101102), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Piper PA-11, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7101102), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-11, 11 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101102), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of a tailwheel-equipped airplane reported that about 450 feet above the ground, he reduced the power to idle to simulate an engine failure and forced landing. The pilot further reported that he "pushed the nose over" and made a "left tear drop turn" to land on the opposite direction of the takeoff direction. When the pilot had about 15 to 20 degrees remaining in the turn, and was about 15 to 20 feet above the ground, he reported that he increased "back stick pressure" and the airplane entered an aerodynamic stall. Subsequently, the left wing dropped and the airplane impacted terrain in a nose low left wing down attitude. The left wing and fuselage sustained substantial damage. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot reported in the National Transportation Safety Board Pilot/ Operator Aircraft Accident/ Incident Report that he misjudged the wind speed and did not realize he was completing the simulated training maneuver with a tailwind. The accident airport did not have an automated weather observing system or wind indicator. ## Factual narrative The pilot of a tailwheel-equipped airplane reported that about 450 feet above the ground, he reduced the power to idle to simulate an engine failure and forced landing. The pilot further reported that he "pushed the nose over" and made a "left tear drop turn" to land on the opposite direction of the takeoff direction. When the pilot had about 15 to 20 degrees remaining in the turn, and was about 15 to 20 feet above the ground, he reported that he increased "back stick pressure" and the airplane entered an aerodynamic stall. Subsequently, the left wing dropped and the airplane impacted terrain in a nose low left wing down attitude. The left wing and fuselage sustained substantial damage. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot reported in the National Transportation Safety Board Pilot/ Operator Aircraft Accident/ Incident Report that he misjudged the wind speed and did not realize he was completing the simulated training maneuver with a tailwind. The accident airport did not have an automated weather observing system or wind indicator. ## Aircraft - Registration: [N4681M](https://openairdocs.org/aircraft/N4681M), registered now, S/N 11-190, built 1947 (OpenAirDocs) - Reported make and model: PIPER PA 11 (NO SERIES) - Registry model: [Piper PA-11](https://openairdocs.org/model/piper-pa-11) (registry code 7101102) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 11-190 - Year built: 1947 - Airframe hours: 6600 - Engines: Continental C-35-8 85 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, February 6, 2016 - Departed: VT26, SOUTH HERO, VT - Destination: VT26, SOUTH HERO, VT - Airport: VT15, Savage Island, runway 02, 2,500 × 90 ft, grass/turf - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; military, airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review August 30, 2016; seat: front; flight hours: 8,346 total, 150 in this make and model, 8,036 as pilot in command, 76 in the last 90 days, 31 in the last 30 days, 0.6 in the last 24 hours - Pilot-rated passenger; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, unknown; seat: rear ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 66 °F - Altimeter: 30.01 inHg - Observed at: KPBG, 10 nm away ## Docket (2 files) The files NTSB released with the investigation on December 5, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94048. 674 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 581 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446221&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Photo (Courtesy of WCAX.com) (item 2, .PDF, 1 photo, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446222&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20WCAX.com)-Master.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.