# NTSB GAA18CA583: Piper PA18, N9496D, Llano, TX, June 21, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 21, 2018, 10:00 local (15:00 UTC) - Place: Llano, TX - Coordinates: 30.784166, -98.661392 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.7842&lon=-98.6614&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 5, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 98611 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA583 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98611/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98611 - Page: https://openairdocs.org/ntsb/GAA18CA583 ## Probable cause The pilot's receiving instruction’s improper landing flare and his failure to maintain adequate airspeed and his exceedance of the airplane's critical angle of attack during landing, 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 · Student/instructed pilot (probable cause); cases with it: [Piper PA-18A 150, 18 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101837), [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-18A 150, 2 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=7101837), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-18A 150, 1 case](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=7101837), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/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-18A 150, 3 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=7101837), [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. - [Landing: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Piper PA-18A 150, 3 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=7101837), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Piper PA-18A 150, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=7101837), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot receiving instruction in the tailwheel-equipped airplane reported that, during landing, the airplane touched down abruptly. He added that he taxied to the edge of the runway and saw that the airplane was leaning left. The flight instructor reported that the pilot leveled off about 3 ft above the ground and allowed the airspeed to decrease. He added that he instructed the pilot to add power to "cushion the landing" and that the pilot attempted to do so, but the airplane continued to decelerate until it aerodynamically stalled and landed hard on the left main landing gear. The airplane sustained substantial damage to the fuselage. The instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Factual narrative The pilot receiving instruction in the tailwheel-equipped airplane reported that, during landing, the airplane touched downed abruptly. He added that he taxied to the edge of the runway and observed that the airplane was leaning to the left. The flight instructor reported that the pilot leveled off about 3 ft above the ground and allowed the airspeed to decrease. He added that he instructed the pilot to add power to "cushion the landing" and the pilot attempted to, but the airplane continued to decelerate until it aerodynamically stalled and landed hard on the left main landing gear. The airplane sustained substantial damage to the fuselage. The instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N9496D](https://openairdocs.org/aircraft/N9496D), registered now, S/N 18-6748, built 1958 (OpenAirDocs) - Reported make and model: Piper PA18 - Registry model: [Piper PA-18A 150](https://openairdocs.org/model/piper-pa-18a-150) (registry code 7101837) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-6748 - Year built: 1958 - Airframe hours: 5346.9 - Engines: Lycoming O-320-A2B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, December 29, 2017 - Departed: AQO, Llano, TX - Destination: AQO, Llano, TX - Airport: AQO, Llano Muni, runway 31, 3,209 × 150 ft, grass/turf - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 68; injuries: none; flight instructor, commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, waiver time limited special; seat: rear; restraint: 4-point; flight hours: 11,456 total, 1,252 in this make and model, 11,359 as pilot in command, 28 in the last 90 days, 5 in the last 30 days - Pilot; age 41; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; flight hours: 1,826 total, 1.2 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Temperature: 79 °F, dew point 72 °F - Altimeter: 30.01 inHg - Observed at: KAQO ## 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 20180621017059A](https://openairdocs.org/incident/20180621017059A), Jun 21, 2018: Piper PA-18A 150, Llano, TX, Substantial damage. During tail wheel transistion training at Llano, Texas the instructor [privacy data omitted] allowed [privacy data omitted] to land hard bending the forward… ## Other investigations on N9496D (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 DEN89LA214](https://openairdocs.org/ntsb/DEN89LA214), Sep 12, 1989: Piper PA-18A-150 (N9496D), Winston, NM, destroyed. Probable cause: DETERIORATED CARBURETOR FLOAT. FACTORS RELATED TO THE ACCIDENT WERE: HIGH DENSITY ALTITUDE AND THE TERRAIN CONDITIONS IN THE EMERGENCY LANDING AREA. ## Docket (4 files) The files NTSB released with the investigation on February 11, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98611. 5.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470307&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Flight Instructor's Statement (item 2, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470308&FileExtension=.PDF&FileName=Flight%20Instructor%27s%20Statement-Master.PDF - Record of Conversation - Pilot (item 3, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470309&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF - Accident Photos (item 4, .PDF, 2 photos, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470310&FileExtension=.PDF&FileName=Accident%20Photos-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.