# NTSB WPR22FA304: Aviat A-1A, N26HV, Yellow Pine, ID, August 15, 2022 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Field · Final report - Date: August 15, 2022, 06:30 local (12:30 UTC) - Place: Yellow Pine, ID · airport environment - Coordinates: 44.911722, -115.48552 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9117&lon=-115.4855&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Aviat Aircraft Inc., Lycoming Engines, Federal Aviation Administration - NTSB case key (mKey): 105737 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR22FA304 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105737/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105737 - Page: https://openairdocs.org/ntsb/WPR22FA304 ## Probable cause The pilot's failure to maintain adequate airspeed during an initial climb, which resulted in the exceedance of the critical angle of attack, subsequent aerodynamic stall, and impact with terrain. Contributing was the pilot’s decision to operate the airplane above its maximum gross weight. ## 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: [Aviat A-1A, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2210405), [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: [Aviat A-1A, 2 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=2210405), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Aircraft capability: maximum weight](https://openairdocs.org/ntsb-findings/01061035): Aircraft › Aircraft oper/perf/capability · Capability exceeded; cases with it: [Aviat A-1A, 1 case](https://openairdocs.org/ntsb-findings/01061035/cases.md?model=2210405), [All aircraft, 152 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Aviat A-1A, 4 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2210405), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Initial climb: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Aviat A-1A, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2210405), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis A video of the accident flight showed the airplane departed runway 35 and became airborne within the first half of the runway. As the airplane reached mid-field, it made a climbing right turn over the trees and disappeared from the camera view. The airplane impacted terrain shortly thereafter. The sound of the engine running can be heard throughout the video. Postaccident examination of the airplane revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation. A review of weight and balance information showed that, at the time of departure, the airplane was likely about 229 lbs over its maximum gross weight. Additionally, although the loading and seating positions could not be verified, an estimated calculation placed the airplane’s center of gravity (CG) outside of the manufacturer’s tested/approved CG envelope. Flight track data retrieved from a personal electronic device (PED), showed that the airplane’s speed decreased to 45 knots during the takeoff climb. The airplane's increased weight would have resulted in an increased stall speed. Given the increased airplane weight and the slow airspeed during the takeoff climb, it is likely that the pilot exceeded the airplane’s critical angle of attack, which resulted in an aerodynamic stall and subsequent impact with terrain. ## Factual narrative Federal Aviation Administration (FAA) publication H-8083-25A, Pilot's Handbook of Aeronautical Knowledge, stated that an aerodynamic stall results from a rapid decrease in lift caused by the separation of airflow from the wing's surface brought on by exceeding the critical angle of attack (AOA). AOA is defined as the acute angle between the chord line of the airfoil and the direction of the relative wind. An aerodynamic stall can occur when the airplane flies too slowly, or when higher wing loads are imposed due to maneuvers such as pull-ups or banked flight. On July 25, 2022, an Airglas Inc., LC18H cargo pod was installed, changing the airplane’s empty weight from 1286.5 to 1357.30. The addition of the cargo pod changed the airplane’s useful load from 603.5 lbs to 532.7 lbs. Weight and balance values were calculated for the accident flight using the airplane’s weight and balance records and the weights of the two occupants. The weight of the airplane at the time of departure from 3U2 was estimated to be about 229 lbs over the maximum gross weight assuming 40 gallons of fuel, reported or measured occupant weights, and baggage. The CG was calculated using the passenger and seat locations in the most favorable position and was found to be outside the manufacturer’s tested/approved CG envelope. According to the airplane’s flight manual, the stalling speeds for the airplane with 0° flaps, 0° bank, is 51 mph (~44 kts), with 0° flaps, 30° bank, is 55 mph (~47 kts). The stalling speeds for the airplane with 30° flaps, 0° bank, is 45 mph (~39 kts), with 30° flaps, 30° bank, is 48 mph (~41 kts). The airport manager for Johnson Creek Airport explained that it is common practice for aircraft departing from runway 35 to veer right of runway center line, about mid-field. The practice is done as an engine failure precautionary measure. On August 15, 2022, about 0630 mountain daylight time, an Aviat Aircraft Inc., A-1A, N26HV, was substantially damaged when it was involved in an accident near Yellow Pine, Idaho. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A witness camping at Johnson Creek Airport (3U2), Yellow Pine, Idaho, reported that on the morning of the accident flight, he observed the accident airplane taxiing to runway 35. Due to the cool weather, he returned to his tent. He recalled hearing the airplane’s engine rpm rise, like the pilot was conducting a runup. The witness stated that he then heard the airplane take off, which was followed shortly after by a sound similar to a "door slamming shut". Between 1030 to 1045, he departed runway 35 and flew to Yellow Pine, before returning to and flying over 3U2. While overflying the north end of the airport, he observed the accident airplane in the creek near the departure end of runway 35. A witness provided video of the accident flight that showed the accident airplane departing from runway 35. The airplanebecame airborne within the first half of the runway, then about mid-field, the airplane made a climbing right turn over the trees and out of sight. The sound of the engine was heard throughout the video consistent with an engine at high rpm. A review of data retrieved from an onboard PED showed that at 0636:45 the accident airplane departed from runway 35, climbed to a GPS altitude of 5,067 ft mean sea level (msl), with an airspeed of about 60 kts (GPS speed) and entered a climbing turn to the northeast. The data showed that the airplane continued on a northeast heading, reaching a GPS altitude of about 5,193 ft msl, with an airspeed of about 47 kts. At 0637:11, the accident airplane made a climbing left turn to the northwest, at a GPS altitude of about 5,203 ft msl, with an airspeed of about 45 kts. The data showed that the airplane continued on a northwest heading, the airspeed slowed to about 36 kts, and the airplane descended to about 5,153 ft msl until contact was lost, as seen in figure 1. Figure 1: Google Earth overly of the final portion of the accident flight. The Valley County Coroner’s Office, McCall, Idaho, performed an autopsy of the pilot. The cause of death was multiple blunt force injuries. Toxicology testing performed at the FAA Forensic Sciences Laboratory found no drugs of abuse. The pilot held a private pilot certificate that was issued about 9 months before the accident flight. At the time of the accident, he had accumulated about 170 total hours of flight experience, of which about 160 were in the accident airplane make and model. Examination of the accident site revealed that the airplane impacted terrain about 265 ft northeast of the departure end of runway 35. The airplane impacted terrain in a nose-low attitude and came to rest upright in a creek, on a heading of about 116° magnetic, at an elevation of 4,892 ft msl. No visible ground scars or damaged vegetation were observed in the area near the wreckage. All major structural components of the airplane were located at the accident site. Figure 2: View of the accident site diagram. Flight control continuity was established from the cockpit to all primary flight controls. Numerous separations were noted within the flight control system with signatures consistent with overload separation or due to the recovery process. Postaccident examination of the recovered airframe and engine did not reveal evidence of any mechanical anomalies that would have precluded normal operation. ## Aircraft - Registration: [N26HV](https://openairdocs.org/aircraft/N26HV), registered now, S/N 1410 (OpenAirDocs) - Reported make and model: AVIAT AIRCRAFT INC A-1A - Registry model: [Aviat A-1A](https://openairdocs.org/model/aviat-a-1a) (registry code 2210405) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1410 - Airframe hours: 1310.3 - Engines: LYCOMING O-360-A1P 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 20, 2021 - Airport: 3U2, Johnson Creek, runway 35, 3,400 × 150 ft, grass/turf - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: fatal; private; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; toxicology performed; flight hours: 173.4 total, 164.3 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 50 °F, dew point 37 °F - Altimeter: 30.16 inHg - Observed at: KMYL, 26 nm away - METAR: METAR KMYL 151251Z AUTO 21003KT 10SM CLR 10/03 A3016 RMK AO2 SLP168 T01000033 $= ## 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 20220815014599A](https://openairdocs.org/incident/20220815014599A), Aug 15, 2022: Aviat Aircraft Inc A-1A, Yellow Pine, ID, Destroyed, 2 fatal. At 0630 on the morning of August 15, 2022 the pilot and one passenger on a multi-day backcountry camping trip appears to have stalled and crashed shortly after… ## Other investigations on N26HV (2) 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 WPR13CA280](https://openairdocs.org/ntsb/WPR13CA280), Jun 21, 2013: Aviat A-1A (N26HV), McCall, ID, substantial damage. Probable cause: The pilot’s failure to maintain adequate airspeed while on approach for landing, which resulted in a loss of airplane control and a hard landing. - [NTSB DEN01LA038](https://openairdocs.org/ntsb/DEN01LA038), Jan 4, 2001: Aviat A-1A (N26HV), Eden, UT, substantial damage. Probable cause: the pilot's failure to maintain aircraft control during a landing attempt. A contributing factor was his failure to check the snow conditions in the field before the flight. ## Docket (22 files) The files NTSB released with the investigation on March 6, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105737. 158 MB in all. - Record of conversation airport manager (item 1, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16732133&FileExtension=pdf&FileName=Record%20of%20conversation%20-%20airport%20man-Rel.pdf - Record of phone conversation witness (item 2, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14785383&FileExtension=pdf&FileName=Record%20of%20phone%20conversation%20witness-Rel.pdf - Witness video (item 3, MOV, 63.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15363004&FileExtension=MOV&FileName=Witness%20video-Rel.MOV - Fuel receipt (item 4, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15349638&FileExtension=pdf&FileName=Fuel%20Receipt_Redacted-Rel.pdf - Pilot foreflight summary logbook (item 5, PDF, 1 page, 86 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15385035&FileExtension=pdf&FileName=ForeFlight%20Logbook%201-Rel.pdf - Airplane flight manual (item 6, PDF, 41 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15363014&FileExtension=pdf&FileName=Flight%20Manual%20A-1A-Rel.pdf - Cargo pod logbook entry (item 7, PDF, 1 page, 36.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15359232&FileExtension=pdf&FileName=Cargo%20pod%20logbook%20entry_Redacted-Rel.pdf - Weight and balance and performance summary (item 8, PDF, 4 pages, 186 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16732269&FileExtension=pdf&FileName=Weight%20and%20Balance%20and%20performance%20summary-Rel.pdf - Airplane weight and blance (item 9, PDF, 1 page, 34.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15349212&FileExtension=pdf&FileName=Weight%20and%20Blance_Redacted-Rel.pdf - Record of conversation valley county coroner (item 10, PDF, 1 page, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16733275&FileExtension=pdf&FileName=Record%20of%20conversation%20Valley%20County%20Coroner-Rel.pdf - Sheriff record of conversation for dog weight (item 11, PDF, 1 page, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16734031&FileExtension=pdf&FileName=Sheriff%20ROC%20for%20dog%20weight-Rel.pdf - WPR22FA304 accident site examination (item 12, PDF, 10 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16734075&FileExtension=pdf&FileName=WPR22FA304%20Accident%20Site%20Examination-Rel.pdf - WPR22FA304 airframe and engine exam (item 13, PDF, 13 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14786058&FileExtension=pdf&FileName=WPR22FA304%20Airframe%20and%20Engine%20Exam-Rel.pdf - Toxicological reports (item 14, PDF, 2 pages, 324 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14556738&FileExtension=pdf&FileName=Tox%20Report_Redacted-Rel.pdf - Autopsy memorandum (item 15, PDF, 1 page, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15347014&FileExtension=pdf&FileName=Autopsy%20Memo%20for%20Record-Rel.pdf - Materials laboratory factual report (item 16, PDF, 10 pages, 10 photos, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14894652&FileExtension=pdf&FileName=22-103%20-%20Materials%20Lab%20Factual%20Report%20(WPR22FA304)-Rel.pdf - Electronic devices - specialist's factual report_WPR22FA304 (item 17, PDF, 12 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15066489&FileExtension=pdf&FileName=Electronic%20Devices%20-%20Specialist%27s%20Factual%20Report_WPR22FA304-Rel.pdf - Attachment 1 to electronic devices - specialist's factual report_WPR22FA304 (item 18, CSV, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15067076&FileExtension=csv&FileName=Attachment%201%20to%20Electronic%20Devices%20-%20Specialist%27s%20Factual%20Report_WPR22FA304-Rel.csv - Photo array (item 19, PDF, 5 pages, 6.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15383798&FileExtension=pdf&FileName=Photo%20array-Rel.pdf - Statement of party representatives to NTSB investigation (item 20, PDF, 3 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15388657&FileExtension=pdf&FileName=Parties%20Forms_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 21, PDF, 1 page, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14785087&FileExtension=pdf&FileName=WPR22FA304%20Wreckage%20Release%20Form_Redacted-Rel.pdf - Evidence control forms (item 22, PDF, 8 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15395518&FileExtension=pdf&FileName=Evidence%20Control%20Forms_Redacted-Rel.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.