# NTSB WPR21LA239: Mooney M20J, N5765N, West Glacier, MT, June 20, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: June 20, 2021, 15:00 local (21:00 UTC) - Place: West Glacier, MT - Coordinates: 48.48, -113.96 - Nearby events: https://openairdocs.org/map.md?lat=48.4800&lon=-113.9600&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 103320 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA239 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103320/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103320 - Page: https://openairdocs.org/ntsb/WPR21LA239 ## Probable cause The pilot’s inadequate performance planning and decision to continue the takeoff which, resulted in a runway overrun and collision with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Mooney M20J, 13 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=5870219), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Mooney M20J, 2 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=5870219), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Mooney M20J, 1 case](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=5870219), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [Planning/preparation: performance calculations](https://openairdocs.org/ntsb-findings/02061010): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mooney M20J, 1 case](https://openairdocs.org/ntsb-findings/02061010/cases.md?model=5870219), [All aircraft, 114 cases](https://openairdocs.org/ntsb-findings/02061010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Mooney M20J, 8 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=5870219), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that, he was departing to the south on a 2,500 ft long grass runway at a mountain airport with an estimated 5,000 ft mean sea level density altitude. The pilot calculated the airplane’s performance using the pilot’s operating handbook, which revealed a takeoff distance of 1,800 ft on grass. According to the pilot, during the takeoff run, the airplane lifted off the ground after traveling between 1,250 ft and 1,870 ft down the runway as the airplane reached 60 mph. However, the airplane touched back down to the runway surface near the end of the runway and impacted fallen timber before it came to rest. The airplane sustained substantial damage to the rudder and right wing. The pilot reported that there were no mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot stated that, before his takeoff run, he observed the windsock, which indicated winds from the east at 9 kts. However, wind data retrieved from a nearby station and sounding information indicated that winds may have been from the north at 5 kt, which would have resulted in a tailwind. ## Aircraft - Registration: [N5765N](https://openairdocs.org/deregistered/N5765N-2023-01-14), registration cancelled 2023-01-14, S/N 24-1482, built 1984 (OpenAirDocs) - Reported make and model: MOONEY M20J - Registry model: [Mooney M20J](https://openairdocs.org/model/mooney-m20j) (registry code 5870219) (OpenAirDocs) - Registry engine: [Lycoming AEIO-360 series](https://openairdocs.org/engine/lycoming-aeio-360-series) (registry code 41522, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-1482 - Year built: 1984 - Airframe hours: 1306.7 - Engines: Lycoming IO-360-A3B6D 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Integrative Aerospace Corp - Registered owner: Integrative Aerospace Corp - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 19, 2021, 42 hours before - Destination: S27, Kalispell, MT - Airport: 2MT1, Ryan Fld, runway 15/33, 2,500 × 65 ft, grass/turf - Equipment: Stall warning system, Auto-pilot, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review January 9, 2020; seat: left; restraint: 3-point; flight hours: 805 total, 409 in this make and model, 716 as pilot in command, 15 in the last 90 days, 9 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 7,500 ft overcast - Temperature: 70 °F, dew point 46 °F - Altimeter: 30.17 inHg - Observed at: KGPI, 16 nm away - METAR: KGPI 202055Z 35005KT 10SM OVC075 21/08 A3017 RMK AO2 SLP203 T02110083 51003 $ ## 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 20210620010309A](https://openairdocs.org/incident/20210620010309A), Jun 20, 2021: Mooney M20J, West Glacier, MT, Substantial damage. The aircraft proceeded down runway 15 and achieved what was perceived as flight. The aircraft didn?t get more than 20-25 feet off of the ground before it… ## Other investigations on N5765N (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 DFW06CA047](https://openairdocs.org/ntsb/DFW06CA047), Dec 30, 2005: Mooney M20J (N5765N), Yoakum, TX, substantial damage. Probable cause: The pilot's misjudged distance/speed which resulted in an overrun. ## Docket (3 files) The files NTSB released with the investigation on October 13, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103320. 4.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12464603&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Email correspondence with pilot (item 2, PDF, 6 pages, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12464122&FileExtension=pdf&FileName=Email%20correspondence%20with%20pilot_Redacted-Rel.pdf - Accident photographs (item 3, PDF, 2 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12464384&FileExtension=pdf&FileName=Accident%20Photographs-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.