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WPR21LA239 · Mooney M20J

20 Jun 2021 · West Glacier, MT, United States

Integrative Aerospace Mooney M20J · Accident: collision during takeoff/landing

From an unrecorded airport to Kalispell City Airport (S27)

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Event

NTSB case
WPR21LA239
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
Event fatalities
Unknown
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Mooney M20J

Aircraft type
Mooney M20
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N5765N
Onboard fatalities
Unknown
Route
From not recordedTo Kalispell City Airport (S27), Kalispell, MT
Aircraft age
About 37 years (built 1984)
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Takeoff
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Collision during takeoff/landing
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Personnel issues › Action/decision
  • Personnel issues › Task performance

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

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.

Probable cause

The pilot’s inadequate performance planning and decision to continue the takeoff which, resulted in a runway overrun and collision with terrain.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR21LA239
Event ID
20210623103320
Case number
WPR21LA239
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates, cause areas. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: b2d6207a68c146d705f73cc527271f403eddae5b2658a28312ea3c9b2186ec4a; retrieved 2026-09-16T14:12:15.386Z.