# NTSB investigations: Amateur-built UNKNOWN ENG, MT

NTSB aviation accident and incident investigations since 1962: the probable cause, findings, aircraft, crew, weather and docket of each, linked to the FAA registry and the FAA’s own reports.

## Latest cases

- [NTSB WPR25LA271](https://openairdocs.org/ntsb/WPR25LA271.md): Naval Aircraft Factory N3N-3 · Red Lodge, MT · Accident · Minor injuries · Class 4 · Limited · Final report · Aug 31, 2025 · N45254 · Substantial damage
  > The pilot’s failure to maintain clearance from obstacles during an aborted landing. Contributing to the accident was the high density altitude weather condition.
- [NTSB WPR23LA354](https://openairdocs.org/ntsb/WPR23LA354.md): Kerr John Hatz Classic · Ennis, MT · Accident · No injuries · Class 4 · Limited · Final report · Apr 29, 2023 · N687HZ · Substantial damage
  > The pilot’s failure to maintain directional control during the landing roll which resulted in a ground-loop.
- [NTSB WPR21LA219](https://openairdocs.org/ntsb/WPR21LA219.md): Stoddard Hamilton Glasair II · Darby, MT · Accident · Serious injuries · Class 3 · Limited · Final report · May 29, 2021 · N8176J · Substantial damage
  > The pilot’s impact with terrain during a go-around following an attempted precautionary landing due to a low oil pressure indication. The reason for the low oil pressure indication could not be determined based on the available information.
- [NTSB GAA19CA475](https://openairdocs.org/ntsb/GAA19CA475.md): Avid Avid Mark IV · Thompson Falls, MT · Accident · Serious injuries · Data collection · Final report · Jul 30, 2019 · N4829W · Substantial damage
  > The student pilot's failure to go-around after a hard, bounced landing and the flight instructor's delayed remedial action, which resulted in a collision with trees at the departure end of the runway.
- [NTSB GAA18CA437](https://openairdocs.org/ntsb/GAA18CA437.md): Cessna 180 · Bozeman, MT · Accident · No injuries · Data collection · Final report · Jul 19, 2018 · N3224D · Substantial damage
  > The pilot's failure to maintain directional control during landing.
- [NTSB WPR16FA012](https://openairdocs.org/ntsb/WPR16FA012.md): Bucker Jungmeister BU 133 · Missoula, MT · Accident · 1 fatal · Field investigation · Final report · Oct 14, 2015 · N1940J · Destroyed
  > The pilot’s failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle of attack while executing a return to the runway after takeoff, which resulted in an aerodynamic stall/spin. Contributing to the accident was the pilot’s…
- [NTSB WPR11CA281](https://openairdocs.org/ntsb/WPR11CA281.md): Piper PA-36-285 · Havre, MT · Accident · No injuries · Data collection · Final report · Jun 23, 2011 · N57736 · Substantial damage
  > The pilot's failure to maintain directional control during takeoff.
- [NTSB SEA08CA010](https://openairdocs.org/ntsb/SEA08CA010.md): Welch RV-9 · Bigfork, MT · Accident · No injuries · Data collection · Final report · Oct 14, 2007 · N475TW · Substantial damage
  > Fuel starvation while on downwind for landing. The pilot's inadequate in-flight fuel management planning was a factor.
- [NTSB SEA06LA167](https://openairdocs.org/ntsb/SEA06LA167.md): Kinnson Lancair IV-P Turbine · Helena, MT · Accident · Minor injuries · Limited investigation · Final report · Aug 22, 2006 · N514PT · Substantial damage
  > The total loss of engine power as a result of turbine over temperature due to the pilot's failure to follow proper procedures for engine operation. A contributing factor was the lack of suitable terrain for the ensuing forced landing.
- [NTSB SEA06CA080](https://openairdocs.org/ntsb/SEA06CA080.md): Pitrolo GL-25 · Worden, MT · Accident · No injuries · Data collection · Final report · Apr 21, 2006 · N27EP · Substantial damage
  > The loss of engine power due to failure of both electronic ignition systems. A contributing factor was the lack of suitable terrain for the forced landing.
- [NTSB SEA06LA074](https://openairdocs.org/ntsb/SEA06LA074.md): Central Copters Lancair IV-P · Belgrade, MT · Accident · No injuries · Limited investigation · Final report · Apr 15, 2006 · N671 · Destroyed
  > The total loss of drive power to the aircraft's propeller while on a visual final approach, due to the decoupling of the quill shaft between the reduction gearbox and the engine power section. Factors include a dark night, no suitable terrain on which to…
- [NTSB SEA05LA189](https://openairdocs.org/ntsb/SEA05LA189.md): Ballhagen/Shyrock Q-2 · Kalispell, MT · Accident · No injuries · Limited investigation · Final report · Sep 2, 2005 · N12QJ · Substantial damage
  > The pilot/owner's improper setting of the engine's valve clearance, leading to the failure of the exhaust valves to fully close and a total loss of power while on a VFR downwind, and the pilot/owner's failure to maintain sufficient airspeed as he tried to…
- [NTSB SEA03LA007](https://openairdocs.org/ntsb/SEA03LA007.md): Riddell IV-P · Bozeman, MT · Accident · 1 fatal · Limited investigation · Final report · Nov 5, 2002 · N41RJ · Destroyed
  > The loss of power for undetermined reason(s) and the pilot's failure to maintain the aircraft's flying speed above the power off stall speed in the landing configuration.
- [NTSB SEA02LA130](https://openairdocs.org/ntsb/SEA02LA130.md): Thurmond Moni · Laurel, MT · Accident · No injuries · Limited investigation · Final report · Jul 12, 2002 · N9104S · Substantial damage
  > Undertorqued mounting bolts which resulted in fatigue to the wooden propeller blade and subsequent in flight separation of one of the blades while in cruise flight. An improper installation of the propeller assembly and soft terrain encountered during the…
- [NTSB SEA00LA144](https://openairdocs.org/ntsb/SEA00LA144.md): Eiriavion PIK 20E · Hamilton, MT · Accident · Serious injuries · Limited investigation · Final report · Jul 26, 2000 · N27RT · Destroyed
  > The pilot's entering an inadvertent stall condition during a high angle of bank turn (maneuvering), and the lack of adequate altitude in which to successfully recover before ground impact.
- [NTSB SEA99LA081](https://openairdocs.org/ntsb/SEA99LA081.md): D. Wayne Smith Wayncraft 14 · Libby, MT · Accident · 1 fatal · Limited investigation · Final report · Jun 6, 1999 · N58WS · Substantial damage
  > Collision with terrain for undetermined reasons.
- [NTSB SEA99LA061](https://openairdocs.org/ntsb/SEA99LA061.md): Eugene Hughes Lancair IV · Butte, MT · Accident · No injuries · Limited investigation · Final report · May 8, 1999 · N124GH · Substantial damage
  > The pilot's improper flare.
- [NTSB SEA98LA016](https://openairdocs.org/ntsb/SEA98LA016.md): Short Brothers SD3-60 · Billings, MT · Accident · No injuries · Limited investigation · Final report · Nov 25, 1997 · N691A · Substantial damage
  > The co-pilot's failure to maintain the proper descent rate on final approach, the pilot-in-command's delayed remedial action, and overload of the left main landing gear assembly. Factors contributing were snow, crosswind conditions and deteriorating…
- [NTSB SEA94LA244](https://openairdocs.org/ntsb/SEA94LA244.md): I.C.A. Brasov IS-28B2 · Bozeman, MT · Accident · No injuries · Limited investigation · Final report · Sep 10, 1994 · N28KG · Substantial damage
  > The student pilot's improper compensation for wind. The crosswind was a factor.
- [NTSB SEA91LA031](https://openairdocs.org/ntsb/SEA91LA031.md): Beech 3NM · Bozeman, MT · Accident · No injuries · Limited investigation · Final report · Dec 9, 1990 · N9159B · Substantial damage
  > The failure of the right engine master rod.
- [NTSB SEA90LA150](https://openairdocs.org/ntsb/SEA90LA150.md): Glasflugel H 301 Libelle · Thompson Falls, MT · Accident · No injuries · Limited investigation · Final report · Jul 29, 1990 · N4166A · Substantial damage
  > A disabled aircraft blocking the active runway.
- [NTSB DEN85FA131](https://openairdocs.org/ntsb/DEN85FA131.md): Consolidated-Vultee PBY-5A · Lewistown, MT · Accident · 1 fatal · Field investigation · Final report · May 9, 1985 · N84857 · Substantial damage
  > During taxi to takeoff the brakes failed. The plt attempted to groundloop the acft. The acft rolled down hill and collided with a gully. The plt was fatally injured. During preflight the co-plt inadvertently added hydraulic fluid in the alcohol tank. The…
- [NTSB DEN83LTI01](https://openairdocs.org/ntsb/DEN83LTI01.md): Scorpion 133 · Manhattan, MT · Accident · No injuries · Final report · Oct 3, 1982 · N133RW · Substantial damage
  > Battery failed because it had not been charged. No on board charging provision. Electric pump could not operate without electricity. No fuel to engine. During an autorotative landing, the tail rotor was damaged. With no tail rotor control, the helicopter slid…
- [NTSB SEA79FTI15](https://openairdocs.org/ntsb/SEA79FTI15.md): Scorpion II · Belgrade, MT · Accident · No injuries · Closed · May 21, 1979 · N133RW · Substantial damage
- [NTSB SEA67A0027](https://openairdocs.org/ntsb/SEA67A0027.md): Bell 47G3B1 · W.Yellowston, MT · Accident · 2 fatal · Closed · Sep 21, 1966 · N1169W · Destroyed

## The whole list in SQL

Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS:

```sql
SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url
FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1
WHERE c."eventStateOrRegion" = 'MT' AND c."eventCountry" = 'USA'
  AND c."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('99999'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=99999&state=MT

---
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.