# NTSB investigations: Allison 250-C20 series

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.

Page 1 of 8 · 372 cases

## Latest cases

- [NTSB WPR26LA347](https://openairdocs.org/ntsb/WPR26LA347.md): Bell 206B-III · Creswell, NC · Accident · No injuries · Class 3 · Limited · Preliminary report · Sep 18, 2026 · N50141 · Substantial damage
  > On September 18, 2026, at 1018 eastern daylight time, a Bell 206B-III, N50141, was substantially damaged when it was involved in an accident near Creswell, North Carolina. The pilot was not injured. The helicopter was being operated as a Title 14 Code of…
- [NTSB WPR26LA199](https://openairdocs.org/ntsb/WPR26LA199.md): Bell 206-L4 · Cedar City, UT · Accident · Minor injuries · Class 4 · Limited · Final report · May 23, 2026 · N917SU · Substantial damage
  > The flight instructor's failure to maintain helicopter control while manipulating the engine governor reference rpm adjustment during hover operations, which resulted in a loss of control and impact with the ground.
- [NTSB CEN24LA377](https://openairdocs.org/ntsb/CEN24LA377.md): Mcdonnell Douglas Helicopter 369E · Manvel, TX · Accident · No injuries · Class 4 · Limited · Final report · Sep 30, 2024 · N8372F · Substantial damage
  > The pilot’s improper recovery from a practice autorotation which resulted in a hard landing. Contributing to the accident was the instructor’s inadequate supervision of the pilot receiving instruction.
- [NTSB WPR24LA319](https://openairdocs.org/ntsb/WPR24LA319.md): Bell 206L · Fern Prairie, WA · Accident · No injuries · Class 3 · Limited · Final report · Sep 26, 2024 · N9984K · Substantial damage
  > An aeroelastic interaction between the helicopter’s main rotor blades and nodal beam system, which resulted in oscillations that exceeded the design limits of the tailboom. Contributing to the accident was the failure of the main rotor blade manufacturer to…
- [NTSB ANC24FA089](https://openairdocs.org/ntsb/ANC24FA089.md): Bell 206B · King Salmon, AK · Accident · 1 fatal · Class 3 · Field · Final report · Sep 7, 2024 · N306FW · Substantial damage
  > The pilot’s decision to initiate the visual flight into instrument meteorological conditions, which resulted in his spatial disorientation, failure to maintain helicopter control and subsequent impact with water.
- [NTSB ERA24LA215](https://openairdocs.org/ntsb/ERA24LA215.md): Hughes 369 · Crestview, FL · Accident · No injuries · Class 4 · Limited · Final report · May 10, 2024 · N969VS · Substantial damage
  > The pilot’s improper flare, which resulted in a hard landing and the main rotor blades contacting the tail boom.
- [NTSB ANC24LA012](https://openairdocs.org/ntsb/ANC24LA012.md): Mcdonnell Douglas Helicopter 369E · Waialua, HI · Accident · No injuries · Class 4 · Limited · Final report · Jan 25, 2024 · N545PH · Substantial damage
  > The pilot's inability to maintain directional control after a skid got caught on a fence while he was maneuvering the helicopter for takeoff, which resulted in a dynamic roll-over.
- [NTSB CEN23LA404](https://openairdocs.org/ntsb/CEN23LA404.md): Mcdonnell Douglas Helicopter 369E · Arcola, TX · Accident · No injuries · Class 4 · Limited · Final report · Sep 7, 2023 · N8372F · Substantial damage
  > The instructor’s failure to re-apply engine power during a power recovery after a practice autorotation which resulted in a hard landing.
- [NTSB WPR23LA278](https://openairdocs.org/ntsb/WPR23LA278.md): Aerospatiale AS-355E Twin Star · Farmington, UT · Accident · No injuries · Class 3 · Limited · Final report · Jul 19, 2023 · N102UM · Substantial damage
  > The premature failure of one of the No. 2 engine compressor bleed valve, which resulted in a partial loss of power to that engine.
- [NTSB CEN23LA279](https://openairdocs.org/ntsb/CEN23LA279.md): Bell 206B · Chapman, KS · Accident · No injuries · Class 4 · Limited · Final report · Jul 5, 2023 · N67FA · Substantial damage
  > The pilot’s failure to maintain clearance from the power line during an agricultural application pass.
- [NTSB WPR23LA004](https://openairdocs.org/ntsb/WPR23LA004.md): Bell 206B · Fresno, CA · Accident · Serious injuries · Class 3 · Limited · Final report · Oct 1, 2022 · N284CA · Substantial damage
  > The disbond of a tail rotor drive shaft splined adapter, which resulted in a loss of tail rotor drive and a subsequent hard landing.
- [NTSB CEN22LA305](https://openairdocs.org/ntsb/CEN22LA305.md): Bell 206B · East Troy, WI · Accident · No injuries · Class 4 · Limited · Final report · Jul 1, 2022 · N882NY · Substantial damage
  > The pilot’s improper fuel management that resulted in fuel exhaustion and a loss of engine power.
- [NTSB WPR22LA236](https://openairdocs.org/ntsb/WPR22LA236.md): Bell 206B · Merced, CA · Accident · No injuries · Class 3 · Limited · Final report · Jun 24, 2022 · N915B · Substantial damage
  > The in-flight failure of the engine-to-transmission drive shaft due to a fatigue fracture of one of the KAflex flex frames caused by a loose bolt, which resulted in a total loss of power to the transmission and a subsequent hard landing.
- [NTSB ERA22LA206](https://openairdocs.org/ntsb/ERA22LA206.md): Bell 206 · Lake Apopka, FL · Accident · Minor injuries · Class 4 · Limited · Final report · Apr 26, 2022 · N206BX · Substantial damage
  > A collision with water following a loss of visual reference to the water surface due to sun glare.
- [NTSB CEN22LA146](https://openairdocs.org/ntsb/CEN22LA146.md): Hughes 369 · Adair, IA · Accident · Minor injuries · Class 3 · Limited · Final report · Mar 17, 2022 · N500MZ · Substantial damage
  > The mechanic’s failure to properly torque a fuel control unit B-nut, which resulted in a partial loss of engine power, an attempted autorotation, and an impact with terrain.
- [NTSB WPR22FA101](https://openairdocs.org/ntsb/WPR22FA101.md): Mcdonnell Douglas 500N · Newport Beach, CA · Accident · 1 fatal · Class 3 · Field · Final report · Feb 20, 2022 · N521HB · Substantial damage
  > The helicopter’s encounter with unanticipated right yaw during a low-altitude, low-airspeed, tight-radius orbit. Contributing to the accident was the pilot’s distraction during the orbit, which resulted in the loss of control, his fatigue due to his early…
- [NTSB ERA22LA117](https://openairdocs.org/ntsb/ERA22LA117.md): Hughes 369D · Bel Air, MD · Accident · No injuries · Class 3 · Limited · Final report · Feb 9, 2022 · N9159F · Substantial damage
  > A loss of engine power due to bearing failures in the turbine section resulting from a fatigue fracture of the oil supply line that fed oil to the Nos. 6 and 7 bearings. The oil line failure led to rapid deterioration of the bearings from oil starvation.…
- [NTSB CEN22FA086](https://openairdocs.org/ntsb/CEN22FA086.md): Bell 206B · Livingston, TX · Accident · 2 fatal · Class 3 · Field · Final report · Dec 30, 2021 · N8AU · Substantial damage
  > The pilot exceeding the yaw control capability of the helicopter for the flight conditions, resulting in a non-mechanical loss of tail rotor effectiveness.
- [NTSB CEN21LA356](https://openairdocs.org/ntsb/CEN21LA356.md): Bell 206 · Corydon, IN · Accident · Serious injuries · Class 4 · Limited · Final report · Aug 4, 2021 · N59552 · Substantial damage
  > The pilot’s failure to see and avoid power lines.
- [NTSB ERA21LA269](https://openairdocs.org/ntsb/ERA21LA269.md): Garlick Helicopters OH-58A+ · Alpine, AL · Accident · 1 fatal · Class 3 · Limited · Final report · Jun 25, 2021 · N372NS · Substantial damage
  > The pilot’s failure to maintain clearance from powerlines during a low-level aerial application flight, resulting in main rotor blade impact with a fiber-optic cable, a loss of control, and the helicopter’s subsequent impact with terrain.
- [NTSB ERA21LA262](https://openairdocs.org/ntsb/ERA21LA262.md): Mcdonnell Douglas Helicopter 369E · Swan Lake, NY · Accident · Serious injuries · Class 3 · Limited · Final report · Jun 18, 2021 · N371EE · Substantial damage
  > The pilot's failure to maintain adequate clearance from the power transmission tower structure during powerline maintenance work, which resulted in the helicopter's main rotor striking the lifeline support bracket for the tower catwalk and the subsequent loss…
- [NTSB ERA21FA130](https://openairdocs.org/ntsb/ERA21FA130.md): Bell 206 · St Thomas, CB · Accident · 4 fatal · Class 3 · Field · Final report · Feb 15, 2021 · N13AT · Destroyed
  > A total loss of engine power due to fatigue failure of two of the stage 3 compressor blades. Contributing to the failure of the compressor blades was the failure of maintenance personnel to inspect the compressor at the recommended interval for operation in…
- [NTSB ERA21LA126](https://openairdocs.org/ntsb/ERA21LA126.md): Bell 206 · Pahokee, FL · Accident · No injuries · Class 3 · Limited · Final report · Feb 4, 2021 · N820H · Substantial damage
  > A loss of main rotor rpm for reasons that could not be determined, which resulted in an autorotation and a subsequent hard landing and rollover.
- [NTSB ERA21LA028](https://openairdocs.org/ntsb/ERA21LA028.md): Bell 206 · Point Lookout, NY · Accident · Minor injuries · Class 3 · Limited · Final report · Oct 21, 2020 · N716VL · Substantial damage
  > The pilot’s decision to depart on a visual flight rules flight, and to continue that flight into forecasted and deteriorating instrument meteorological conditions (IMC) in a helicopter that was not equipped for flight in IMC, which resulted in the pilot’s…
- [NTSB CEN20LA273](https://openairdocs.org/ntsb/CEN20LA273.md): Aerospatiale AS355 · Rifle, CO · Accident · Serious injuries · Class 3 · Limited · Final report · Jul 11, 2020 · N708AC · Destroyed
  > A loss of tail rotor effectiveness, the pilot’s subsequent loss of helicopter control, and collision with terrain.
- [NTSB WPR20CA162](https://openairdocs.org/ntsb/WPR20CA162.md): Bell 206 · Elko, NV · Accident · No injuries · Class 4 · Data collection · Final report · May 30, 2020 · N401HP · Substantial damage
  > The pilot's failure to maintain helicopter control in gusting wind that resulted in a loss in altitude and subsequent collision with a fence.
- [NTSB ERA20LA160](https://openairdocs.org/ntsb/ERA20LA160.md): Hughes 369 · Pylesville, MD · Accident · No injuries · Class 3 · Limited · Final report · Apr 25, 2020 · N9159F · Substantial damage
  > The loss of engine power due to fuel starvation as a result of unporting of the fuel tank supply pickup while the helicopter was maneuvered to move a conductor wire. Contributing to the accident was the helicopter’s inappropriate configuration for the type of…
- [NTSB CEN20LA073](https://openairdocs.org/ntsb/CEN20LA073.md): Hiller UH 12E · Dinosaur, CO · Accident · No injuries · Class 3 · Limited · Final report · Feb 1, 2020 · N7173S · Substantial damage
  > Failure of a S4 compressor blade due to a fatigue crack that likely initiated at a corrosion pit. Contributing to the accident was maintenance personnel’s failure to detect the corrosion pits during maintenance.
- [NTSB WPR19LA135](https://openairdocs.org/ntsb/WPR19LA135.md): Bell 206 · Oxnard, CA · Accident · Serious injuries · Class 3 · Limited · Final report · May 4, 2019 · N49643 · Substantial damage
  > The pilot’s inability to maintain control of the helicopter while maneuvering at a low altitude due to reasons that could not be determined based on available evidence.
- [NTSB WPR19LA087](https://openairdocs.org/ntsb/WPR19LA087.md): MD Helicopter 369 · Kukuihaele, HI · Accident · Serious injuries · Class 3 · Limited · Final report · Feb 21, 2019 · N506PH · Substantial damage
  > The partial loss of engine power due to corrosion in the engine bleed valve due to wash solution intrusion. Contributing to the accident was the installation of a bushing manufactured to incorrect dimensions in the bleed valve, and the uneven terrain at the…
- [NTSB CEN19FA020](https://openairdocs.org/ntsb/CEN19FA020.md): Hughes 369 · McDougal, AR · Accident · 1 fatal · Class 2 · Field · Final report · Nov 2, 2018 · N5187S · Destroyed
  > The pilot's failure to maintain the helicopter's clearance from the powerline structure while hovering in gusty wind conditions, which resulted in an inadvertent collision with the structure and an uncontrolled descent into terrain.
- [NTSB ERA19FA035](https://openairdocs.org/ntsb/ERA19FA035.md): Aerospatiale AS 355F2 · Beekmantown, NY · Accident · 2 fatal · Field investigation · Final report · Oct 30, 2018 · N372CA · Destroyed
  > The pilot's failure to keep the helicopter clear of a utility pole while hovering with a tailwind, which resulted in a dynamic rollover into active power lines.
- [NTSB CEN18LA365](https://openairdocs.org/ntsb/CEN18LA365.md): MD Helicopters MD-369 · Orchard Lake, MI · Accident · Serious injuries · Limited investigation · Final report · Sep 3, 2018 · N1601Y · Substantial damage
  > The pilot's failure to maintain helicopter control and terrain clearance while in a hover after performing an evasive maneuver to avoid wildlife.
- [NTSB GAA18CA512](https://openairdocs.org/ntsb/GAA18CA512.md): Bell 206 · Battle Mountain, NV · Accident · No injuries · Class 4 · Data collection · Final report · Aug 18, 2018 · N8052G · Destroyed
  > The pilot's failure to maintain the proper altitude and airspeed while flying in a canyon in gusting wind conditions.
- [NTSB WPR18LA226](https://openairdocs.org/ntsb/WPR18LA226.md): Hughes 369 · Riverside, CA · Accident · Serious injuries · Class 3 · Limited · Final report · Aug 17, 2018 · N105JL · Substantial damage
  > The instructor’s delayed remedial action to an excessive descent rate during a simulated autorotation, which resulted in a hard landing.
- [NTSB ERA18LA183](https://openairdocs.org/ntsb/ERA18LA183.md): Bell 206 · Rio Grande, PR · Accident · 1 fatal · Limited investigation · Final report · Jun 30, 2018 · N10CV · Substantial damage
  > A total loss of engine power due to oil exhaustion, which resulted in an uncontrolled descent and hard landing.
- [NTSB WPR18LA164](https://openairdocs.org/ntsb/WPR18LA164.md): Bell 206 · Sanders, KY · Accident · Minor injuries · Class 3 · Limited · Final report · Jun 5, 2018 · N518Z · Substantial damage
  > A partial loss of engine power for undetermined reasons, and a loss of main rotor rpm during the subsequent autorotation, which resulted in a hard landing.
- [NTSB GAA18CA117](https://openairdocs.org/ntsb/GAA18CA117.md): Hughes Helicopters 369 · Wrightwood, CA · Accident · No injuries · Data collection · Final report · Feb 1, 2018 · N618SG · Substantial damage
  > The pilot’s high altitude, high gross weight landing with insufficient tail rotor thrust resulting in a loss of tail rotor effectiveness.
- [NTSB WPR18FA074](https://openairdocs.org/ntsb/WPR18FA074.md): Hughes 369D · Pomeroy, WA · Accident · 1 fatal · Field investigation · Final report · Jan 27, 2018 · N369TH · Substantial damage
  > A loss of control following the gunner's failure to ensure that the net maintained clearance from the tail rotor.
- [NTSB ERA18LA091](https://openairdocs.org/ntsb/ERA18LA091.md): Hughes 369 · San Juan, PR · Accident · Serious injuries · Limited investigation · Final report · Jan 11, 2018 · N571HH · No damage
  > The helicopter pilot's improper decision to use an open-end grapple, instead of an A-frame attachment, to lift and move a ladder with a lineman on it and the lineman's improper decision to be lifted on a ladder via an open-end grapple, which were contrary to…
- [NTSB WPR18LA029](https://openairdocs.org/ntsb/WPR18LA029.md): Bell 206 · Rolling Fork, MS · Accident · Minor injuries · Class 3 · Limited · Final report · Nov 7, 2017 · N93PH · Substantial damage
  > An uncommanded yaw and subsequent loss of main rotor rpm for reasons that could not be determined.
- [NTSB CEN17LA314](https://openairdocs.org/ntsb/CEN17LA314.md): Hughes 369D · Villa Grove, CO · Accident · Serious injuries · Limited investigation · Final report · Aug 10, 2017 · N58424 · Substantial damage
  > The pilot’s failure to maintain main rotor clearance from a power line tower during low-level maneuvering.
- [NTSB GAA17CA402](https://openairdocs.org/ntsb/GAA17CA402.md): Bell 206 · Uniontown, KY · Accident · No injuries · Data collection · Final report · Jun 30, 2017 · N60KH · Substantial damage
  > The pilot's failure to maintain adequate separation from power lines, which resulted in a loss of helicopter control.
- [NTSB GAA17CA369](https://openairdocs.org/ntsb/GAA17CA369.md): Bell 206B · Entiat, WA · Accident · No injuries · Data collection · Final report · Jun 26, 2017 · N183TC · Substantial damage
  > The pilot’s failure to secure a loose item inside the cockpit that interfered with antitorque pedal control and led to a loss of helicopter control due to a loss of tail rotor effectiveness.
- [NTSB ERA17LA209](https://openairdocs.org/ntsb/ERA17LA209.md): Hughes 369 · Dennis, WV · Accident · No injuries · Limited investigation · Final report · Jun 23, 2017 · N765KV · Substantial damage
  > The unporting of fuel due to the helicopter's nose-up attitude during long line operations, which resulted in fuel starvation and a total loss of engine power.
- [NTSB ERA17TA170](https://openairdocs.org/ntsb/ERA17TA170.md): Bell 206 · Orange Springs, FL · Accident · Serious injuries · Final report · May 2, 2017 · N911GE · Substantial damage
  > The pilot's failure to maintain adequate clearance between the helicopter's skid and the firefighting bucket and suspension cable, which resulted in the cable becoming entangled on the landing skid and a subsequent loss of helicopter control.
- [NTSB GAA17CA218](https://openairdocs.org/ntsb/GAA17CA218.md): Bell 206 · La Verne, CA · Accident · No injuries · Data collection · Final report · Apr 6, 2017 · N206SA · Substantial damage
  > The pilot’s early increased application of the collective during a simulated hovering autorotation, which resulted in a loss of rotor rpm and subsequent main rotor blade strike of the tailboom.
- [NTSB WPR17LA075](https://openairdocs.org/ntsb/WPR17LA075.md): Hughes 369A · (Pacific Ocean) · Accident · Serious injuries · Limited investigation · Final report · Feb 22, 2017 · N805LA · Substantial damage
  > The pilot's failure to detect the presence of water in the helicopter fuel system before the flight, which resulted in a total loss of engine power during cruise. Contributing to the accident was the pilot's delayed recognition of the power loss and late…
- [NTSB CEN17FA100](https://openairdocs.org/ntsb/CEN17FA100.md): Bell 206B · Galveston, TX · Accident · 1 fatal · Field investigation · Final report · Feb 7, 2017 · N978RH · Destroyed
  > The pilot's failure to recognize the flight had encountered instrument meteorological conditions at night, which resulted in an unrecognized descent and collision with water.
- [NTSB WPR16LA188](https://openairdocs.org/ntsb/WPR16LA188.md): Bell 206B · Rockport, WA · Accident · No injuries · Limited investigation · Final report · Sep 12, 2016 · N6181A · Substantial damage
  > The pilot's failure to maintain helicopter control while on the ground, which resulted in mast bumping.

Next page: https://openairdocs.org/ntsb.md?engine=03020&page=2

## 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."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03020'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=03020

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