# 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 5 of 8 · 372 cases

## Cases, newest first

- [NTSB DEN02LA013](https://openairdocs.org/ntsb/DEN02LA013.md): Bell 206B · Bryce, UT · Accident · Serious injuries · Limited investigation · Final report · Dec 1, 2001 · N911KH · Substantial damage
  > loss of engine power for reasons undetermined. Contributing factors were the low airspeed and altitude at which to perform an autorotation.
- [NTSB SEA02FA008](https://openairdocs.org/ntsb/SEA02FA008.md): Bell 206L · Anchorage, AK · Accident · 3 fatal · Field investigation · Final report · Oct 18, 2001 · N400EH · Substantial damage
  > The pilot's failure to maintain clearance from the surface of an open body of water while intentionally attempting to maintain a very low altitude while in cruise flight. Factors include falling snow, low ceilings, whiteout/greyout conditions, and flat/glassy…
- [NTSB LAX01FA306](https://openairdocs.org/ntsb/LAX01FA306.md): Bell 206B · Hilo, HI · Accident · Minor injuries · Field investigation · Final report · Sep 30, 2001 · N206KS · Destroyed
  > The failure of the mechanic to secure the No. 8 bearing thrust nut during maintenance work, which resulted in the total failure of the first stage turbine wheel shaft. Also causal was his misjudgment of his height during the flare resulting in a hard landing.…
- [NTSB CHI01LA327](https://openairdocs.org/ntsb/CHI01LA327.md): Bell 206B-III · Park Rapids, MN · Accident · Minor injuries · Limited investigation · Final report · Sep 27, 2001 · N56MC · Substantial damage
  > The pilot not maintaining altitude/clearance when he maneuvered above the glassy lake. A factor to the accident was the glassy lake condition.
- [NTSB LAX01LA305](https://openairdocs.org/ntsb/LAX01LA305.md): Hughes 369D · Carlsbad, CA · Accident · No injuries · Limited investigation · Final report · Sep 23, 2001 · N268ST · Substantial damage
  > A hard landing due to the dual student's failure to maintain main rotor speed, his improper landing flare, and the flight control interference by the flight instructor.
- [NTSB MIA01TA194](https://openairdocs.org/ntsb/MIA01TA194.md): Bell 206B-III · Jacksonville, FL · Accident · Minor injuries · Final report · Jul 25, 2001 · N313JP · Destroyed
  > the pilot's failure to recognize and correct for unanticipated right yaw/loss of tail rotor effectiveness (LTE) during an approach to hover at a low altitude, which resulted in a loss of control and the helicopter descending and colliding with a house and the…
- [NTSB LAX01IA262](https://openairdocs.org/ntsb/LAX01IA262.md): Mdhi 520N · Los Angeles, CA · Incident · No injuries · Incident investigation · Final report · Jul 25, 2001 · N953SD · Minor damage
  > the excitation of the first bending mode natural frequency of the aft tube assembly that is installed through the rotating NOTAR fan drive system. Contributing factors to the incident included the operator's maintenance practice of hand-sanding the pitch…
- [NTSB NYC01LA179](https://openairdocs.org/ntsb/NYC01LA179.md): McDonnell Douglas 369E · Niagara Falls, NY · Accident · No injuries · Limited investigation · Final report · Jul 19, 2001 · N577DB · Substantial damage
  > The right skid getting snagged on the helicopter-dolly resulting in dynamic rollover.
- [NTSB SEA01LA082](https://openairdocs.org/ntsb/SEA01LA082.md): Schweizer 269D · Nampa, ID · Accident · No injuries · Limited investigation · Final report · May 3, 2001 · N2061D · Substantial damage
  > the pilot's inadequate compensation for strong, gusty, shifting winds while hovering in ground effect. Factors include a sudden directional change and increase in velocity of the gusty wind conditions.
- [NTSB IAD01TA051](https://openairdocs.org/ntsb/IAD01TA051.md): Hughes 369D · Taylorsville, KY · Accident · Minor injuries · Final report · Apr 29, 2001 · N50AP · Substantial damage
  > the flight instructor's inadequate aircraft control during a practice autorotation which resulted in a hard landing.
- [NTSB CHI01LA119](https://openairdocs.org/ntsb/CHI01LA119.md): Hughes 369D · Du Quoin, IL · Accident · Minor injuries · Limited investigation · Final report · Apr 18, 2001 · N713HT · Destroyed
  > loss of engine power for undetermined reasons, the pilot operating the helicopter outside of the height-velocity curve, and the pilot's failure to maintain control of the helicopter during the emergency landing. Factors relating to the accident were the…
- [NTSB SEA01LA024](https://openairdocs.org/ntsb/SEA01LA024.md): Bell 206 B3 · Lake Kachess, WA · Accident · No injuries · Limited investigation · Final report · Nov 23, 2000 · N2062D · Substantial damage
  > The pilot's failure to comply with the flight manual regarding the use of an induction system deflector kit (snow baffles) while operating in snow, and the ingestion of foreign material/snow that resulted in an engine flameout while hovering. A snow baffle…
- [NTSB MIA01FA006](https://openairdocs.org/ntsb/MIA01FA006.md): Aerospatiale AS-355-F2 · Burlington, NC · Accident · 1 fatal · Field investigation · Final report · Oct 17, 2000 · N355DU · Destroyed
  > The mechanics failure to comply with manufacturers instructions for correction of a illuminated main rotor gearbox oil pressure warning light resulting in the helicopter being dispatched on a ferry flight with a failed main rotor gearbox oil pump, failure of…
- [NTSB LAX01FA006](https://openairdocs.org/ntsb/LAX01FA006.md): McDonnell Douglas 369E · Kernville, CA · Accident · Minor injuries · Field investigation · Final report · Oct 8, 2000 · N819CE · Substantial damage
  > The pilot's improper storage of personal items and his inadequate preflight inspection, which resulted in the unlatching of the left rear cabin door during flight and allowing a plastic garment bag to blow out and strike the tail rotor.
- [NTSB SEA00LA197](https://openairdocs.org/ntsb/SEA00LA197.md): Bell 206BII · Newhalem, WA · Accident · No injuries · Limited investigation · Final report · Aug 24, 2000 · N90307 · Substantial damage
  > Debonding between the elastomeric material and the center plate of the transmission isolation mount.
- [NTSB LAX00MA273](https://openairdocs.org/ntsb/LAX00MA273.md): Aerospatiale AS 355F1 · Kahului, Maui, HI · Accident · 7 fatal · Major investigation · Final report · Jul 21, 2000 · N510TG · Destroyed
  > The pilot's inadequate decision by which he continued visual flight rules flight into instrument meteorological conditions. Also causal was his failure to maintain terrain clearance resulting in a collision with mountainous terrain. A contributing factor was…
- [NTSB FTW00LA181](https://openairdocs.org/ntsb/FTW00LA181.md): Bell 206B · Deville, LA · Accident · Minor injuries · Limited investigation · Final report · Jun 19, 2000 · N2277T · Substantial damage
  > the pilot's failure to maintain clearance with the external load that was setting on the ground while hovering. A contributing factor was the pilot's diverted attention.
- [NTSB LAX00TA186](https://openairdocs.org/ntsb/LAX00TA186.md): McDonnell Douglas 500N · Los Angeles, CA · Accident · No injuries · Final report · May 8, 2000 · N955SD · Substantial damage
  > The combined failure of the operator management and the check pilot to ensure the landing area was suitable for the slide on landing. Factors were the high vegetation that entangled the skids, resulting in the abrupt stop and nose down movement of the…
- [NTSB DEN00FA082](https://openairdocs.org/ntsb/DEN00FA082.md): McDonnell Douglas 369E · Bloomfield, NM · Accident · 2 fatal · Field investigation · Final report · May 2, 2000 · N1606K · Destroyed
  > The pilot's intentional buzzing (low level flying), and his failure to maintain clearance with the static wire. A factor was his physical impairment by a contraindicated drug controlled substance.
- [NTSB CHI00LA121](https://openairdocs.org/ntsb/CHI00LA121.md): Hughes 500C · Salina, KS · Accident · No injuries · Limited investigation · Final report · Apr 24, 2000 · N9177F · Substantial damage
  > the loss of tail rotor effectiveness and the autorotation performed by the pilot. The unfavorable wind was a contributing factor.
- [NTSB LAX00LA156](https://openairdocs.org/ntsb/LAX00LA156.md): Bell 407 · Grand Canyon, AZ · Accident · No injuries · Limited investigation · Final report · Apr 16, 2000 · N175PA · Substantial damage
  > The failure and subsequent disintegration of the oil cooler fan forward hanger bearing.
- [NTSB FTW00FA091](https://openairdocs.org/ntsb/FTW00FA091.md): Eurocopter BO105S-CBS-5 · Dalhart, TX · Accident · 4 fatal · Field investigation · Final report · Mar 10, 2000 · N335T · Destroyed
  > The pilot's failure to maintain control of the helicopter as a result of his continued flight into known adverse weather conditions. Factors were the dark night light condition, fog, low ceiling, and the pilot's lack of total instrument flight time.
- [NTSB LAX00LA109](https://openairdocs.org/ntsb/LAX00LA109.md): Hughes 500C · Pohnpei (Pacific Ocean) · Accident · Minor injuries · Limited investigation · Final report · Feb 18, 2000 · N437DS · Destroyed
  > The pilot reported that he and the observer were planning to conduct tuna spotting operations. This was to be the first flight of the day. After takeoff, about 100 to 150 feet above sea level, the helicopter began an uncommanded right turn, followed by an…
- [NTSB IAD00LA015](https://openairdocs.org/ntsb/IAD00LA015.md): Bell 206A · Brutus, NY · Accident · No injuries · Limited investigation · Final report · Jan 5, 2000 · N206GR · Substantial damage
  > Was the pilot's failure to maintain directional control after encountering a loss of tail rotor effectiveness.
- [NTSB LAX00LA047](https://openairdocs.org/ntsb/LAX00LA047.md): Boeing 369E · Taft, CA · Accident · No injuries · Limited investigation · Final report · Nov 30, 1999 · N5238C · Substantial damage
  > The fatigue failure of a second stage compressor vane due to erosion, which resulted in a catastrophic engine failure. An inadequate inspection of the compressor section by company maintenance personnel during the last 300-hour inspection was also causal in…
- [NTSB SEA00FA021](https://openairdocs.org/ntsb/SEA00FA021.md): Bell 206L-3 · Seattle, WA · Accident · Minor injuries · Field investigation · Final report · Nov 17, 1999 · N206AC · 2 aircraft · Substantial damage
  > Adequate separation and lookout not maintained by the pilots of both aircraft.
- [NTSB CHI00FA020](https://openairdocs.org/ntsb/CHI00FA020.md): Bell 206B · Cottage Grove, MN · Accident · 2 fatal · Field investigation · Final report · Nov 1, 1999 · N565KS · Destroyed
  > Undetermined.
- [NTSB LAX00GA025](https://openairdocs.org/ntsb/LAX00GA025.md): McDonnell Douglas 500N · San Jose, CA · Accident · 2 fatal · Final report · Oct 25, 1999 · N904PD · Destroyed
  > The pilot's in-flight loss of control due to the failure and separation of the forward thruster control cable telescoping sleeve ball swivel fitting, which resulted in a stuck thruster and the entry into an uncontrollable yaw/spin. Also causal was the…
- [NTSB LAX00LA016](https://openairdocs.org/ntsb/LAX00LA016.md): Bell 206-B3 · Soda Springs, CA · Accident · Minor injuries · Limited investigation · Final report · Oct 18, 1999 · N2296N · Substantial damage
  > The failure of the pilot-in-command to maintain landing skid clearance during hover taxi, which resulted in a dynamic rollover.
- [NTSB LAX99LA292](https://openairdocs.org/ntsb/LAX99LA292.md): Hughes 369HS · Pohnpei (Pacific Ocean) · Accident · 2 fatal · Limited investigation · Final report · Sep 1, 1999 · N42054 · Destroyed
  > An in-flight collision with the water for undetermined reasons.
- [NTSB LAX99LA237](https://openairdocs.org/ntsb/LAX99LA237.md): Hiller UH-12ET · Williams, CA · Accident · No injuries · Limited investigation · Final report · Jun 30, 1999 · N7173F · Substantial damage
  > The pilot's inadequate preflight planning and verification that fuel was available for the intended flight. A factor was the fuel quantity false indication.
- [NTSB NYC99LA147](https://openairdocs.org/ntsb/NYC99LA147.md): Bell 206B-III · Tinicum, PA · Accident · Minor injuries · Limited investigation · Final report · Jun 17, 1999 · N94WF · Substantial damage
  > The pilot's failure to maintain a proper altitude above the water.
- [NTSB LAX99LA253](https://openairdocs.org/ntsb/LAX99LA253.md): Hughes 369HS · Pacific Ocean (Pacific Ocean) · Accident · Minor injuries · Limited investigation · Final report · Jun 7, 1999 · N4278M · Destroyed
  > The removal of the tail rotor blade abrasion strips by the use of an unapproved method by the maintenance personnel which resulted in the imbalance of the tail rotor blade assembly and subsequent separation of the 90-degree gear box; the pilot/mechanic's…
- [NTSB MIA99FA158](https://openairdocs.org/ntsb/MIA99FA158.md): Hughes 369E · Intercession, FL · Accident · 1 fatal · Field investigation · Final report · May 20, 1999 · N144CM · Substantial damage
  > The pilot's improper fuel management that resulted in fuel exhaustion and a total loss of engine power.
- [NTSB LAX99FA136](https://openairdocs.org/ntsb/LAX99FA136.md): Bell 206B · Grand Canyon, AZ · Accident · 1 fatal · Field investigation · Final report · Apr 1, 1999 · N992UC · Destroyed
  > The failure of the flight crew to properly preflight the helicopter and to detect and remove accumulated snow from the engine inlets and plenum chamber. Factors in the accident were the clouded plenum chamber inspection window and the failure of preceding…
- [NTSB MIA99LA111](https://openairdocs.org/ntsb/MIA99LA111.md): Fairchild Hiller FH-1100 · Zephyrhills, FL · Accident · No injuries · Limited investigation · Final report · Mar 24, 1999 · N4412C · Substantial damage
  > The student pilot's improper use of flight controls (cyclic and collective) during a takeoff to a hover. This resulted in the helicopter encountering dynamic rollover and rolling over on its right side.
- [NTSB LAX99LA116](https://openairdocs.org/ntsb/LAX99LA116.md): Bell 206B · Delhi, CA · Accident · Minor injuries · Limited investigation · Final report · Mar 10, 1999 · N901CA · Substantial damage
  > The pilot's failure to maintain clearance while landing in proximity to high vegetation, which resulted in the inadvertent contact of the spray boom to the trees.
- [NTSB SEA99FA037](https://openairdocs.org/ntsb/SEA99FA037.md): Hiller UH-12E · Yellow Pine, ID · Accident · No injuries · Field investigation · Final report · Feb 28, 1999 · N2239 · Substantial damage
  > Altitude deviation during aerial taxi for undetermined reasons.
- [NTSB FTW99LA076](https://openairdocs.org/ntsb/FTW99LA076.md): Bell 206-B3 · Sabine Pass, TX · Accident · Minor injuries · Limited investigation · Final report · Feb 6, 1999 · N907CA · Substantial damage
  > The pilot's inadvertent flight into instrument meteorological conditions and subsequent spatial disorientation. Factors were the dark night conditions, the fog, and the pilot's failure to obtain a weather briefing prior to the flight.
- [NTSB DEN99TA031](https://openairdocs.org/ntsb/DEN99TA031.md): Hughes 369D · Woodruff, UT · Accident · No injuries · Final report · Jan 4, 1999 · N5013P · Substantial damage
  > A partial loss of engine power due to erosion in the compressor assembly module. Factors were a missing rotating labyrinth seal, the installation of which had not been performed by unknown maintenance personnel.
- [NTSB CHI98TA354](https://openairdocs.org/ntsb/CHI98TA354.md): Bell 206B-3 · Hinkley, MN · Accident · No injuries · Final report · Sep 12, 1998 · N52BH · Substantial damage
  > Loss of engine power due to failure of the engine governor.
- [NTSB LAX98LA200](https://openairdocs.org/ntsb/LAX98LA200.md): Hughes 369HS · Pacific Ocean (Pacific Ocean) · Accident · 2 fatal · Limited investigation · Final report · Jun 16, 1998 · N95MS · Destroyed
  > The improper shimmying of the tail rotor driveshaft by maintenance personnel which induced fatigue in the tail rotor driveshaft coupling causing it to fail, which resulted in a loss of tail rotor control. A factor is the failure of the pilot to recognize the…
- [NTSB FTW98LA235](https://openairdocs.org/ntsb/FTW98LA235.md): Bell 206BIII · Hurst, TX · Accident · No injuries · Limited investigation · Final report · May 21, 1998 · N206TA · Substantial damage
  > The pilot's delayed recovery from a simulated autorotative landing.
- [NTSB LAX98TA123](https://openairdocs.org/ntsb/LAX98TA123.md): Bell 206B · Santa Clarita, CA · Accident · No injuries · Final report · Mar 20, 1998 · N3186L · Substantial damage
  > The failure of the pilot to maintain adequate clearance with the wires. Additional factors in this accident are the position of the sun at that time of the day, which made it difficult to see the wires, and the lack of markings or poles for that series of…
- [NTSB SEA98LA024](https://openairdocs.org/ntsb/SEA98LA024.md): Bell 206L · Idaho Falls, ID · Accident · No injuries · Limited investigation · Final report · Dec 16, 1997 · N206LT · Substantial damage
  > loss of engine power for undetermined reason(s). A factor relating to the accident included a dirt berm/ridge in the field where the pilot executed the forced landing.
- [NTSB FTW97FA352](https://openairdocs.org/ntsb/FTW97FA352.md): Bell 407 · Grand Isle S108 · Accident · Minor injuries · Field investigation · Final report · Sep 18, 1997 · N467PH · Substantial damage
  > The tail rotor blade strike(s) that severed the aft portion of the tailboom, subsequently rendering the pilot with no tail rotor control while in cruise flight. A factor was the lack of suitable terrain for the forced autorotative landing.
- [NTSB ANC97GA126](https://openairdocs.org/ntsb/ANC97GA126.md): Bell BH-206B · Dillingham, AK · Accident · 1 fatal · Final report · Aug 21, 1997 · N18FH · Destroyed
  > The pilot's intentional VFR flight into instrument meteorological conditions (IMC). Factors associated with the accident are the pilot's failure to activate the cabin heating system, the lack of an operable windshield defogger, the pilot's overconfidence in…
- [NTSB FTW97LA252](https://openairdocs.org/ntsb/FTW97LA252.md): Bell 206B · New Iberia, LA · Accident · Serious injuries · Limited investigation · Final report · Jul 3, 1997 · N49661 · Substantial damage
  > the pilot's improper in-flight planning/decision. A related factor was his failure to follow the company procedure of maintaining visual contact with the external long-line cable, while hovering with it attached.
- [NTSB ATL97LA086](https://openairdocs.org/ntsb/ATL97LA086.md): McDonnell Douglas MDHC-369E · Okahumpka, FL · Accident · Serious injuries · Limited investigation · Final report · Jun 13, 1997 · N765KV · No damage
  > The failure of the crewmember to use the necessary safety equipment, and his subsequent fall from an elevated platform. A factor was the crewmember's distraction with an animal.
- [NTSB SEA97LA072](https://openairdocs.org/ntsb/SEA97LA072.md): Hiller UH-12E · Glide, OR · Accident · Minor injuries · Limited investigation · Final report · Mar 14, 1997 · N545HA · Substantial damage
  > failure of the pilot to maintain clearance from a power transmission line. Factors relating to the accident included ambient light conditions, which made the power line hard to see.

Next page: https://openairdocs.org/ntsb.md?engine=03020&page=6

## 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&page=5

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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.