# NTSB investigations: Lycoming T-53 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 2 · 79 cases

## Latest cases

- [NTSB WPR24LA299](https://openairdocs.org/ntsb/WPR24LA299.md): Williams Helicopter UH-1H · Colusa, CA · Accident · Serious injuries · Class 4 · Limited · Final report · Aug 30, 2024 · N710WD · Substantial damage
  > The pilot’s failure to set collective friction which resulted in collective bounce and subsequent loss of control.
- [NTSB WPR24LA030](https://openairdocs.org/ntsb/WPR24LA030.md): Arrow Falcon Exporters UH-1H · Firebaugh, CA · Accident · No injuries · Class 3 · Limited · Final report · Nov 4, 2023 · N3053Q · Substantial damage
  > An on-ground fuel fire for reasons that could not be determined due to extensive thermal damage.
- [NTSB WPR23LA118](https://openairdocs.org/ntsb/WPR23LA118.md): Bell UH-1B · Orland, CA · Accident · No injuries · Class 4 · Limited · Final report · Mar 2, 2023 · N234SJ · Substantial damage
  > The pilot’s inadequate fuel planning, which resulted in fuel exhaustion and a loss of engine power.
- [NTSB WPR23LA097](https://openairdocs.org/ntsb/WPR23LA097.md): Kaman Aerospace K-1200 · Sweet Home, OR · Accident · No injuries · Class 3 · Limited · Final report · Jan 24, 2023 · N202WM · Substantial damage
  > Improper installation of the hardware retaining the adjustment screw in the N2 topping governor lever and roller assembly, which resulted in a partial loss of engine power.
- [NTSB WPR22LA339](https://openairdocs.org/ntsb/WPR22LA339.md): Bell 205A-1 · Cougar, WA · Accident · Minor injuries · Class 3 · Limited · Final report · Sep 7, 2022 · N66HJ · Substantial damage
  > The helicopter’s encounter with downdrafts during a low-altitude hovering maneuver while dipping for water.
- [NTSB ANC22FA047](https://openairdocs.org/ntsb/ANC22FA047.md): Bell UH1B · Clear, AK · Accident · 1 fatal · Class 3 · Field · Final report · Jun 27, 2022 · N9970F · Destroyed
  > A loss of control for reasons that could not be determined based on the available information.
- [NTSB WPR22LA084](https://openairdocs.org/ntsb/WPR22LA084.md): Bell UH-1E · Gustine, CA · Accident · No injuries · Class 3 · Limited · Final report · Jan 23, 2022 · N333XL · Substantial damage
  > Failure of the 90° gearbox due to the lack of lubricating oil, which resulted in a loss of rotational drive to the tail rotor and a subsequent loss of control of the helicopter.
- [NTSB WPR20LA211](https://openairdocs.org/ntsb/WPR20LA211.md): Bell UH1H · Payson, AZ · Accident · 1 fatal · Class 3 · Limited · Final report · Jul 7, 2020 · N623PB · Destroyed
  > A flight control malfunction due to either a hydraulic hardover or a flight control stiffness event, which resulted in a loss of control.
- [NTSB ERA20FA027](https://openairdocs.org/ntsb/ERA20FA027.md): Grumman OV-1 · Stuart, FL · Accident · 1 fatal · Class 3 · Field · Final report · Nov 1, 2019 · N10VD · Destroyed
  > The pilot’s improper recovery from a low-altitude aerobatic maneuver, which resulted in descent into terrain.
- [NTSB GAA19CA345](https://openairdocs.org/ntsb/GAA19CA345.md): S M & T UH · Northway, AK · Accident · Serious injuries · Data collection · Final report · Jun 10, 2019 · N64771 · Substantial damage
  > The pilot's failure to maintain a proper descent rate during landing, which resulted in impact with terrain.
- [NTSB GAA17CA355](https://openairdocs.org/ntsb/GAA17CA355.md): Bell UH1B · Williams, CA · Accident · No injuries · Data collection · Final report · Jun 21, 2017 · N6180A · Substantial damage
  > The pilot’s failure to maintain clearance from transmission wires while maneuvering at a low altitude during an agricultural application flight.
- [NTSB WPR16LA104](https://openairdocs.org/ntsb/WPR16LA104.md): Bell UH 1B · Maxwell, CA · Accident · No injuries · Limited investigation · Final report · May 7, 2016 · N486SA · Substantial damage
  > A reduction in available engine power during takeoff due to a stuck hot air valve, which resulted in low rotor rpm and a forced landing. Contributing to the accident was the lack of dry film lubricant and the presence of corrosion on the hot air valve…
- [NTSB WPR15LA219](https://openairdocs.org/ntsb/WPR15LA219.md): Garlick UH1H · Walla Walla, WA · Accident · Minor injuries · Limited investigation · Final report · Jul 21, 2015 · N121PT · Destroyed
  > The helicopter’s reduction in aerodynamic lift while operating in variable wind conditions for reasons that could not be determined because postaccident examination did not reveal any evidence of preimpact mechanical malfunctions or failures that would have…
- [NTSB WPR14LA206](https://openairdocs.org/ntsb/WPR14LA206.md): Williams Helicopter UH 1H · Waitsburg, WA · Accident · Minor injuries · Limited investigation · Final report · May 23, 2014 · N260TA · Substantial damage
  > An extreme vibration immediately after entering forward flight for reasons that could not be determined because postaccident examination of the helicopter did not reveal any anomalies that would have precluded normal operation. Contributing to the accident…
- [NTSB WPR11LA423](https://openairdocs.org/ntsb/WPR11LA423.md): Arrow Falcon Exporters UH-1H · Stockton, CA · Accident · Minor injuries · Limited investigation · Final report · Sep 2, 2011 · N205PJ · Substantial damage
  > A total loss of engine power due to the separation of a tooth from the starter-generator drive gear, which resulted in failure of the engine oil pump and subsequent oil starvation.
- [NTSB WPR10FA295](https://openairdocs.org/ntsb/WPR10FA295.md): Kaman Aerospace K-1200 · Donnelly, ID · Accident · 1 fatal · Field investigation · Final report · Jun 16, 2010 · N134WC · Substantial damage
  > The collision of two counter-rotating main rotor blades for undetermined reasons, which resulted in a loss of control.
- [NTSB CEN09LA565](https://openairdocs.org/ntsb/CEN09LA565.md): Bell UH-1B · Arvilla, ND · Accident · Serious injuries · Limited investigation · Final report · Sep 6, 2009 · N204JB · Substantial damage
  > The aircraft owner/mechanic/pilot's installation of an improper tail boom assembly and the resulting fatigue failure of the tail boom's attach fittings.
- [NTSB WPR09LA241](https://openairdocs.org/ntsb/WPR09LA241.md): Rotorcraft Development UH-1B · Richvale, CA · Accident · Serious injuries · Limited investigation · Final report · May 13, 2009 · N843M · Substantial damage
  > The pilot's failure to maintain control of the helicopter during takeoff for undetermined reasons.
- [NTSB LAX07TA227](https://openairdocs.org/ntsb/LAX07TA227.md): Bell 205 A1++ · Happy Camp, CA · Accident · 1 fatal · Final report · Jul 23, 2007 · N205BR · Destroyed
  > the pilot's failure to maintain clearance with the trees during a long-line operation. Contributing factors were the Forest Service's inadequate communication between crews, failure to properly assess the safety of the intended drop zone, reduced visibility…
- [NTSB SEA07LA154](https://openairdocs.org/ntsb/SEA07LA154.md): Bell UH-1B · Biggs, CA · Accident · No injuries · Limited investigation · Final report · Jun 12, 2007 · N2087S · Substantial damage
  > Loss of control during hover for undetermined reasons.
- [NTSB SEA06LA162](https://openairdocs.org/ntsb/SEA06LA162.md): Kaman HH-43F · Metaline Falls, WA · Accident · 1 fatal · Limited investigation · Final report · Aug 18, 2006 · N559D · Destroyed
  > The failure of the left-hand cross-shaft input internal spline while the helicopter was in a hover, which resulted in the loss of gear box timing, in-flight blade contact and separation, and the subsequent loss of control and impact with a log deck.
- [NTSB LAX06LA134](https://openairdocs.org/ntsb/LAX06LA134.md): Bell UH-1H · Yuba City, CA · Accident · No injuries · Limited investigation · Final report · Apr 1, 2006 · N710WD · Substantial damage
  > The pilot's in-flight loss of control of the helicopter for undetermined reasons. A factor was the trees.
- [NTSB SEA05CA086](https://openairdocs.org/ntsb/SEA05CA086.md): Williams Helicopter UH-1B · Uniontown, WA · Accident · No injuries · Data collection · Final report · Apr 25, 2005 · N334WN · Substantial damage
  > The pilot's failure to maintain clearance from an object while maneuvering, which resulted in the main rotor blades striking a power pole. The power pole was a factor in the accident.
- [NTSB SEA05WA091](https://openairdocs.org/ntsb/SEA05WA091.md): Bell UH-1F · Banda Ache, Indonesia · Accident · No injuries · Foreign investigation · Mar 29, 2005 · N4040P · Substantial damage
- [NTSB FTW04WA173](https://openairdocs.org/ntsb/FTW04WA173.md): Bell UH-1B · Las Bocas, Mexico · Accident · No injuries · Foreign investigation · Jun 12, 2004 · N64CC · Substantial damage
- [NTSB SEA04LA043](https://openairdocs.org/ntsb/SEA04LA043.md): Garlick UH-1H · Liberty, WA · Accident · Serious injuries · Limited investigation · Final report · Feb 23, 2004 · N6257P · Substantial damage
  > The failure of the tail rotor slider lugs due to fatigue while the helicopter was maneuvering.
- [NTSB LAX04LA015](https://openairdocs.org/ntsb/LAX04LA015.md): Bell UH-1B · Durham, CA · Accident · No injuries · Limited investigation · Final report · Oct 16, 2003 · N234SJ · Substantial damage
  > Separation of the power turbine shaft retaining bolt resulting in extensive power turbine area damage and a loss of shaft output power.
- [NTSB MIA02LA133](https://openairdocs.org/ntsb/MIA02LA133.md): Bell UH-1B · Lorida, FL · Accident · Serious injuries · Limited investigation · Final report · Jul 16, 2002 · N91281 · Substantial damage
  > The pilot's continued operation with known engine anomalies resulting in loss of engine power due to failure of the engine fuel control pump drive clutch assembly due to wear and collision with the terrain during the resultant descent.
- [NTSB DEN01TA134](https://openairdocs.org/ntsb/DEN01TA134.md): Bell 205A-1 · Jackson, WY · Accident · No injuries · Final report · Jul 31, 2001 · N205BR · 2 aircraft · Substantial damage
  > the Bell 212 helicopter pilot's inadequate visual lookout which resulted in a midair collision.
- [NTSB SEA01LA046](https://openairdocs.org/ntsb/SEA01LA046.md): Western International UH-1H · Darby, MT · Accident · 1 fatal · Limited investigation · Final report · Feb 7, 2001 · N205GL · Substantial damage
  > Inflight loss of a tail rotor pitch change link-to-blade grip attach bolt, resulting partial loss of tail rotor control, and subsequent entanglement of the helicopter's external load cable with a tree during emergency descent. Factors included the pilot's…
- [NTSB MIA00LA170](https://openairdocs.org/ntsb/MIA00LA170.md): Southwest Florida SW204 · Fort Pierce, FL · Accident · No injuries · Limited investigation · Final report · May 24, 2000 · N37BA · Substantial damage
  > An in-flight separation of a tail rotor blade tip weight resulting in tail rotor assembly imbalance and separation due to the installation of an unapproved rotor blade by company maintenance personnel, and the subsequent collision with trees during an…
- [NTSB LAX99LA283](https://openairdocs.org/ntsb/LAX99LA283.md): Bell UH-1B · Lost Hills, CA · Accident · No injuries · Limited investigation · Final report · Aug 25, 1999 · N999SJ · Substantial damage
  > Failure and separation of the 90-degree gearbox as a result of the disengagement of the pinion and gear teeth. The cause(s) of the pinion and gear disengagement were undetermined.
- [NTSB FTW99WA109](https://openairdocs.org/ntsb/FTW99WA109.md): Bell UH1-B · Mexico City, Mexico · Accident · No injuries · Foreign investigation · Apr 5, 1999 · N64CC · 2 aircraft · Substantial damage
- [NTSB LAX99TA066](https://openairdocs.org/ntsb/LAX99TA066.md): Bell 205A-1 · Van Nuys, CA · Accident · Serious injuries · Final report · Jan 3, 1999 · N58126 · Substantial damage
  > A loss of engine power due to an undetermined component failure in the second stage power turbine nozzle area. Factors in the accident were the mountainous/hilly nature of the terrain and the dark night lighting conditions which precluded the pilot from…
- [NTSB SEA99LA020](https://openairdocs.org/ntsb/SEA99LA020.md): Garlick UH-1H · Darrington, WA · Accident · Serious injuries · Limited investigation · Final report · Dec 14, 1998 · N94NW · Substantial damage
  > The total separation of the vertical fin (stabilizer), as the result of fatigue cracks which initiated in the fourth rivet hole above where the fin extends from the tailboom.
- [NTSB FTW98LA405](https://openairdocs.org/ntsb/FTW98LA405.md): Bell UH-1L · Price, UT · Accident · Minor injuries · Limited investigation · Final report · Sep 19, 1998 · N5107J · Substantial damage
  > The pilot's inadvertent loss of tail rotor effectiveness. Factors were the high density altitude flight conditions, the unfavorable wind condition, and the none suitable terrain for an autorotation.
- [NTSB SEA98FA104](https://openairdocs.org/ntsb/SEA98FA104.md): Garlick UH-1H · Couer D'Alene, ID · Accident · No injuries · Field investigation · Final report · Jun 18, 1998 · N869W · Substantial damage
  > Fatigue failure of a reduction drive planetary gear. Factors include an unapproved part and plating process, and uneven terrain at the emergency landing site.
- [NTSB SEA98FA077](https://openairdocs.org/ntsb/SEA98FA077.md): Garlick UH-1H · Hope, ID · Accident · No injuries · Field investigation · Final report · May 19, 1998 · N98NW · Substantial damage
  > Failure of a misaligned main bearing in the engine. Factors include returning a previously unairworthy-tagged engine to service by the operator's maintenance personnel without sufficient information to identify and correct an unknown engine deficiency.
- [NTSB LAX98GA127](https://openairdocs.org/ntsb/LAX98GA127.md): Bell 205A-1 · Los Angeles, CA · Accident · 4 fatal · Final report · Mar 23, 1998 · N90230 · Destroyed
  > An excessive bending load applied to the tail rotor blade assembly of an undetermined origin which produced a fatigue crack, the separation of the assembly, and a forced landing. Factors were the lack of suitable terrain to perform a forced landing, the…
- [NTSB SEA98LA017](https://openairdocs.org/ntsb/SEA98LA017.md): Bell TH-1L · Canby, OR · Accident · Minor injuries · Limited investigation · Final report · Nov 25, 1997 · N8160G · Substantial damage
  > The pilot's allowance of excessive airspeed resulting in the long-line hook impacting the tail rotor, and his allowance of an airspeed bleed-off preventing a successful run-on landing due to a loss of yaw control.
- [NTSB SEA97LA198](https://openairdocs.org/ntsb/SEA97LA198.md): Garlick UH-1B · Dayville, OR · Accident · Serious injuries · Limited investigation · Final report · Aug 29, 1997 · N22753 · Substantial damage
  > Improper installation of the transmission door by a company mechanic, resulting in inflight separation of the door (which then struck the tail rotor system) and consequent total loss of the tail rotor. Contributing to the accident were: inadequate…
- [NTSB SEA97FA196](https://openairdocs.org/ntsb/SEA97FA196.md): Southern Aero UH-1B · Skykomish, WA · Accident · 1 fatal · Field investigation · Final report · Aug 27, 1997 · N896W · Substantial damage
  > A fatigue fracture in the main rotor mast, which resulted in an in flight separation of the main rotor from the helicopter. Contributing to the accident was insufficient Federal Aviation Administration airworthiness standards and requirements for the aircraft.
- [NTSB LAX97LA206](https://openairdocs.org/ntsb/LAX97LA206.md): Bell UH-1B · Heron, CA · Accident · No injuries · Limited investigation · Final report · Jun 11, 1997 · N888SJ · Destroyed
  > partial loss of engine power for undetermined reasons. A factor relating to the accident was that the engine lost power when the helicopter was outside (below) the limits of the height/velocity curve.
- [NTSB LAX97LA204](https://openairdocs.org/ntsb/LAX97LA204.md): Bell 204-B · Kaneohe, HI · Accident · No injuries · Limited investigation · Final report · Jun 6, 1997 · N64F · Substantial damage
  > failure of the pilot to verify that the load was properly rigged before attempting to pick it up. The uneven (sloping) terrain was a related factor.
- [NTSB MIA97TA139](https://openairdocs.org/ntsb/MIA97TA139.md): Bell 204-B · Calderwood, TN · Accident · No injuries · Final report · Apr 16, 1997 · N4580Y · Destroyed
  > The inadequate maintenance inspection of the helicopter resulting in loss of lubrication from the main drive shaft going undetected until failure of the drive shaft.
- [NTSB MIA97LA099](https://openairdocs.org/ntsb/MIA97LA099.md): Bell UH-1B · Labelle, FL · Accident · Minor injuries · Limited investigation · Final report · Mar 11, 1997 · N70696 · Destroyed
  > Company maintenance personnel's failure to properly evaluate a main rotor system problem resulting in main rotor straps with multiple laminates separated due to fatigue cracking being allowed to continue in service until failure and separation of a main rotor…
- [NTSB SEA97TA012](https://openairdocs.org/ntsb/SEA97TA012.md): Garlick UH-1H · Detroit, OR · Accident · Minor injuries · Final report · Oct 20, 1996 · N98NW · Substantial damage
  > the pilot's misjudgement of rotor clearance from the terrain. The proximity of the berm was a related factor.
- [NTSB SEA96FA187](https://openairdocs.org/ntsb/SEA96FA187.md): Garlick UH-1H · Coeur D'Alene, ID · Accident · Serious injuries · Field investigation · Final report · Aug 12, 1996 · N97NW · Substantial damage
  > Fatigue fracture of the left forward vertical stabilizer spar, resulting in loss of the vertical stabilizer and tail rotor and subsequent loss of control. A factor was insufficient applicability (by make and model) of an existing FAA airworthiness directive…
- [NTSB LAX95LA075](https://openairdocs.org/ntsb/LAX95LA075.md): Kaman HH43 · Glendale, AZ · Accident · No injuries · Limited investigation · Final report · Jan 10, 1995 · N321WN · Substantial damage
  > The pilot's failure to maintain an adequate visual lookout to avoid a collision with a tree during an aerial application swath run.
- [NTSB ATL94LA180](https://openairdocs.org/ntsb/ATL94LA180.md): Bell UH-1B · Ozark, AL · Accident · Minor injuries · Limited investigation · Final report · Sep 29, 1994 · N41870 · Substantial damage
  > The failure of the engines' main bearings because of a lack of lubrication. A factor was the heavily wooded terrain.

Next page: https://openairdocs.org/ntsb.md?engine=41552&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 ('41552', '41549', '41587'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=41552

---
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.