NTSB investigations: Allison 250-C20 series

14 cases on aircraft whose registry engine model is Allison 250-C20 series, where the defining event was Low altitude operation/event. Aircraft are matched to the registry by N-number and event date, checked against the reported serial number, make and model, so older matches can be wrong.

Cases per year

20112026
NTSB investigations: Allison 250-C20 series per year, 2011–2026: 14 cases
20112
20121
20132
20141
20172
20181
20213
20221
20231

Latest cases

Query with SQL
duckdb -csv -c "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')
      AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e WHERE e.case_mkey = x.case_mkey AND e.aircrafts_position = x.position AND e.\"isDefiningEvent\" AND e.\"tier2Number\" = '220'))
  ORDER BY c.\"eventDate\" DESC, c.\"ntsbNumber\" DESC"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

NTSB CEN23LA279Accident · No injuriesClass 4 · LimitedFinal reportBell 206B · Chapman, KSThe pilot’s failure to maintain clearance from the power line during an agricultural application pass.Jul 5, 2023 · N67FA · Substantial damageNTSB ERA22LA206Accident · Minor injuriesClass 4 · LimitedFinal reportBell 206 · Lake Apopka, FLA collision with water following a loss of visual reference to the water surface due to sun glare.Apr 26, 2022 · N206BX · Substantial damageNTSB CEN21LA356Accident · Serious injuriesClass 4 · LimitedFinal reportBell 206 · Corydon, INThe pilot’s failure to see and avoid power lines.Aug 4, 2021 · N59552 · Substantial damageNTSB ERA21LA269Accident · 1 fatalClass 3 · LimitedFinal reportGarlick Helicopters OH-58A+ · Alpine, ALThe 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.Jun 25, 2021 · N372NS · Substantial damageNTSB ERA21LA262Accident · Serious injuriesClass 3 · LimitedFinal reportMcdonnell Douglas Helicopter 369E · Swan Lake, NYThe 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…Jun 18, 2021 · N371EE · Substantial damageNTSB CEN19FA020Accident · 1 fatalClass 2 · FieldFinal reportHughes 369 · McDougal, ARThe 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.Nov 2, 2018 · N5187S · DestroyedNTSB CEN17LA314Accident · Serious injuriesLimited investigationFinal reportHughes 369D · Villa Grove, COThe pilot’s failure to maintain main rotor clearance from a power line tower during low-level maneuvering.Aug 10, 2017 · N58424 · Substantial damageNTSB GAA17CA402Accident · No injuriesData collectionFinal reportBell 206 · Uniontown, KYThe pilot's failure to maintain adequate separation from power lines, which resulted in a loss of helicopter control.Jun 30, 2017 · N60KH · Substantial damageNTSB ERA15CA055Accident · No injuriesData collectionFinal reportMcdonnell Douglas Helicopter MD500 · Decatur, ALAn undetermined pilot's failure to maintain clearance from an electrical transmission tower resulting in substantial damage to a main rotor blade. Postaccident investigation could not determine which of two pilots was flying the helicopter at the time the…Nov 18, 2014 · N8371F · Substantial damageNTSB WPR13LA358Accident · Minor injuriesLimited investigationFinal reportBell 206B · Chualar, CAMaintenance personnel's failure to properly tighten the bolts securing the main driveshaft to the transmission, which resulted in fatigue failure of the bolts and disconnection of the driveshaft during low-altitude flight.Aug 4, 2013 · N90146 · Substantial damageNTSB WPR13GA128Accident · 1 fatalFinal reportBell 206B · Eureka, NVThe pilot’s failure to maintain clearance from a wire while maneuvering during low-altitude operations. Contributing to the accident was task- and/or work-related fatigue.Feb 18, 2013 · N20620 · Substantial damageNTSB CEN12CA319Accident · Serious injuriesData collectionFinal reportHughes 369HS · Delavan, MNThe pilot’s failure to maintain clearance with power lines during an aerial application flight.May 25, 2012 · N11ZX · Substantial damageNTSB CEN11CA533Accident · No injuriesData collectionFinal reportGarlick Helicopters OH-58C · Rushford, MNThe pilot's diverted attention, which resulted in the failure to maintain clearance from the power line.Jul 31, 2011 · N82855 · Substantial damageNTSB CEN11CA509Accident · No injuriesData collectionFinal reportBell 206B · Temple, OKThe pilot’s failure to maintain clearance from static power lines.Jul 23, 2011 · N118TV · Substantial damage