# NTSB investigations: Lycoming IO-540-AE1A5: Sys/Comp malf/fail (non-power)

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 CEN25LA326](https://openairdocs.org/ntsb/CEN25LA326.md): Robinson Helicopter R44 II · Cape Girardeau, MO · Accident · No injuries · Class 3 · Limited · Preliminary report · Aug 16, 2025 · N24DF · Substantial damage
  > On August 16, 2025, at 1150 central daylight time, a Robinson R44 II helicopter, N24DF was substantially damaged when it was involved in an accident near Cape Girardeau, Missouri. The pilot and three passengers were not injured. The helicopter was operated as…
- [NTSB CEN19LA240](https://openairdocs.org/ntsb/CEN19LA240.md): Robinson R44 · Blair, NE · Accident · Minor injuries · Class 3 · Limited · Final report · Jul 27, 2019 · N7508Z · Substantial damage
  > The failure of the lower actuator bearing support bracket, which resulted in the misalignment of the clutch actuator, the loss of belt tension on the main rotor drive system, and the subsequent forced landing on sloped terrain.
- [NTSB WPR17LA159](https://openairdocs.org/ntsb/WPR17LA159.md): Robinson Helicopter R44 II · Van Nuys, CA · Accident · Serious injuries · Limited investigation · Final report · Jul 21, 2017 · N3254E · Substantial damage
  > An improper repair of the right magneto's tachometer and governor signal wire, which failed during cruise flight and initiated a simultaneous malfunction of both the engine tachometer and governor control system, which resulted in erroneous and contradictory…
- [NTSB CEN15LA198](https://openairdocs.org/ntsb/CEN15LA198.md): Robinson Helicopter R44 II · Dunlap, IL · Accident · No injuries · Limited investigation · Final report · Apr 15, 2015 · N754R · Substantial damage
  > A loss of main rotor rpm for reasons that could not be determined during postaccident examinations.
- [NTSB DFW08TA092](https://openairdocs.org/ntsb/DFW08TA092.md): Robinson R44 · Topeka, KS · Accident · No injuries · Final report · Apr 5, 2008 · N402PD · Substantial damage
  > A malfunctioning magneto, resulting in a high engine rpm and low rotor warning indications. A contributing factor was the impact with a light pole, during the precautionary landing.

## 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 ('41899')
    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" = '330'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-events/330/cases?engine=41899

---
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.