# Compressor bleed valve

- Type: NTSB finding subsection
- Path: [Aircraft](https://openairdocs.org/ntsb-findings/01) › [Aircraft power plant](https://openairdocs.org/ntsb-findings/0105) › [Engine bleed air system](https://openairdocs.org/ntsb-findings/010575) › Compressor bleed valve
- NTSB code: 01057532
- Cases: 4
- In the probable cause: 4
- Fatal cases: 0
- All cases: https://openairdocs.org/ntsb-findings/01057532/cases.md
- Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/01057532/cases.md?cause=1
- Page: https://openairdocs.org/ntsb-findings/01057532

## Cases per year (in the probable cause / all)

- 2016: 2 / 2
- 2017: 1 / 1
- 2024: 1 / 1

## Defining events in these cases

- [Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342): 2 cases
- [Loss of engine power (total)](https://openairdocs.org/ntsb-events/341): 1 cases
- [Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150): 1 cases

## Aircraft models (registry)

- [Bombardier CL-600-2C11](https://openairdocs.org/model/bombardier-cl-600-2c11): 1 cases
- [Bell OH-58A](https://openairdocs.org/model/bell-oh-58a): 1 cases
- [Air Tractor AT-602](https://openairdocs.org/model/air-tractor-at-602): 1 cases
- [Air Tractor AT-502A](https://openairdocs.org/model/air-tractor-at-502a): 1 cases

## Other findings in the same cases

- [Installation](https://openairdocs.org/ntsb-findings/02062035) (Personnel issues): 1 cases
- [Scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010) (Personnel issues): 1 cases
- [Decision making/judgment](https://openairdocs.org/ntsb-findings/02041520) (Personnel issues): 1 cases
- [Engine bleed air system, general](https://openairdocs.org/ntsb-findings/01057500) (Aircraft): 1 cases
- [Nacelle/pylon misc structure](https://openairdocs.org/ntsb-findings/01035420) (Aircraft): 1 cases
- [Scheduled maint checks](https://openairdocs.org/ntsb-findings/01010520) (Aircraft): 1 cases

## Newest cases

- [NTSB WPR24LA070](https://openairdocs.org/ntsb/WPR24LA070), Jan 10, 2024: Air Tractor AT-502A (N6126U), Stratford, CA, substantial damage. Probable cause: A partial loss of engine power due to the malfunction of the engine compressor bleed-off valve.
- [NTSB DCA17LA182](https://openairdocs.org/ntsb/DCA17LA182), Jul 2, 2017: Bombardier CL 600 2C10 (N796SK), Denver, CO, substantial damage. Probable cause: The fuel supply tube fitting pulling out of the left engine’s operability bleed valve (OBV) during the landing rollout, allowing fuel to leak and contact hot engine cases, which ignited a fire that…
- [NTSB WPR17LA042](https://openairdocs.org/ntsb/WPR17LA042), Dec 27, 2016: Air Tractor AT 602 (N602L), Willows, CA, substantial damage. Probable cause: The decision of the maintenance facility mechanic to conduct maintenance without reference to the applicable manufacturer’s guidance, which resulted in the improper reassembly and subsequent failure…
- [NTSB WPR16LA134](https://openairdocs.org/ntsb/WPR16LA134), Jul 2, 2016: Bell OH 58A (N6251G), Brawley, CA, substantial damage. Probable cause: The engine's degraded performance due to excessive wear of the engine bleed valve, which prevented it from closing during the accident flight. Contributing to the accident was the operator's failure…

NTSB has coded findings and defining events since 2008; earlier cases used its older occurrence and cause codes and aren't counted.

Findings: https://openairdocs.org/ntsb-findings.md. Defining events: https://openairdocs.org/ntsb-events.md. Phases of flight: https://openairdocs.org/ntsb-phases.md. Every investigation, filtered by finding, event, phase, state, year or model: https://openairdocs.org/ntsb.md (for example ?state=MI&fatal=1).

NTSB's definitions: Accident and incident, 49 CFR 830.2 (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-VIII/part-830/subpart-A/section-830.2), CICTT occurrence categories (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/OccurrenceCategoryDefinitions.pdf), CICTT phases of flight (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/PhaseofFlightDefinitions.pdf), and NTSB coding manual, before 2008 (PDF) (https://www.ntsb.gov/GILS/Documents/codman.pdf). NTSB publishes no definitions for its findings, only their names.

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