# Master cylinder/brake valve

- Type: NTSB finding subsection
- Path: [Aircraft](https://openairdocs.org/ntsb-findings/01) › [Aircraft systems](https://openairdocs.org/ntsb-findings/0102) › [Landing gear system](https://openairdocs.org/ntsb-findings/010232) › Master cylinder/brake valve
- NTSB code: 01023243
- Cases: 21
- In the probable cause: 20
- Fatal cases: 0
- All cases: https://openairdocs.org/ntsb-findings/01023243/cases.md
- Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/01023243/cases.md?cause=1
- Page: https://openairdocs.org/ntsb-findings/01023243

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

- 2009: 1 / 1
- 2011: 2 / 2
- 2013: 3 / 3
- 2015: 2 / 2
- 2016: 4 / 4
- 2017: 4 / 4
- 2020: 1 / 1
- 2022: 1 / 2
- 2023: 1 / 1
- 2025: 1 / 1

## Defining events in these cases

- [Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330): 9 cases
- [Loss of control on ground](https://openairdocs.org/ntsb-events/230): 6 cases
- [Miscellaneous/other](https://openairdocs.org/ntsb-events/900): 2 cases
- [Runway excursion](https://openairdocs.org/ntsb-events/300): 1 cases
- [Ground collision](https://openairdocs.org/ntsb-events/200): 1 cases
- [Nose over/nose down](https://openairdocs.org/ntsb-events/096): 1 cases
- [Abnormal runway contact](https://openairdocs.org/ntsb-events/090): 1 cases

## Aircraft models (registry)

- [Piper PA-31P](https://openairdocs.org/model/piper-pa-31p): 1 cases
- [Dassault FALCON 2000](https://openairdocs.org/model/dassault-falcon-2000): 1 cases
- [Aviat A-1B](https://openairdocs.org/model/aviat-a-1b): 1 cases
- [Chance Vought F4U-5](https://openairdocs.org/model/chance-vought-f4u-5): 1 cases
- [Champion 7GCBA](https://openairdocs.org/model/champion-7gcba): 1 cases
- [Cessna 310G](https://openairdocs.org/model/cessna-310g): 1 cases
- [Cessna 305A](https://openairdocs.org/model/cessna-305a): 1 cases
- [Cessna 208B](https://openairdocs.org/model/cessna-208b): 1 cases
- [Cessna T210J](https://openairdocs.org/model/cessna-t210j): 1 cases
- [Cessna A185F](https://openairdocs.org/model/cessna-a185f): 1 cases

## Other findings in the same cases

- [Directional control](https://openairdocs.org/ntsb-findings/01062020) (Aircraft): 7 cases
- [Aircraft control](https://openairdocs.org/ntsb-findings/02063040) (Personnel issues): 3 cases
- [Brake](https://openairdocs.org/ntsb-findings/01023242) (Aircraft): 3 cases
- [Forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035) (Personnel issues): 2 cases
- [Equipment manufacture](https://openairdocs.org/ntsb-findings/04013010) (Organizational issues): 1 cases
- [Gusts](https://openairdocs.org/ntsb-findings/03034045) (Environmental issues): 1 cases
- [Conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030) (Environmental issues): 1 cases
- [Ground vehicle](https://openairdocs.org/ntsb-findings/03022025) (Environmental issues): 1 cases
- [Sign/marker](https://openairdocs.org/ntsb-findings/03022015) (Environmental issues): 1 cases
- [Use of checklist](https://openairdocs.org/ntsb-findings/02063030) (Personnel issues): 1 cases

## Newest cases

- [NTSB CEN25LA264](https://openairdocs.org/ntsb/CEN25LA264), Jul 20, 2025: Alon A2 (N6557Q), Pipestone, MN, substantial damage. Probable cause: The failure of the left brake to release due to corrosion and pitting of the caliper piston and bore, which resulted in a runway excursion.
- [NTSB WPR24LA045](https://openairdocs.org/ntsb/WPR24LA045), Nov 27, 2023: Cessna 170B (N170HT), Cameron Park, CA, substantial damage. Probable cause: A failure of the right brake master cylinder piston due to a faulty return spring, which resulted in a seized right main landing gear brake and a runway excursion
- [NTSB WPR22LA324](https://openairdocs.org/ntsb/WPR22LA324), Aug 23, 2022: Champion 7GCBA (N9512S), Athol, ID, substantial damage. Probable cause: The failure of the right brake due to a disconnected master cylinder piston rod, which led to the departure of the airplane from the runway surface. Contributing to the accident was the mechanic’s…
- [NTSB ERA22LA132](https://openairdocs.org/ntsb/ERA22LA132), Feb 11, 2022: Cessna 140 (N2509N), New Bern, NC, substantial damage. Probable cause: The loss of brake pressure on the left brake due to a failed O-ring seal.
- [NTSB ERA21LA044](https://openairdocs.org/ntsb/ERA21LA044), Nov 14, 2020: Cessna 305 (N5179G), Ellenville, NY, substantial damage. Probable cause: The failure of the right brake master cylinder lock seal spring washer.
- [NTSB GAA18CA022](https://openairdocs.org/ntsb/GAA18CA022), Oct 22, 2017: Aviat A1 (N337AM), Williamsport, PA, substantial damage. Probable cause: The pilot’s failure to verify that the parking brake was disengaged before landing, which resulted in a runway excursion.
- [NTSB WPR18LA009](https://openairdocs.org/ntsb/WPR18LA009), Oct 15, 2017: Barber Warren D Turbine Cubs P A 18 (N181TJ), Skull Valley, UT, substantial damage. Probable cause: The activation of the wheel brakes during landing, which resulted in a nose-over. The reason for the wheel brake activation could not be determined.
- [NTSB ERA17LA290](https://openairdocs.org/ntsb/ERA17LA290), Aug 20, 2017: Cessna 180 (N1585C), Newport, NH, substantial damage. Probable cause: A leak in the right brake slave cylinder, which led to no fluid in the reservoir and subsequent asymmetric braking.
- [NTSB GAA17CA212](https://openairdocs.org/ntsb/GAA17CA212), Mar 28, 2017: Thomas Craig E Wittman W-10 (N13XZ), Stevensville, MT, substantial damage. Probable cause: The pilot’s decision to take off with a known master brake cylinder leak and his subsequent failure to maintain directional control during landing.
- [NTSB ANC17LA005](https://openairdocs.org/ntsb/ANC17LA005), Nov 12, 2016: Cessna A185 (N4918Q), Ninilchik, AK, substantial damage. Probable cause: A loss of brake system fluid due to leaks in the o-rings, which resulted in asymmetrical braking and a subsequent loss of directional control during the landing roll.

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.

---
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.