SEA03LA066 · Maule MX-7-235
Maule MX-7-235 · Accident: airframe, component or system failure during landing
From Jack A Buell Airport (S72) to Plummer, ID
Event
- NTSB case
- SEA03LA066
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Maule MX-7-235
- Aircraft type
- Maule MX-7
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N114MK
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Jack A Buell Airport (S72), Saint Maries, IDTo Plummer, ID
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Landing · landing roll
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Landing gear, normal brake system › Locked
- Landing gear, parking brake › Jammed
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
During the last part of the landing roll, as the pilot was applying the brakes, the left main gear brake locked up, resulting in the tailwheel-equipped aircraft pulling hard to the left. As he tried to bring the aircraft to a stop, it nosed over onto its back. It was ultimately determined that the parking brake lock activation tab on the left brake master cylinder became stuck on the master cylinder plunger rod, resulting in a situation where the pilot was unable to reduce braking pressure on the left side. A further inspection of the system revealed that there was a burr on the master cylinder shaft. When the left brake was applied and then released, the burr lifted the parking brake locking tab, through which the cylinder shaft passes, and the spring that should press the tab back down to the unlocked position was unable to do so. This resulted in the failure of the brake to release, and it therefore remained locked in whatever had been its most fully-applied position. The malfunction was able to be duplicated during a post-accident inspection/test of the system.
Probable cause
The jamming of the left parking brake locking tab on a burr on the left brake master cylinder activation rod during the landing roll, resulting in the left brake becoming locked in a position where excessive braking was applied.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA03LA066
- Event ID
- 20030425X00567
- Case number
- SEA03LA066
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2003-04-20.
- API snapshot SHA-256: 9f99c9c423464bc488261b5f3ea584048b72a1f7f1324c1187694440d55171a6; retrieved 2026-09-22T09:22:47.435Z.