WPR24LA045 · Cessna 170B
Cessna 170B · Accident: loss of control on ground during landing
From Sacramento Mather Airport (MHR) to an unrecorded destination
Event
- NTSB case
- WPR24LA045
- 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
- Event fatalities
- Unknown
- 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
Cessna 170B
- Aircraft type
- Cessna 170
- 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
- N170HT
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Sacramento Mather Airport (MHR), Rancho Cordova, CATo not recorded
- Aircraft age
- About 71 years (built 1952)
- 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
- Defining eventThe 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
- Loss of control on ground
- 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
- Aircraft › Aircraft systems
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was landing at his destination airport when the airplane veered to the left after touchdown. . The pilot attempted to correct the movement and turn the airplane back to the runway centerline with the addition of power and right rudder inputs, but the airplane then veered to the right and departed the right side of the runway. The pilot did not recall experiencing any mechanical anomalies with the brakes during the accident flight and observed normal resistance during the landing. Postaccident examination of the brake system revealed that the right brake master cylinder failed to release pressure twice during testing and the piston had to be manually lifted before the cylinder would release pressure, which the pilot was unlikely to have been able to do during landing. The seized brake master cylinder was likely due to a deformed return spring that had bowed at some point during its service life. The manufacturer reported that the failure of the cylinder to release pressure would have resulted in a locked brake. Although the pilot could not recall if he applied brakes, both his and the witness’ recollection that the airplane abruptly turned right and departed the runway suggests that he may have applied right brake as the airplane was veering left. During this time the piston likely failed to release pressure due to the faulty return spring, which resulted in a runway excursion.
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
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR24LA045
- Event ID
- 20231129193449
- Case number
- WPR24LA045
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: investigation status, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: edf74b630f7bcce509909840be746c5585d9b8dc263fd8446e2663a1ede8c7b4; retrieved 2026-09-16T18:19:47.713Z.