The pilot of a C172 experienced asymmetrical braking for unknown reason during landing that resulted...

Attributes
ACN	1297323
Time
Date	201509
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Landing
Flight Plan	VFR
Component
Aircraft Component	Normal Brake System
Person 1
Function	Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 8 Flight Crew Total 125 Flight Crew Type 70
Events
Anomaly	Aircraft Equipment Problem Less Severe Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Runway

Narrative:

Upon landing on runway with mild variable winds; VFR weather; touched down within recommended speeds. Brought full back pressure on controls; experienced unilateral braking to right wheel; resulting in aircraft turning in direction of area between runway and taxiway. Additional braking applied to left wheel to attempt to straighten course of aircraft without success. Aircraft proceeded to enter gravel ditch between runway and taxiway. Back pressure continuously applied to maintain nose-up position throughout incident so as to avoid prop strike. Aircraft brought to complete stop in gravel area prior to entry onto taxi-way; no runway/taxiway incursion.

Original NASA ASRS Text

Title: The Pilot of a C172 experienced asymmetrical braking for unknown reason during landing that resulted in a runway excursion.

Narrative: Upon landing on runway with mild variable winds; VFR weather; touched down within recommended speeds. Brought full back pressure on controls; experienced unilateral braking to R wheel; resulting in aircraft turning in direction of area between runway and taxiway. Additional braking applied to L wheel to attempt to straighten course of aircraft without success. Aircraft proceeded to enter gravel ditch between runway and taxiway. Back pressure continuously applied to maintain nose-up position throughout incident so as to avoid prop strike. Aircraft brought to complete stop in gravel area prior to entry onto taxi-way; no runway/taxiway incursion.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

The pilot of a C172 experienced asymmetrical braking for unknown reason during landing that resulted in a runway excursion.