C172 student pilot and instructor reported a taxiway excursion into the grass due to the brakes malfunctioning during taxi.
Synopsis
C172 student pilot and instructor reported a taxiway excursion into the grass due to the brakes malfunctioning during taxi.
Narrative
I was a student pilot in flight training with my flight instructor. We had intentions to do an instrument flight in the local area. We did a normal start-up and taxi. We made sure to do a brake check before taxing to Runway XX. We got clearance to taxi everything was working fine. Upon reaching Taxiway 1 I noticed that we were right of the Taxiway so I immediately applied left rudder and nothing happened. Nothing was happening; and we were speeding up to about 8-10 kts. I immediately advise my Instructor that the brakes were not working and he applies full brakes. The plane just turned right into the grass in between the taxi lights. The plane was about 6 to 10 ft. off the Taxiway. At the time our ground speed was 10 kts. My Instructor immediately advises ground that we left the Taxiway and there was no physical damage to any Taxiway lights; airport surfaces; or the plane itself. The Chief Flight Instructor was notified along with ground operations. The aircraft was taxied to maintenance where it is being diagnosed.
Second reporter narrative
I was serving the role as a Flight Instructor. We were going to do instrument flight training in the local area. We did a normal start-up and taxi. Advised ground of our location and received our taxi clearance. Both the Student Pilot and I did a successful brake check before starting our taxi. The Student Pilot taxied the aircraft and felt no abnormalities. upon reaching Taxiway 1 there is a slight left turn to proceed to our run-up area. The Student advised something wasn't right and attempted to slow down. The aircraft started to pull to the right when the brakes were applied. I applied full brakes to attempt to stop the aircraft before leaving the taxiway. The aircraft continued to the right and proceeded off the taxiway by 6-10 ft. At the time our ground speed was about 10 kts. I advised ground we had left the Taxiway and there was no physical damage to any taxiway lights; airport surfaces or the plane itself. The Chief flight Instructor was notified along with ground operations. The aircraft was taxied to maintenance where it is being diagnosed.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.