What happened
A tailwheel-equipped airplane, which had recently undergone a 100-hour inspection by a contract maintenance facility, was landing on a gravel runway. During the flight, the pilot used a short piece of tubing to direct heated air toward his feet. Upon touchdown, the pilot found that the brakes were locked. This caused the tires to skid across the gravel surface, leading to the left wing striking the ground.
The investigation
The investigation focused on the aircraft's braking system, which uses separate master cylinder and brake pedal assemblies for each main wheel. These cylinders are located on the cockpit floor next to the rudder pedals and are serviced by adding hydraulic fluid through small caps on top of each cylinder.
Following the accident, the brakes remained in a locked state for approximately two hours. However, after this period, the wheels were observed to turn normally. Maintenance personnel from the operator provided information regarding the potential cause of the malfunction.