PA22 pilot and passenger reported losing control of the aircraft and striking a ground service installation after refueling when there was an apparent brake failure.
Synopsis
PA22 pilot and passenger reported losing control of the aircraft and striking a ground service installation after refueling when there was an apparent brake failure.
Narrative
Had just finished fueling the aircraft at the airport's self serve fuel station. Completed before start checklist; including setting parking break; and starting aircraft checklist in order to taxi it to the main ramp where it would be parked and secured for that night with a departure the following day. Shortly after the aircraft was successfully started; though the parking brake was still engaged; the aircraft began rolling forward and entered a turn to the left. Immediately executed corrective actions of pulling the brake lever and applying right rudder. Aircraft then entered a sharp left turn and the propeller collided with a decommissioned self serve air compressor box mounted on a pole. The propeller immediately stopped and then completed appropriate shut down checklist. Once the aircraft was safely secured; conferred with the passenger who stated the brake was indeed being fully applied and noticed the right rudder was also being fully utilized in an effort to steer away from obstacles. An attempt was made to cease propeller rotation before collision through mixture cutoff and shutting off both magnetos. After assessing the damage; both the passenger and I tested the brakes by hand pulling the aircraft away from the decommissioned air compressor box with the parking brake still fully enabled. The aircraft still moved very easily with the parking brake still set. There were no noticeable human factors contributing to this outcome as well as no visible peculiarities were noticed both during the thorough pre-flight to ZZZ and a walk around before commencing taxiing to the main ramp; as well as during damage assessment. Both passenger and I came to the same conclusion that this occurrence resulted from braking anomalies.
Second reporter narrative
Finished fueling up the aircraft; on start up to taxi the aircraft to parking for the night; the aircraft had no braking authority and collided with an inoperative wall-mounted air compressor unit.PIC finished going through start up procedure and after starting engine the aircraft began to immediately roll forward veering towards the left. I then watched as the PIC pulled the throttle all the way to idle and then reach for the hand brake. I also observed and double checked the parking brake was still engaged; which it was. The hand brake was pulled back all the way to full braking multiple times with no reaction from the aircraft. The aircraft continued to loop towards the left side and worsened with braking; it gave the appearance as if only the left brake was properly engaging causing the aircraft to loop left. During this time; while not making flight control inputs in any way; I hovered over the rudder pedals and felt the PIC pushing hard right rudder with no change to the movement direction. As the PIC was already taking corrective actions; I stayed off flight controls. After observing PIC pull throttle to idle and pull the handbrake with no change in aircraft movement; I also pulled the throttle and hand brake to full brake to verify both controls were not slowing the aircraft. The PIC then pulled the mixture to shut down the engine; but the momentum of the aircraft carried and the spin of the propeller did not finish before colliding with the air compressor box. While the PIC commenced the shutdown and securing checklist; I once again verified that the parking brake was fully set. Shortly after investigating the damages afterward; the PIC and I verified that even with the parking brake set; the brakes were not engaging by easily pushing the aircraft away from the pillar despite full braking inputs from the PIC sitting in the aircraft while the engine was not running. There were no noticeable human factors that would contribute to this outcome; yet both the PIC and I decided there was some sort of brake issue.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.