Air carrier technicians reported while preparing to replace a MLG tire they released the brakes and the aircraft rolled due to chocks being removed.
Synopsis
Air carrier technicians reported while preparing to replace a MLG tire they released the brakes and the aircraft rolled due to chocks being removed.
Narrative
I was working on a routine overnight inspection for Aircraft X at DCA while it was on a gate. Me and two other co-workers saw that we had a main landing gear tire to change and a Inbound issue that we needed to change both nose landing gear tires. After performing an oil servicing task on engine Person A came up to me and discussed that he would do the walk around and Person B would change the main tire; and asked if I could go up and start the paperwork. I went up stairs through the jet bridge to get to the aircraft. Person B who was down by the MLG called up to me while I was halfway up the stairs saying that he was ready for me to release the brakes. I went up into the aircraft; applied power and waited for the flight control power up test to finish. When the (P-BIT) Power-on Built-in Test finished I proceeded to release the parking brake. I then felt the plane move more than it should have; which later was found to be that the aircraft had moved back less than a foot and stopped. I went down the jet bridge over to where my coworkers Person B and Person A were to find that Person A had removed all of the chocks from the nose landing gear from and main landing gear before telling me to release the brake and had placed a chock down behind the main landing gear that he had been getting ready to work on after he noticed it move more than it should have. I went back upstairs inspected the area around the forward passenger door; I then went back downstairs to talk with my co-workers about what had happened. After talking I found out that Person B had removed the chocks on the R/H MLG which he was about to start changing a tire on and the nose landing gear from which we had an inbound issue to take care of. Person B had not checked the L/H MLG to see if there were chocks on those tires before telling me to release the parking brake. I was unaware that the chocks had been removed when I released the parking brake after having been told to release the parking brake when I went upstairs. When we were downstairs discussing the event I notified my shift supervisor Person C about what had occurred. He called Operations to get them to move the jet bridge back into position. Person C also inspected the plane. Our supervision told us when we got back to the office to file a report for what had happened. We saw no damage to the aircraft or to equipment. All personal were not injured.
Second reporter narrative
On the aircraft listed above I was going to change a MLG tire which requires the brakes to be released. I pulled the chocks from under the RH MLG tire so the aircraft would not catch them when we lower the aircraft after removal and replacement of the tires. I also to try to save time was preparing the NLG tires to be replaced as well and removed the NLG chocks. Just as I was about to start jacking the aircraft from the MLG I told 1 of my co-workers to release the break. I finished setting up for the MLG tire to begin jacking and the brakes were released. The plane began to roll back a bit from where it was parked and I kept calm and placed one of the MLG chocks right behind the tire I was about to begin working on and the plane came to a stop. After looking over how far the aircraft had moved from its original parking spot which is about a little under a foot I told my co-workers that we should probably contact our supervisor to let him know what had happened. After looking everything over we noticed nothing had been damaged on the aircraft; tools; or equipment. It could have been a lot worse. Thankfully it wasn't and I now have learned to not try to speed things up from the maintenance manual directions.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.