EMB-505 flight crew reported the emergency brake system failed to stay pressurized after parking and the aircraft began to roll backwards. The Captain started the engine to restore brake pressure while the First Officer left the aircraft to install chocks on the nose gear.
Synopsis
EMB-505 flight crew reported the emergency brake system failed to stay pressurized after parking and the aircraft began to roll backwards. The Captain started the engine to restore brake pressure while the First Officer left the aircraft to install chocks on the nose gear.
Narrative
Day 0 I arrived at ZZZ1 where aircraft was located. Maintenance has just been performed and I'm unsure what specific task had been completed. The aircraft was pulled to the front of the FBO; electrical power was applied and I noticed the emergency brake accumulator was depleted; common to see after maintenance is performed. During engine start; emergency brake accumulator charged as normal. No issues noted. A few min after takeoff the Captain and I received a Crew Alert System (CAS) message that the emergency brake low pressure. Captain (PNF) reviewed the QRH which mentioned to chock the aircraft after landing. She also reviewed the MEL and the emergency brake accumulator was not listed. She contacted maintenance by phone and discussed options; the plan was to continue to ZZZZ. She also contacted the Chief Pilot via text and he mentioned to continue. Person A mentioned to the Chief Pilot that we will need to be chocked in ZZZZ when we land and to ensure ground personnel would be there to do such task. Landing in ZZZZ the emergency brake accumulator charged itself after touchdown and when we stopped at the parking spot we had a good parking brake. Departing ZZZZ the same took place; no emergency accumulator brake pressure and during engine start it charged. 5 to 10 min after takeoff we got the CAS message. Landing in ZZZ the emergency brake accumulator charged itself and we had parking brakes. We taxied to the US custom area and parked with instruction not to get out of the aircraft. Pulling to the assigned spot I set the brake and no agents or line guys were there to chock us. While in the aircraft; I started looking for chocks just in case the aircraft started to roll. At the first sign of movement I jumped out and chocked the nose. By the time the chocks were in; the aircraft had rolled 10 or so feet backwards. The aircraft did not cause issues with other aircraft not touch any objects. Captain started 1 engine and taxied it forward and I chocked the nose. During this time the US Custom and Border Patrol was there. I mentioned that I was sorry to get out of the aircraft but I had to chock the nose to keep it from rolling. He understood. A few moments later an airport safety rep came and took my statement. He had heard an aircraft had rolled a few feet back after shutdown. He also took a picture of my work badge and I explained to him there was no one to chock the aircraft nose and we were instructed not to get out of the aircraft and that I took it upon myself to get out and chock the nose. He understood. After customs cleared our passengers; we started and taxied to the FBO for fuel then depart to ZZZ2. Arriving at ZZZ2 the ground worker was there and chocked the nose after shutdown.
Second reporter narrative
On a charter flight from ZZZ1 to ZZZZ we received a 'Emergency Brake Low Pres' crew alerting message approximately five minutes after departure. I was PNF and performed the QRH procedure which basically stated to make sure the plane is chocked upon landing. I called our maintenance department while in the air to determine if we should return or continue the flight. There was no MEL prohibiting the flight to continue so we landed in ZZZZ. Upon landing and taxiing in to park the pressure came back up. After departure the Crew Alert System (CAS) message reappeared and we continued our flight to ZZZ and taxied to the customs clearing area to await border patrol to arrive. I failed to realize that we were not chocked and after a while the plane started to roll backwards. Co-pilot jumped out to run for chocks but he was unable to get the plane chocked so I started an engine to move the plane back into position. The plane rolled into a taxi lane in the nonmovement area without ground ramp clearance. Our parking brake pressure did not hold the plane in place.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.