Air carrier crew reported while taxing into the gate the ground crew did not chalk the aircraft resulting in the aircraft making an uncommanded movement. The Air crew was able to apply the brakes and have the aircraft re positioned for the arrival to the gate.
Synopsis
Air carrier crew reported while taxing into the gate the ground crew did not chalk the aircraft resulting in the aircraft making an uncommanded movement. The Air crew was able to apply the brakes and have the aircraft re positioned for the arrival to the gate.
Narrative
After a normal taxi in; and shutdown at the gate at LAX at approx XA45 local time; (I was Relief Pilot on this sequence); the Captain and FO (First Officer) performed the shutdown and secure checklists. After completion of the checklists; with the parking brake set; we departed the cockpit to exit the aircraft. After several minutes; with the jet bridge not mating up to the aircraft; we returned to the cockpit to inquire why we were not deplaning. As I was contacting ops; I got the sensation of movement; and as I realized we were moving backwards; I spoke to the Captain (I was occupying the FO's seat; he was in the lav); 'We're rolling!'; and as I was about to press the toe brakes; the Captain turned on the hydraulic pumps; applied brakes and stopped the aircraft; very quickly. We were obviously VERY concerned at this point; and the Captain tried to contact ground personnel via the intercom to no avail; no one was 'downstairs'. After contacting ramp; we learned that we were not deplaning as we were not (obviously) chalked. During this time; ground personnel then chalked the airplane (I had opened the FO's window and flagged down a passing cart driver whom informed me the airplane was now; indeed; chalked.) The Captain then spoke with a ground supervisor who informed us that no one had been hurt during the movement; and that the aircraft and equipment were not damaged. Much relieved; we maintained communication while the ground personnel while they repositioned the aircraft for parking. After being assured the aircraft and ground personnel were safe; and undamaged; we departed the aircraft. Cause: Before parking at the gate; a nearby aircraft had pushed and apparently the ground personnel intended to use their chalks. After the aircraft was off the gate; and we subsequently parked; the aircraft's chalks were not used to chalk our aircraft. No chalks were placed on our aircraft apparently. This event greatly concerned us as an uncommanded movement in an aircraft our size; could cause tremendous damage and injure or kill people. Suggestion: I would think that with every aircraft arrival; the aircraft should remain attached to the tug; or chalked; without fail every time.
Second reporter narrative
Aircraft rolled back 5 or 6 feet. LAX on Day 0; Captain and Relief Pilot.Landed early and waited for a plane to be pushed back out of our arrival gate. When the aircraft was clear we proceeded to the gate; we had two wing walkers and the electronic guidance displayed. We stop and set brakes according to the guide at XA45. We completed all of our shutdown checklists and saw that the two aft baggage doors were open and assumed we were chocked and secured. We collected our stuff to leave the cockpit and realized the jetbridge was not moving at XB00z. The Relief Pilot called LAX operations and I reset the brakes and the plane started to roll back; with no hydraulic pressure the brakes did not work; I turned on the electric hydraulics and was able to stop the aircraft. At the same time operations told us the airplane was NOT chocked so the jet bridge could move until aircraft was chocked. After we were repositioned to the right spot and chocked I asked the ramp manager what happened and inquired if the was anyone injured or hurt and if there was any damage to the plane. He assured everything was okay and since it was an international flight I couldn't leave the airplane to go on the ramp a see for myself and talk face to face the ramp manager to see how this happened. As a crew we evaluated that there was no damage or injuries so left the aircraft. I suggest better ramp training.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.