A320
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 270; Flight Crew Total 19000; Flight Crew Type 9000
Situational Awareness
Ground Event / Encounter Other / Unknown
Flight Crew Became Reoriented
Airport; Weather; Human Factors
We taxied into gate during cold weather ops. All airport surfaces were covered in snow with braking action good to fair. After receiving the chock signal from the guide man; I released the parking brake due to hot brakes and a quick turn. I went heads down to complete the parking checklist and noticed the aircraft had started moving backwards. I reset the brakes and looked for the guide man who was looking at the nose wheel but gave me no signal to reset the brakes. Another ramp person emerged from under the nose and gave me the set parking brake signal. I spoke with a ramp supervisor. He stated that the chocks were not strong enough to hold the aircraft due to ice under the snow. From the tire and shock drag marks in the snow I estimated about two feet of rearward movement from the original stop mark. I'm not sure how much movement occurred after I reset the parking brake. Luckily the belt loaders had not yet pulled up to the aircraft. This was a new and unexpected experience for me and I could not find any reference or warnings for this type of occurrence in the cold weather ops section of the flight manual.
A320 Captain experiences aircraft movement at the gate after being choked and releasing the brakes on an icy ramp.