A wireless communications system and method for use with aircraft includes an airline network and an aircraft communications system. In a disc drive designated to read and write long sequential records, the track misregistration budget is reduced to account for previously written tracks not being encroached on one side. The circuit is able to transition quickly and make fast adaptations to new levels of the input signal by use of a restart mechanism used to dynamically modify the gain of the loop filter thus enabling the AGC circuit to quickly adapt to changes in the signal level of the input.