The Units are sealed and designed to durable for service, They only need to be charged and plugged in for sync with online system when aircraft are returned to base.
Each aircraft will have 2 x units: 1 in-flight.. and 1 on the ground charging and syncing. And be swapped over each time airplane returns to base.
Spare units will need to be available to replace faulty ones if any and the faulty ones returned to us for repair.