AES op, not AEC op. Airborne Electronic Sensor Operator (AES OP). (boy I hope I didn't get that wrong)
To answer your question about AECs flying, as far as I have learned, only Air Weapons Controllers have the opportunity to fly on AWACS. Canada doesn't have any so it would be with the Americans or with NATO(not sure if those are the only two opportunities).
Here is an awesome website about the postings and jobs available to AECs