As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE FLIGHT CREW EXPERIENCED POWER SURGES ON BOTH ENGINES ON TAKEOFF AND CLIMB. BLEED AIR WAS SELECTED OFF AND THE AIRCRAFT RETURNED FOR LANDING. MAINTENANCE INVESTIGATION REVEALED THAT THE AIR CONDITIONING BLEED AIR SWITCHESAND LINES HAD BEENCONTAMINATED WITH WATER CAUSING THE SWITCHES TO FREEZE. THE SWITCHES WERE REMOVED, CLEANED AND REINSTALLED.