As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TRAINING LT AND RT MAIN LANDING GEAR WILL NOT RETRACT WHEN HANDLE IS SELECTED IN THE UP POSITION. MAINTENANCE REPLACED BRAKE SELECTOR VALVE. IAW AVRO AMM 32-41-91. OPS & LEAK CHECK GOOD. PERFORMED REQUIRED GEAR SWINGS PER AMM 32-20-00.