What was found
LAN - AFTER LIFTOFF, THE CREW ELECTED AN AIR TURN BACK WHEN THE GEAR WOULD NOT RETRACT. THEY REPORTED THAT THE MOTOR RUNS AND POPS CIRCUIT BREAKER. AFTER AN UNEVENTFUL LANDING, MAINTENANCE REPLACED THE HYDRAULIC POWER PACK AND MOTOR P/N 571302. ALL TESTS WERE SATISFACTORY.