As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3626 (MSP TO SDF) CREW PERFORMED AN AIR RETURN FOR A GEAR DISAGREE WARNING (PASSING 11300FT) IN THE CLIMB, WHILE INCREASING SPEED TO 290 KTS. LEFT MAIN GEAR SHOWED UNSAFE. THE AIRCRAFT LANDED SAFELY BACK IN MSP. COMPLIED WITH PA 05-018J AND ADJUSTED LEFT MAIN LANDING GEAR DOWNLOCK NR 2 SENSOR(PS10GA) IAW AMM 32-61-05. NUMEROUS GEAR SWINGS COMPLETED WITH NO MESSAGES INDICATING.