As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CIU - CREW REPORTED, THE LANDING GEAR FAILED TO EXTEND WHEN SELECTED DOWN. A MANUAL GEAR EXTENTION WAS PERFORMED AND AN UNEVENTFUL LANDING WAS MADE. MX REMOVED AND REPLACED SERVICE VALVE BECAUSE OF AN INTERMITTENT MICROSWITCH. OPS CHECK WAS GOOD. (M)