As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR FAILED TO EXTEND WHEN SELECTED. GEAR WAS PUMPED DOWN AND AIRCRAFT LANDED WITHOUT INCIDENT. INVESTIGATION REVEALED THAT THE C-CLIP ON THE HYDRAULIC POWERPACK COUPLING WAS MISSING AND ALLOWED THE COUPLING TO MIGRATE ON THE SHAFT UNTIL IT NO LONGER CONNECTED THE MOTOR TO THE PUMP.