Accident Sequence
After receiving clearance to land, the pilot extended the landing gear and set the flaps to full. He observed three green landing gear indication lights. During the landing flare, he applied slight engine power. The airplane landed normally but then rocked slightly side to side. When the full weight of the airplane was on the main landing gear, the left main landing gear collapsed, followed by the right main landing gear and the nose gear. The airplane slid approximately 400 to 500 feet on the runway before stopping.
Pilot Report and Maintenance History
The pilot reported no prior problems with the landing gear. A recent landing gear inspection had been conducted due to previous slow extension, retraction, and noise. The slow operation and noise were corrected by lubrication, and the landing gear returned to normal after three or four flights.
Postaccident Examination and Repairs
A mechanic performed postaccident maintenance, installing new Brace Assemblies (part numbers 38-815125-12 and 38-815125-14). After installation, retraction tests functioned normally. While moving the airplane with a tug, the mechanic noticed that the right landing gear was about to fold again. Examination revealed that the down lock mechanism had not pulled into place. A pulley, part number MS20219-2, was split on one side, allowing the cable to run into the split and causing the downlock cable to fall short of engagement. The pulleys had to be removed to see the split. The same condition was found on the left side. Both pulleys and both downlock cables were replaced, which resolved the landing gear downlock problems.
Logbook Records
The airplane's logbook records showed it received a 100-hour and annual inspection on July 31, 2004, approximately 70 flight hours before the accident. During that inspection, the mechanic performed a main landing gear retraction and emergency extension test.