The pilot reported that, after departure, he noticed the Cessna 310’s landing gear did not retract as usual. He began to troubleshoot the problem and actuated the gear-down lever.
The landing gear did not extend, and the green landing gear light in the cockpit did not illuminate.
He recycled the landing gear, but the gear still did not extend.
He continued to the airport in San Antonio, Texas, and asked an air traffic controller to observe the position of the landing gear. The controller reported that the gear appeared to be down and cleared the flight to land.
During the end of the landing roll, the left landing gear retracted, which resulted in substantial damage to the left wing spar.
Post-accident examination of the airplane revealed that the landing gear compartment was dirty and covered in oil and debris. However, the examination did not reveal the reason for the landing gear retraction.
The NTSB determined the probable cause as the retraction of the left main landing gear after landing for reasons that could not be determined.
NTSB Identification: CEN15LA089
This December 2014 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
At the factory upon 1st flight the landing gear was extended manually. During pre-flight the gear might be operated several times with battery/APU for set up checks and gear door rigging. But here again it was a new airplane. The type of gear used on their fleet before the age of hydraulics was added, models(310/320/335/340’s never benefited from this change) the gear required regular service and inspections. Infrequent operations also adds it’s own troubles. bearings get stiff from dried out lubricants as well. Jack the aircraft, cycle the gear several times each annual both electrically and by crank. Check the tensions and spring loads of the down locks before giving it back to the owner. Better yet to get the owner to assist and learn about what equipment he/she is operating. Mr. Wallace told my supervisor that the 310 was never meant to be built for 25 years (55-81). Some 5250 aircraft were built during that period. Duane flew the last one built at the factory after he retired.
A dirty landing gear is indicative of sloppy or poor maintenance. Microswitches on the landing gear illuminate to indicate gear up and locked or down and locked with the actuator over center.
The owner was saving a few dollars on maintenance. The pilot was inattentive during pre-flight inspection.
Whoever did the last annual inspection did not do a competent job. An annual should have teh plane on jacks and the gear cycled under power and by the emergency extension.
The time it takes for the gear to cycle is a measurement of the condition of the gear motor and the lubrication and condition of the various bushings.
The airplane fleet is now an antique and extra maintenance is required that includes cleaning and lubrication.
The only good thing is that inadvertent gear retraction or gear up landings are rarely fatal.
http://langleyflyingschool.com/PDF%20Documents/Pilot%20Operating%20Handbooks/Cessna%20152/Section%208%20Aircraft%20Handling,%20Service%20and%20Maintenance.pdf