History of the Flight
The flight conducted a normal approach to Runway 26 at Elstree Aerodrome. The wind was from 330 degrees at 6 knots. All three landing gear indicator lights showed green, indicating down and locked. At approximately two miles from touchdown, the pilot selected full flaps, which was visually confirmed. The landing was smooth, but during the landing roll the 'Gear Unsafe' warning horn activated. The pilot observed that the left main landing gear green indicator had extinguished and the red 'Gear Unsafe' light had illuminated. The right main and nose gear lights remained green. Shortly thereafter, the left main landing gear collapsed, causing the aircraft to veer to the left and come to rest on the grass adjacent to the runway. The pilot performed emergency shutdown procedures, and both occupants vacated the aircraft without injury.
Examination and Findings
A metallurgical examination of the left landing gear components revealed that all failures resulted from a single overload event. There was no evidence of fatigue cracking, corrosion, or manufacturing defects in the failed parts.
Pilot's Assessment
The pilot, who was also the aircraft owner, proposed that the landing gear collapse may have been caused by the left main gear being slightly out of rig. This misadjustment could have allowed the side brace to unlock when the aircraft ran over a bump on the runway, leading to the gear collapsing.
Aircraft Information
The accident involved a 1973 Cessna 310, registration N310QQ, powered by two Continental IO-470-V0 piston engines. The flight was private, with one pilot and one passenger onboard. The pilot held a Commercial Pilot's Licence and had 875 total flight hours, including 334 hours on type. The aircraft sustained damage to its left side and left main landing gear.