Incident History
On 26 May 2009 at 08:56 UTC, a Cessna 180K, registration D-EGSW, operated by AERO VIP, was conducting a local visual flight rules flight for transporting parachutists from Portimão Aerodrome (LPPM). During the initial take-off roll on runway 11, after traveling approximately 110 meters, the aircraft swerved suddenly to the left. The pilot attempted to correct to the right while sensing abnormal behavior from the left landing gear. The aircraft turned 180 degrees on the runway and continued moving until it came to rest heading 280°, with the propeller and left wing tip striking the asphalt. The left main landing gear leg separated from the aircraft. The pilot and four passengers were not injured.
Aircraft and Crew
The aircraft was a Cessna 180K single-engine high-wing monoplane (serial number 180-52975, manufactured 1978). Its maximum take-off mass was 1270 kg and empty weight 802 kg. The 58-year-old male pilot held a valid CPL(A) license issued by INAC, with total flight experience of 4351:00 hours, including 23:00 hours on type.
Damage and Investigation
The aircraft sustained damage to the propeller blades, the left main landing gear leg, and the left wing tip. Inspection revealed that the retaining nut on the left main landing gear attaching bolt was missing. The bolt was found bent with damaged threads. The Cessna parts catalog specifies bolt AN7-20A (no hole) and self-locking steel nut AN365-720C; however, the installed bolt had a hole and the installed nut had a golden color and was not self-locking. The serial numbers of the installed bolt and nut could not be identified. The bolt's bending indicated it was subjected to a side load.
Probable Cause
The collapse of the left main landing gear was due to the failure of the bolt that holds the landing gear leg to the aircraft.