A McDonnell Douglas MD-11 freighter was operating a charter freight flight from Miami International Airport (Florida, USA) to Campinas-Viracopos, Sã0 Paulo (Brasil) on this day in 2012. The crew consisted of two pilots and a mechanic, the co-pilot was the Pilot Flying and the captain was the Pilot Monitoring.
The failed and collapsed left main landing gear under the wing (Source: baaa-acro.com © unknown) After an uneventful flight, ATC cleared the aircraft for an ILS Approach to runway 15 at Viracopos airport. 15 minutes before landing the crew received the ATIS (Automatic Terminal Information Service with the following weather details;
Wind: 150º at 20 kts, gusting 29
Visibility: > 10 km
Clouds: Broken, ceiling 9000 feet
QNH: 1020 hPa
When the aircraft was on final approach, Viracopos Tower Control reported the wind was 150º at 19 knots, when the landing clearance was issued the wind was 140º at 20 knots, gusting to 29 knots. The aircraft was properly configured for the landing and with a landing weight of 434.000 lbs (197.036 kg), the Landing Reference speed was 165 knots ( taking into account a wind correction), which was maintained during the approach.
The damaged engine when the aircraft was recovered (Source: baaa-acro.com © unknown)
At a height of 50 ft the PF started to pull the power levers back, flaring the aircraft. The aircraft touched down with a sink rate of 10 feet/second and a pitch of 5.5 degrees, at which time the left main landing gear collapsed. Th aircraft skidded down the runway for ~800 meters before coming to a stop. Airport Fire and Rescue Services were alerted and applied FFF (Fire Fighting Foam) to prevent a fire from breaking out. The crew evacuated the aircraft without injury. Damage to the aircraft was substantial, the following damage was found;
Left Main Landing Gear
Body Gear Tire
The incident was reported to the Aeronautical Accident Investigation and Prevention System (SIPAER) which launched an investigation into the accident. During the investigation, it became apparent the aircraft suffered a hard landing at Montevideo (Uruguay) on the 20th of October 2009, which caused the failure of the right-hand main The aircraft in Montevideo (source; SIPAER) landing gear.
An investigation into the failure of the landing gear leg was carried out by investigators and by Boeing. The conclusion of this investigation was that in one of the points of origin of the failure, the analysis had identified characteristics similar to a seemingly previous point of fracture, which was likely to have resulted from a previous overload. According to the technical report, it was not possible to affirm that this was the reason for the collapse, but the possibility should be considered.
Detail picture of the fracture (©SIPAER)
The cause of the accident was that;
"The landing gear failed due to overload in the cylinder structure”. The fracture started in the rear section of the cylinder in a connection hole which served as a tension concentration point and ended in the front part of the cylinder with its breakage into two parts. "
The full investigation report on this accident, which served as the source for this blog, is available for the readers' reference by clicking on the .pdf file below;
Recovery work progressing (Source: baaa-acro.com © unknown)