Background
The aircraft, a Cessna 404 Titan registered PT-WQT, was manufactured in 1977 and powered by two Continental Motors GT SIO520M piston engines. It was operated by a Brazilian survey company as part of a survey programme over the Falkland Islands. The flight crew consisted of a commander (41 years old, holding a Brazilian Commercial Pilot's Licence with 4,924 total hours, including 305 on type) and a systems operator. The commander had 70 hours of experience in the Falkland Islands over 17 flights, with 23 hours as pilot-in-command.
History of the Flight
Earlier on 29 May 2004, the same crew had completed a 2-hour 45-minute survey flight from Stanley Airport. After a 35-minute ground break, during which the commander inspected the aircraft and supervised refuelling, the aircraft departed at 1630 UTC (1230 local) for a second survey flight over West Falkland. The crew comprised the commander and the systems operator; the commander had acted as co-pilot on the previous flight.
About 2 hours 30 minutes later, 10 minutes before landing, the commander contacted the control tower and received weather information, including snow showers moving north-west. Wind conditions were reported as 200° at 20 knots, gusting to 28 knots. He joined the left-hand circuit for Runway 27, receiving further wind readings: 190°/20–25 knots and 200°/20–25 knots. He reduced speed abeam the threshold to 120 knots, selected approach flap, and lowered the landing gear. On finals, with the approach stabilised, he selected landing flap and maintained runway alignment in the strong crosswind with left wing lowered and right rudder pedal.
Accident Sequence
The commander recalled crossing the threshold in a normal, stabilised attitude at 105 knots. At touchdown, the left main wheel contacted first, followed by the right main wheel and nose wheel. The commander maintained aileron control left to keep load on the left wheel. With the aircraft fully on the runway, he released back pressure on the elevator and brought the power levers to idle. He then noticed the nose turning right. He attempted a small correction with left pedal but the aircraft did not respond. A shock was felt in the right pedal, and the aircraft began to turn left. He tried to maintain alignment with normal pedal movements but needed greater amplitude. With the nose gear not responding to steering inputs and the aircraft slowing, he applied brakes. He felt the nose go down and pulled the control yoke back, but there was not enough time to shut down the engines to prevent the propellers from striking the ground while rotating. The aircraft came to a halt near the runway centreline. Both crew exited safely.
From the control tower, the landing appeared successful, but the aircraft swerved slightly and the nose landing gear collapsed at about 40 knots. The aircraft then slid down the runway in a straight line on its nose and main wheels. The Airport Fire Service reported no apparent injuries, no fire risk, and no fuel spill.
Examination
Post-accident examination confirmed structural failure of the forward attachments of the nose landing gear, consistent with overload conditions rather than pre-existing damage. All six propeller blades were damaged by contact with the runway while rotating, and the flaps were in the fully extended landing position.
Runway marks matched the accounts from the crew and eyewitnesses. Rubber marks from the nosewheel tyre began 180 metres from the threshold of Runway 27; propeller strike marks started 8 metres further on. Surface abrasions from metal components around the nose leg continued, and the aircraft stopped 306 metres from the threshold.
Weather
Witness accounts consistently indicated a substantial crosswind from 200° at 20 knots, gusting between 25 and 28 knots. At 1840 UTC (1440 local), cloud was broken at 2,000 feet, visibility was 25 km, barometric pressure was rising, and surface temperature was +1°C. Some witnesses, including the commander, described patches of snow and ice on the runway. Photographs taken shortly after the accident showed small patches of ice and areas with a light covering of blown snow.
Analysis
The landing was performed with a crosswind component of between 16 and 19 knots. The commander later commented that the runway condition may have played a part in the initial nose swing, which he attempted to correct without immediate effect. This would have led him to apply more pedal movement, deflecting both the rudder and the nosewheel. If the nosewheel, in a deflected position with low adhesion due to ice, then encountered a dry, rough section of the runway, the tyre deflection would have caused substantial loads on the nose leg structure, additional to those from the crosswind. The investigation considered this a reasonable explanation for the structural failure of the nose leg.