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Thai A340 Blown Tires At MEL (Part 2)

Thu Dec 08, 2005 3:04 pm

Preliminary Report for the incident has been published.

The data revealed that the wind direction during the landing approach from 850 ft RALT was about 250 degrees T, allowing for some minor variations. Wind speed from between 850 ft and 400 ft RALT was about 22 kts, with a maximum 27 kts occurring at 500 ft RALT. From 400 ft RALT, the wind speed reduced to about 18 kts. About 6 seconds before touchdown, the wind speed began to increase, and reached a peak of 40 kts about a 1⁄2 second before the right MLG parameter transitioned from AIR to GROUND.

The aircraft’s heading remained relatively constant between 166 and 168 degrees M from 850 ft RALT, then increased to 175 degrees M, coincident with the wind gust encountered just before touchdown. The aircraft touched down with 15 degrees right yaw (‘crab’), on a heading of 175 degrees M, and rolled in a 5-degree right wing low attitude.

The right MLG parameter was the first to transition from AIR to GROUND at touchdown, followed by the left MLG, then the centre MLG. The centre MLG parameter then transitioned back from GROUND to AIR, followed by the right MLG, indicating a ‘bounced’ landing. The right MLG parameter transitioned back to GROUND 1⁄2 second later. The left MLG parameter remained in the GROUND parameter after the initial touchdown.

Touchdown vertical 'g' loading was about 1.6 'g', and lateral 'g' loading was about 0.4 'g' to the left, indicating that the aircraft was in a right sideslip.

IMHO the wind speed increase is a key factor. Maximum crosswind limit for the 340-600 is 37 kt including gusts.

Not exactly the sort of conditions you would let an FO with 43 hrs total time on type to perform.
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