Russian investigators have concluded that an unstable approach at high speed contributed to the fatal Red Wings Tupolev Tu-204 overrun at Moscow.

The aircraft’s approach speed, up to 24kt higher than it ought to have been, prolonged the Tu-204’s float before it made contact with the runway.

This resulted in a reduction in available landing distance, while the soft 1.12g touchdown in a crosswind meant weight-on-wheels switches did not activate, and the spoilers did not deploy.

This also meant the thrust-reverse system could not deploy, owing to safety logic which prevents activation while the aircraft is airborne. However, the crew did not wait for confirmation of reverser deployment before engaging high engine power, which instead accelerated the Tu-204 forwards.

Russia’s Interstate Aviation Committee, in its final report into the 29 December 2012 accident, says the crew’s failure to engage reverse thrust correctly meant the aircraft did not decelerate and eventually overran, colliding with a highway embankment.

The crew demonstrated poor resource management which allowed the approach to become unstable, the inquiry states, adding that an inadequate level of flight operations monitoring meant such deficiencies went undetected.

Despite another serious landing incident involving a Red Wings Tu-204 at Novosibirsk nine days earlier, which also related to weight-on-wheels switches, the inquiry says no “timely preventative measures” were taken.

Five of the eight occupants of the aircraft, which had been operating a positioning flight, were killed in the crash.

Source: Cirium Dashboard