MOSCOW - Russian experts probing the weekend plane crash outside Moscow which killed 71 people said the accident may have been caused by ice on speed probes which led to faulty information on the craft's airspeed. "A factor in the development of a special situation in the flight could be the wrong data about flight speed on pilots' indicators which was likely due to iced pitot tubes (speed probes) while their heating systems were shut off," said the Russian Interstate Aviation Committee (IAC) which investigates aircraft incidents.