 They applied full power to this engine, which caused the craft to enter a circling descent until crashing into trees; at the time of impact it had almost no forward velocity.Five trees were driven through the fuselage, yet their trunks remained intact.The crash was attributed to the fact that, as per airline policy, the pilots had delayed arming the engine ice protection systems even though they were flying in icy conditions; this caused the engines to lose too much power.