Complex sentence: On 27 December 1991, ice had collected on the wings' inner roots (close to the fuselage) before takeoff, which broke off and was blown/sucked into the engines as the aircraft became airborne on takeoff.
Split into simpler sentences: On 27 December 1991, ice had collected on the wings' inner roots (close to the fuselage) before takeoff. It broke off and was blown/sucked into the engines as the aircraft became airborne on takeoff.