Complex sentence: Watson attempted to retract the landing gear to arrest the slide but this failed and the aircraft slipped backwards off the container and onto the roof of a van parked on the deck which partially held up the fuselage and stopped a further slide.
Split into simpler sentences: Watson attempted to retract the landing gear to arrest the slide but this failed and the aircraft slipped backwards off the container and onto the roof of a van parked on the deck. The van partially held up the fuselage and stopped a further slide.