Complex sentence: The only other person on the helicopter who can land a 747 is Captain Murdock, who is tethered to the rear of the helicopter and lowered to the jet and successfully enters it through the hole in the cockpit.
Split into simpler sentences: The only other person on the helicopter who can land a 747 is Captain Murdock. He is tethered to the rear of the helicopter, lowered to the jet and successfully enters it through the hole in the cockpit.