Complex sentence: The cruising speed of a Boeing 747 is 481 knots, the airspeed indicator was shown in a previous scene to be over 300 knots, while the maximum speed of a Sikorsky MH-53 Pave Low helicopter is 170 knots.
Split into simpler sentences: The cruising speed of a Boeing 747 is 481 knots and the airspeed indicator was shown in a previous scene as reading over 300 knots. The maximum speed of a Sikorsky MH-53 Pave Low helicopter is 170 knots.