Complex sentence: The Boeing Vertol CH-113 Labrador was the Canadian name for the CH-46 Sea Knight and was a twin-engine, twin-rotor, Canadian search and rescue (SAR) helicopter used in air-marine rescue operations from 1962 until 2004.
Split into simpler sentences: The Boeing Vertol CH-113 Labrador was the Canadian version of the US CH-46 Sea Knight. It was a twin-engine, twin-rotor, helicopter used in search and rescue operations from 1963 until 2004.