In the early 1960s, the Royal Marines and the British Army required a vehicle that could be carried by air by their Westland Wessex helicopters that had a maximum load capacity of 1,134kg (2,500lbs).
In order to make their vehicles compatible, Land Rover began to work on a lighter version of their Series IIA by making the body and other components detachable so that the overall base weight was in-range of the helicopters load carrying capacity.
The result was the Land Rover Half-ton, also known as the Lightweight or Airportable. The tilt roof, upper body parts, doors and windscreen were removed while the width was reduced by 4 inches (100mm).
Complete, the Lightweight Land Rover Series IIA’s weighed in at 1,202kg (2,650) which made them light enough to be lifted by the helicopters of the time.