Airfield site
A large part of the Ness was acquired by the War Department in 1913. Between August 1913 and the summer of 1916 this site was drained and levelled to form airfields to the left and right of the road.

There followed perhaps the most significant turning point in the history of the Ness with the arrival of part of the Central Flying School's Experimental Flying Section from Upavon in Wiltshire. This event was the start of a 70 year period of intense military experimentation, which as well as leaving a variety of physical traces, has given the place what has been described as 'the mystique of secrecy'.

The longevity as a place of military experimentation is significant. The arrival of the military curtailed the traditional uses of the Ness by the local population, however, the station soon became an important source of employment for them. Most of the experimental work related to aerial warfare.

Significant advances were made in both military hardware and experimental techniques and equipment. Amongst the pioneering work of the First World War were early experiments on the parachute, on aerial photography and on bomb and machine gun sights as well as evaluation of aircraft and the development of camouflage.

After the War, Orford Ness was put on a 'care and maintenance' order until 1924 when it was reopened as a satellite of the Aeroplane and Armaments Experimental Establishment at nearby Martlesham Heath. The Ness was used as the firing and bombing range. From 1939 to 1945, this site was covered in concrete anti-glider defences.