The son Edward Henderson and Stella (Fraser) Johnstone, Edward Grahame Johnstone joined the Royal Naval Air Service on 6 May 1917. After training with 12 Naval Squadron, he was posted to 8 Naval Squadron where he scored 17 victories flying the Sopwith Camel.
Distinguished Service Cross (DSC)
Flt. Sub-Lieut. Edward Grahame Johnstone, R.N.A.S.
For the pluck and determination shown by him in engaging enemy aircraft.
On the 19th January, 1918, he attacked five Albatross scouts, and engaged one, nose on, opening fire at 75 yards range. The enemy aircraft turned on its side and spun. He followed, and engaged again at 30 yards range. The enemy aircraft went down completely out of control Later in the day, in a general engagement with fourteen Albatross scouts, he followed one down to 8,000 feet, firing all the time. This is confirmed by other pilots of the patrol to have fallen completely out of control.
On several other occasions he has destroyed enemy machines or brought them down completely out of control.