Lyle was fascinated by aircraft and joined the RAF aged seventeen and a half. One of his first assignments was Singapore which was a long way for someone who had never travelled further south than Liverpool. In 1978 he was posted to the Nuclear Strike Force in West Germany, but further information on this is classified and he could not give details.

He really enjoyed working with the Chinook helicopter and when the Falklands war began his squadron was assigned to the invasion fleet. On their journey through the Atlantic the RAF troops trained with the Army and a RSM informed the troops that some of them may not be coming home. It was then that he suddenly realised that they were really going to fight in a war. The paratroopers were psyched up before they landed, which affected the RAF personnel too. Lyle watched an Argentine plane bomb British positions which reinforced the feeling that this was a real conflict. After the first landings Lyle, carrying a large bag of cryptographic material, and nineteen others were put ashore temporarily on a hillside. They stayed there for four days and nights, with only sidearms and little food. It was cold, wet and windy but eventually they were brought back. His squadron lost all their aircraft but no personnel were killed. After this the men of the squadron were split up to help on board the invasion fleet. Lyle had an exciting time in the RAF and enjoyed his career.