LONDON (AP) — Gilbert Clarke leans back on the seat of his mobility scooter, cranes his neck and gazes into the bright blue skies over East London, remembering the moment 80 years ago when he knew the invasion of France was under way.

Clarke, then an 18-year-old Royal Air Force volunteer from Jamaica, was still a trainee learning about the intricacies of radar systems when the roar of aircraft engines forced him to look to the heavens on June 6, 1944.

“You couldn’t have seen the blue sky,” Clarke recalled, his voice tinged with awe eight decades later. “Was all planes. Hundreds and thousands of them — all shapes and sizes. All different type of plane. The instructor (said) ‘Hmm. Well, boys, it’s started.’’’

“We all shouted, `Give them hell,’ or probably something a lot stronger than that.’’

Clarke got to make his own contribution after he finished his training a few weeks later and was posted to a series of air bases where he serviced the radio and radar systems of British and American aircraft for the rest of the war. He plans to travel to northern France later this wee k, joining other veterans of the Battle of Normandy for ceremonies marking the 80th anniversary of the D-Day landings that started the campaign to liberate Europe from Nazi rule.