Mr Smyth died at his Shrewsbury home, where he still lived independently, on October 26.
He was one of the last survivors of "The Few" - the pilots who defended Britain against the might of the Luftwaffe when the nation stood alone in 1940.
A widower, he leaves daughters Daphne Lewis and Hilary Joy, four grandchildren, and eight great-grandchildren.
Funeral arrangements will be announced later.
Flight Lieutenant Smyth fought as a 19-year-old in the closing stages of the Battle of Britain and later in the war was awarded the Distinguished Flying Cross for his work in a photo reconnaissance Spitfire.
He also ferried communications between London and Winston Churchill at Biarritz and Clement Attlee in Berlin for the Potsdam Conference in 1945.
Although reluctant to talk about his experiences, he shed some light on his wartime exploits in a 2012 interview.
Born near Croydon airport, he was fascinated by the comings and goings of the Imperial Airways flights, and with war clouds gathering, applied to join the RAF Volunteer Reserve.
He did his training in Tiger Moths and Hawker Hart biplanes, finishing around August 1, 1940, when the Battle of Britain was in full swing.
Initially he converted onto twin-engined Blenheims, but volunteered to go onto single-seat fighters and within two days joined 111 Squadron at Debden.
He was to recall: “111 Squadron had Hurricanes. The CO there was rather shattered when I arrived at Debden and had never flown a Hurricane. I had to go on a Hurricane course.”
By the time the then Sergeant Smyth rejoined his squadron in the climactic period of the Battle of Britain in September 1940, it was at Drem in Scotland, recovering from its losses, reforming and gaining new pilots.
But at the end of September he was pitched into the heart of the Battle of Britain, being posted to join another Hurricane squadron - 249 - at North Weald.
“We saw a bit of action from there, being in London, mainly pursuing bombers. I was 19.
“I helped shoot two or three down. There was a 109, and a Heinkel 59, and something else. Other people claimed them as well. You will often find that two or three people claimed the same aircraft.”
There were however no feelings of triumph. “I don’t like shooting people," he said.
“At the so-called end of the battle at the end of October, what I remember best was Armistice Day. I flew over London at 11 o’clock on November 11.
"I looked down on London and thought here we are, 20 years after the Armistice, trying to defend our capital. Where do we go from here? At the time people had no idea what future they might have. Every day might be their last. That applied to civilians on the ground just as much.”
With the Battle of Britain over, he then flew with 615 squadron, where he recalled there were seven Free French pilots, three Poles, two Czechs, and a South African, as well as British. Later he became a flying instructor, and then was teaching people how to fly gliders.
“In spring 1943 I packed up that and I volunteered to do a second tour of operations.”
Now he was at RAF Benson flying unarmed photo reconnaissance Spitfire XIs and XIXs.
“I flew all over Europe - France, the Low Countries, Germany,” he said. “I went to Berlin once.
“Quite a lot of it was looking at the bombing and looking out for flying bomb sites and rocket sites, other times looking at ports and mysterious places on the ground that the intelligence people wanted to check up on. I was usually flying at about 27,000 to 30,000ft.
“It was nice being alone and high up and nobody else in sight.”
It was during this period that he won his DFC, and also had his closest shave, when his path crossed that of an armada of Flying Fortress bombers.
“Their Mustang escorts saw me and luckily I saw them in time. They were firing at me. I just took evasive action.”
Leaving the RAF in January 1946 with the rank of Flight Lieutenant, he was not to fly again until about 1980, when he flew on a holiday jet, and by special arrangement was allowed onto the flight deck.
“I felt very much at home looking down on the Mediterranean from 30,000ft.”