A spokesperson said they were “extremely saddened” to learn overnight of the passing of Mr Johnson.
They said: “Johnny was recognised as being the last of the Dambusters, but he was so much more than that.
"He was a man who cherished his loving family, and our immediate thoughts and sympathies are with them today.”
They went on: "Johnny was a very dear friend of the Battle of Britain Memorial Flight and visited us on many occasions, most notably when he came to us in 2018 and we were delighted to be able to fly him in the Lancaster for the last time.
"Johnny was an advocate for his colleagues from 617 Squadron, and the wider Royal Air Force in World War Two. He will be remembered for passionately guarding their reputation.
“He was a truly inspirational man; we will miss him dearly.
“Lest We Forget.”
Johnny, who was born in the county, was the last surviving original member of the Dambusters, members of the RAF's 617 Squadron who were assembled to bomb three dams in Germany's Ruhr Valley on the night of May 16-17 1943 – also known as Operation Chastise.
And this year marks 80 years since the risky raid, in which the revolutionary bouncing bomb, the brainchild of engineer Barnes Wallis, was dropped at low level on Germany’s industrial heartland in the Ruhr Valley.