Max R8
The bridge Ray Hanna flew under when filming Piece of Cake in 1988 was Winston Bridge in Co. Durham.
They chose it because it's not on a busy road or too close to houses and has a straight run-in for the Spitfire. I think, from memory, he flew it at about 200 kts.
This pic of the bridge gives only an idea.
The picture with the Spit flying under is spectacular, but I can't find my copy to scan and post here.
Hunter through Tower Bridge 1968
No personal knowledge about this one, but a quick google came up with ....
"In 1968 it was the RAF's 50th birthday, yet the top brass did not se fit to mark this with any flypast, choosing instead for mere parades on the ground. Many RAF personnel were less than impressed and one Flt Lt Alan Pollock of 1(F) Squadron decided to mark the occasion in style - first with toilet-roll bombing missions against rival squadrons, and then on April 5th, while suffering from the beginnings of pneumonia which no doubt had some affect on his decision making processes, he flew his Hunter over London and at the last second decided to fly under the top span of Tower Bridge! Knowing of the consequences of his unauthorised trip, he proceeded to beat up several airfields and landed to meet his fate. It would be the end of his RAF career (he went on to run a successful exporting company), with political influences making sure he was treated incredibly unfairly - thrown out of the RAF with no right to appeal, no court martial at which he could present his case, medical evidence ignored, unable to meet with his superiors, etc.
It took until 1982 for his case to be fully heard, and only then was he exonerated."