In a far corner of the room, Dave Brock, 60, has two tasks on the go. He is making an engine bearer – the frame the Merlin rests on – for one of the planes they are restoring, alternating between working on that and restoring a Hurricane fuel tank which has been damaged. Like Hurst, Brock worked in the commercial sector before moving over. “I wanted to work in restoration for years, but I never had the opportunity,” he says. “I love the variety of the work and the freedom you have to make things.” Working on these aircraft has given him renewed appreciation for the men who built and flew them in the 1940s. 

“It was all done with a ruler and a pencil. It’s not like now when you just chuck it into a computer. Someone sat down and designed it, with all the stresses and the loading. These planes have soul,” he adds. “I went up in one, and it wasn’t so much the flying, but the thought that there was an 18-year-old kid up the front, with about four hours experience, going to shoot down Germans.” 

Once complete, some are kept, others sold to collectors and enthusiasts. It is not a cheap hobby. A fully restored Spitfire can cost up to £3 million, plus £40,000-£50,000 per year in insurance, with maintenance costs on top of that. An annual inspection could be another £50,000. One of the owners keeps his plane at Biggin Hill like others might keep a classic car, popping over to fly it down to Goodwood, perhaps, or hop over the Channel. While the RAF have more discretion over how they treat their planes, the Spitfires restored for everyday use must adhere to stringent Civil Aviation Authority regulations. 

If Brock is in a later part of his career, his colleague Simon Groves, 19, is just starting out. He has been at Biggin Hill for two and a half years, having originally come on work experience.