Experts in Shropshire have begun the delicate task of cleaning barnacles and silt from a rare German Second World War Dornier 17 bomber which has been at the bottom of the sea for more than 70 years.
Conservation staff at the RAF Museum in Cosford are using a very dilute acid to clean away the debris that has stuck to the aircraft.
The remains of the largely-intact bomber were lifted from the bottom of the English Channel where it has lain since being shot down in the Battle of Britain.
In what is believed to be one of the largest recoveries of its kind in British waters, the aircraft was brought ashore and transported to the museum in Shropshire more than 200 miles away.
The Dornier, including the main fuselage, the wings and both propellers, is now inside two specially-built polytunnels being treated with a special cleaning solution.
Darren Priday, deputy manager of conservation at the museum, explained that the process of getting the aircraft ready for full public display could take at least 18 months.
"There's no example of a Dornier 17 as complete as this one anywhere," he said.
"Now the parts are in the polytunnel, they are being sprayed with an irrigation system.
"It's citric acid, pH-balanced in water, and the idea is that will remove the impurities from the salt water and also the crustaceans that are on the airframe at the moment."
The public can see exactly how the conservation work is progressing as the exhibit is open to visitors.
The bomber, 1,500 of which were built, was discovered by divers in 2008.
Sonar scans by the RAF Museum, Wessex Archaeology and the Port of London Authority confirmed the identity of the aircraft as the Dornier Do 17Zv Werke number 1160.
The twin-engine, twin-fin configuration - together with the narrow fuselage and shoulder-mounted engines - gave the aircraft a distinctive silhouette and earned it the nickname "the Flying Pencil".
Mr Priday said circumstances had combined to help preserve large parts of the aircraft as it lay at Goodwin Sands at a depth of 50ft (15m).
He said some of the crew's water bottles stayed pressurised despite the length of time under water, while the tyres of the undercarriage appear to be inflated.
"I think the barnacles have done something (to preserve the aircraft) but also some parts have been underneath the sand," said Mr Priday.
"Some areas have deteriorated badly but the natural products, like your rubbers and leathers, have survived quite well."
He said it could take "between 18 months and two years" to complete conservation and it had not yet been decided how the aircraft would be displayed, although it will be moved to the RAF Museum in London once this phase of the project has been finished.
Mr Priday added: "Once we've removed all the impurities, we will look at whether we can spray on some sort of polymer or lacquer to keep the air away from the base metal."