Very impressive
A while ago I read that a couple of Spitfires that are flying today, had the wing spar in each side renewed. These were a special custom made RHS (or HHS for over here) rectangle section tubes. Each spar had five different sized tubes which slid perfectly over each other, the smallest section was the longest, then the next three were each a bit shorter than the next. The shortest had the biggest section and ran only to just outside where the main gear trunnion is mounted. Sounds like an easy replacement but no, once the tubes were slid together with one end all lined up, the spar was put in a press which kinked the spar into it's dihedral, the kink being just about where the main gear trunnion is. Therefore once the kink is performed, there's no way to take the tubes apart and corrosion was getting in between the different tubes.
All the formers to make the tubes have been long gone, so a new set had to be made. I'm wondering if to make it worth while, many sets of new spars have been manufactured allowing for a lot more Spitfires to be restored. A corroded spar being the main reason to ground the aircraft.
