Adding to my previous post, basically a data plate is a part on an aeroplane, just like a bolt or an inspection hatch. If it gets damaged or misplaced, you can put a new one on it. I don't really agree with the theory that a data plate 'holds' an identity. From a historical and accuracy point of view, it would be great to have an airframe with the original data plate that was installed at the factory at time of build. We can all agree on that.
An identity is expressed or validated by having a data plate in a specific location, same as with vehicle identification numbers in a specified location on the car's body. If it is not possible to confirm that identity, because the data plate itself was lost, damaged beyond recognition or taken away by souvenir hunters from a crash site, you can still use existing documentation (operations logs, period news articles, recognised databases) to link an identity to a pile of metal recovered from a crash site. You will have to add a new data plate to the airframe at some point during the rebuild, that's all.
The way it works is that if you recover a certain amount of material (authorities do not publish a percentage or other limit as far as I know) from a crash site and the identity of those remains is known, you can then 'claim' that identity as belonging to that pile of metal. If that pile of metal enters a shop and at some point in time a complete-looking airframe emerges from that shop, you can claim to have restored that particular aeroplane with that identity. From an airworthiness point of view, you need to show that the result of your work conforms to the drawings, specifications and such as originally created by the design office. If you can do that, you will then have a P-51 for example. If the trail between original airframe, crash location, pile of metal and your resulting P-51 is clear enough, you can register that P-51 as being that original aeroplane, or a direct descendant of it if you will. There may well be distinct differences between the original and the end result of your work (for example, the P-51D wing on Thunderbird, I think it was mentioned before). But the authorities recognise that there are and will be variations within a type, all of which still within the specs of the type.
Where the water gets muddy is when you start looking at all the restorations over the years where parts from several airframes have been mixed up to create flying airframes. Go back 50 years and getting a P-51 in the air meant using a fuselage (with a specific identity most likely) that was known to be good, using a set of airworthy tail feathers and two good wings, bolting everything together and thereby having a flyable P-51. These days we can either build complete fuselages and everything else from scratch and because of that create a flyable P-51 even though the original bits resembled nothing more than metal cornflakes, or we painstakingly take bits of metal cornflake and beat, form, treat them back into a useful part. That second option is less likely to occur on potential flyers, but it's more likely to occur now than 50 years ago.
So the mis-matched airframes that were restored a long time ago are now having us scratch our heads in confusion. Which identity is the 'real' one? The leftovers from those old restoration projects can create their own headaches if they are then used to create another restoration project, claiming the same identity. I think that's what happened with that P-51 duo mentioned earlier.
On one end we have to realise that historic accuracy is going to be very difficult if you want to keep an airframe in the air. The practice of swapping out parts is not unique to the warbird world. Most BAe Hawks went through a 'fuselage replacement program' at some point. Hawk goes into the hangar with identity X, Hawk comes of of the hangar, still with identity X, but there's a fuselage laying about that used to be bolted to data plate X.... It's not going to be used in a rebuild, but the potential for one of our head-scratching situations is certainly there! On the other hand, we are getting better at keeping airframes as original as possible, or restoring them back to how they were. In the end everything that happened to an aeroplane during its life is part of its unique heritage. We have to accept that very original time capsules are only to be found in museums, in a glass case, and flying airframes have a history that may include lots of work throughout the years to keep it in the air or get it back there. As long as we're honest about this we can enjoy seeing, hearing and smelling a P-51 do what it does best.
Going back to one of the questions asked earlier:
Would the FAA recognize slapping a DP from a Pacific wreck on a essentially new aircraft with no original parts from an aircraft aircraft NOT in your possession or ownership?Most likely not, but if you went through the trouble of recovering as much as possible from that Pacific wreck you can then do as suggested. You just have to make sure that the wrecked parts are either stored securely (you could sell them along with the restored airframe) are recycled into something else that prevents them from being used in a different restoration (you can buy keytags made from metal from currently flying restorations.... go figure), or are kept off the market in some other way.
The Mosquitos being restored by Avspecs use a new-built fuselage with new-built wings and tail feathers. Going by weight, a very significant percentage of a Mosquito is metal, in engines, gear, loads of fittings, brackets, frames and such, so you need a complete Mosquito before setting off on such a restoration. But where is the original Mosquito if what is flying around is all new wood? Has anyone looked into what happens to the original fuselage and wings?
That's enough typing for now. It's just my two cents worth of course.
_________________
A Little VC10derness - A Tribute to the Vickers VC10 -
www.VC10.net