Mk. XXI or Mk. 21
 

When marks came to high numbers, like with the Spitfire or the Mosquito, what was the official Air Ministry designation during WW2: Mk. XXX or Mk. 30?
I can read both in books and articles but all of them were writen after WW2 when roman numbers were dropped out.

Chris

Re: Mk. XXI or Mk. 21
 

Hello Chris:

I checked Janes All the World's Aircraft 1945-46, which was issued in Feb 46. Noted the following:

• Spitfire Marks are designated with Roman numerals to Spitfire XX, thereafter Spitfire 21 and 22
• UK production Mosquitos with Roman numerals to Mosquito N.F. Mk. XIX, thereafter Mosquito N.F. Mk. 31, but also note Canadian production with Roman numerals to Mosquito B. Mk. XX, thereafter Mosquito F.B. Mk. 21
• Beaufighter went from Beaufighter XII to Beaufighter 21 (Australian production), no Mks between XII and 21
• I also checked designation of the Rolls-Royce Merlin engine, it went from Merlin XX to Merlin 21

It looks as if it could have been Air Ministry policy to use Roman numerals to XIX or XX, thereafter 20, 21.....

This is definitely outside my usual sphere, but at least I hope the above gets things started.

Cheers

Don (Boomerang)

Re: Mk. XXI or Mk. 21
 

Hi Don,

I suppose the Air Ministry was frightened by the idea of having a Seafire Mk. XLVII...

Re: Mk. XXI or Mk. 21
 

Chris:

Suspect you are correct.

I am now trying to decide whether to give my age as 53, or LIII.

Cheers

Don

Re: Mk. XXI or Mk. 21
 

Try 45 (VAT not included)!

Re: Mk. XXI or Mk. 21
 

There was a change of policy in 1948 so that all RAF aircraft since have used Arabic Numbering System, rather than Roman System to denote different mark

http://en.wikipedia.org/wiki/British...nation_systems