Originally Posted by
megan
Anorak here. By rights the F-35 should be the Lightning IV. The very first Lightning was the P-38, though an American aircraft the name was bestowed by the British, in British service to be known as "Lightning Mark I", and a one off P-38, "Lightning Mark II". For the US the F-35 is indeed a Lightning II, as they never enjoyed
newt's Lightning Mk. III except by way of exchange.
In UK parlance the F35 is known simply as ‘Lightning’. All numbers have been dropped. Interestingly, the USAF are now calling it the Panther (same vein as they renamed the Fighting Falcon the Viper)