While the first prototype of the Northrop F-5, unofficially dubbed the 'Freedom Fighter' in its initial F-5A/B form, made its maiden flight back in July 1959, the type remains a useful asset in the modern era. The Spanish Air Force received 70 such aircraft between 1968 and 1971, produced under licence by domestic manufacturer CASA. They comprised fighter, reconnaissance and trainer versions. Today, only the latter remain in use - 19 of them, used as lead-in fighter trainers and 'aggressor' aircraft. The sole wing flying them is Ala 23, based at Talavera la Real in south-western Spain. An upgrade programme has made the Spanish F-5s (given the local designation AE.9) fit for the modern era, producing the SF-5M model with more advanced avionics. These enable greater compatibility with the front-line fighters in the Spanish Air Force inventory, the EF-18 Hornet and the Eurofighter EF2000. These very rare visitors to the Air Tattoo will be on static display and we believe this is the first time Spanish 'Freedom Fighters' have attended a British event.