Funny thing that the very last operator of the Draken is going to be the US Air Force Test Pilot School. And that will be with a plane which had its first test flight over fifty years ago.
The US planes are, however, the very youngest Drakens - only 30 years old. They are two seaters which were ordered after the Draken production line had been closed down. The Royal Danish Air Force needed a few more two seaters in the mid 70'es when they changed the training program and retired the Lockheed T-33.
The Danish Drakens were rather different compared to the rest. They were based on the J-35F Draken, but not only were they produced to NATO standards, they we also contrary to all other Drakens optimized for the ground attack role. And they were much heavier. Even if we called them F-35 (or RF-35 for the recce capable version), then SAAB called them A-35XD - A for Attack and XD for Export Denmark. No other Drakens carried the A prefix. Most had the J prefix for fighter interceptor, others had S (recce) or SK
(two seat trainer).
Flygvapnet (Swedish Air Force) operated the following Draken versions:
J-35A - initial fighter version - most of them soon rebuilt as SK
J-35B - improved J-35A with new and more powerful afterburner.
-35C - two seat trainer - mostly from rebuilt J-35A.
J-35D - very much improved J-35B.
S-35E - recce version of J-35D.
J-35F - last production fighter version with more powerful engine and new weapon systems.
J-35J - extensively upgraded former J-35Fs awaiting JAS-39 Gripen service introduction.
All Austrian Drakens are ex-Flygvapnet J-35Ds.
Finland operated a mixture of J-35B, -D and -F versions, some new built and some ex-Flygvapnet.