The following units can be upgraded to Jet Fighter:
Jet Fighters have greater range than regular Fighters, and they are better at intercepting and destroying enemy aircraft.
The introduction of jet engines to fighter aircraft changed the way man wages war in the skies. The primary impact was that of speed, since even early jet engines were able to outperform their rotary peers by three to one. While this improvement was certainly appreciated by their pilots (speed advantages often translate to more options in air combat), it was some time before the nature of this change was fully understood. Dogfighting became a significantly more difficult task, since the window to "take a shot" was reduced to an instant. The introduction of guided missiles helped address this, as well as increase engagement ranges to beyond what the pilot could visually see. Though missiles dramatically changed air combat, cannons still remained a staple of the vehicles' arsenal. Missiles could be jammed, and early attempts were fraught with unreliability. Without a backup weapon, pilots were often at the mercy of inferior planes, but ones where the pilot wasn't relying on shaky, emerging technologies.
The Jet Fighter closely resembles the real world F-16 Fighting Falcon.