"The test pilot flying the F-35 makes it very clear that the new jet, even in its ideal configuration without any external stores, was no match against a Block-40 F-16C in a less-than-ideal configuration with a pair of under-wing fuel tanks:
Even with the limited F-16 target configuration, the F-35A remained at a distinct energy disadvantage for every engagement."
"And to add insult to injury, the JSF flier discovered he couldn’t even comfortably move his head inside the radar-evading jet’s cramped $#@!pit. “The helmet was too large for the space inside the canopy to adequately see behind the aircraft.” That allowed the F-16 to sneak up on him."
http://foxtrotalpha.jalopnik.com/the...igh-1714712248
The only way the F-35 was able to beat the F-16 was a desperate maneuver that is too risky for anything else but a 1:1 engagement.