The Lockheed Martin F-35 Joint Strike Fighter has made headlines for years now, though very rarely for anything other than set backs, cost overruns, and subsequent orders for more of the troubled air-frame. The fighter, which the United States and its allies tout at the most advanced military aircraft on the planet, has yet to really prove its worth in combat, and rumors continue to swirl about just how capable the F-35 would be if it ever had to engage other advanced fighters like Russia’s advanced 4th generation jets, or China’s recently unveiled 5th generation copies of America’s aerial prize fighters.

Lockheed, of course, has changed their tune regarding the F-35’s dog fighting capabilities over the years of development. Originally, champions of the program claimed it would be superior to its international air-to-air competitors, but it soon became clear that the F-35 would be heavier, slower, and less maneuverable than America’s other 5th generation stealth fighter, the now canceled F-22 Raptor, and claims regarding the F-35 shifted to incorporate a different combat strategy.

The F-35, Lockheed explained, would use a combination of stealth, optics, and advanced weapons systems to engage enemy aircraft from the other side of the horizon, eliminating the need for “Top Gun” style fly-by combat. However, even with that understanding, the F-35 still faces another set back when it comes to engaging enemy aircraft: the jet’s internal air-to-air missile carriage capability is limited to just four missiles.

With a growing emphasis on the threats posed by near-peer opponents like China (who has already begun fielding their F-22 competitor, the J-20, and is expected to launch their F-35 approximation, the J-31, next year) and Russia, whose 4++ generation Su-35 boasts maneuverability arguably comparable to America’s F-22, Lockheed may be feeling some heat regarding their crown jewel aircraft. The F-35 relies on advanced stealth technology as one of its primary defensive measures, leaning heavily on beyond-line-of-sight armaments, but with a maximum capacity of only four air-to-air missiles, American jets could easily find themselves outgunned in a skirmish with Chinese or Russian fighters.