The F-35, known as the F-35 Lighting II, is the most advanced fighter aircraft in the United States’ arsenal. It’s often referred to as the “fat Amy” by some people due to its heavy-weight design compared to other fighters. This name wasn’t an official name assigned to the aircraft, but it came as an unofficial nickname much like the F/A18’s nickname “Rhino”.

The reasoning behind the “fat Amy” nickname is due to the F-35 b being much larger and heavier than previous fighter aircraft. It is powered by an F135 engine and the high thrust-to-weight ratio at the maximum takeoff weight is 1.07, which is much higher than many other fighters. The aircraft weighs in at over 33,000lbs loaded with fuel and weapons, making it substantially heavier than other aircraft like the F/A-18, which weighs less than 28,000lbs. It also has a wingspan of 35ft, wider than the F/A-18’s 32ft Wingspan.

The term also might be due to its high operational costs, as the cost is believed to exceed over $300 million USD per aircraft in some cases. The F-35 has been known as the most expensive weapon system in history. This has caused some to refer to the aircraft as “fat Amy”, as they feel it is too costly and not necessarily worth the money.