The more I watch videos of the F-16 and the F-22, the more the aerodynamic differences stand out. I’ll address three separate issues: the wing root vortices generated at high angles of attack, flaperons versus ailerons, and the control surfaces located on the leading edges of the wings (what are those called?). These are just observations, with a general, “why’d they do that,” on a few things.
1) Wing Root Vortices
The F-16’s leading edge strakes generate wing root vortices at high angles of attack that extend the length of the fuselage, due to its blended body design. These in fact increase its stability at such angles by preventing wing root stalling, and I’ve also heard that they help maintain the relative lift capacity of the wings in the same situations.
The F-22 lacks such leading edge strakes because of the positioning of the intakes (which also impede the pilot’s visibility when looking down and back). Vortices are still formed at high AoA, but the most glaring difference is how fast they dissipate in comparison to those formed by the F-16. While those on the Viper extend the length of the entire airframe, those on the Raptor are broken up just behind the cockpit.
2) Flaperons/Ailerons
The F-16 was the first fighter jet to use computer-driven control surfaces, or “fly-by-wire.” Instead of using ailerons to roll the airframe, it instead did away with them altogether and substituted “flaperons” on the inboard trailing edges of the wings. By using a combination of these and the horizontal stabilizers, the Viper rolls.
While the F-22 also uses a fly-by-wire system and rolls similarly to the F-16, it still has ailerons. That’s all I have on this one, just wondering why that is.
3) Leading Edge Thingies
Pardon the highly-technical jargon, but I don’t know the official name of them. Anyways, when the YF-16 was unveiled, its wings were unique in that the leading edges automatically changed their pitch based on pilot input. This changed the camber of the wing, increasing the lift of the wings, and thus making it able to pull much harder turns. On the F-16, the leading edge surface area accounts for roughly 9% of the total wing surface area.
The F-22’s leading edge surfaces account for about 3%.
That’s it, that’s all I wanted to comment on. Since this is about as far as my education in aerodynamics extends (i.e. stuff I read on the internet) any more expert opinions are appreciated. Laters.
