Usually planes are able to fly when air moves across the wings which generates lift. But how do fighter jets able to maintain lift while performing aerobatic maneuvers?

Question

Usually planes are able to fly when air moves across the wings which generates lift. But how do fighter jets able to maintain lift while performing aerobatic maneuvers?

In: 342

Answer 1

The ELI5 version is that they still create lift while doing most aerobatics. More advanced aerobatic planes have semi or fully symmetrical airfoils so that they generate lift upside down as well as right side up.

The higher level explanation gets into what lift actually is…. And this discussion can hurt even college level physics students heads. We will skip Coandă and just lightly touch on Bernoulli and Newton.

Bernoulli the theory is that the shape of the wing creates a low pressure area on the top of the wing and the higher pressure at the bottom tries to fill that lower pressure. You can demonstrate this by taking a dollar bill, holding it between your index and middle finger by one end and letting the bill lay on top of your ring and middle fingers. You then gently blow across the top and when you get the angle correct the bill will float off your fingers.

Newton can be shown with the exact same set up, but blow on the bottom of the bill and it will just float off your fingers as well.

Just for fun the Coandă effect has to do with how the fluid mass wants to stay attached to a surface, when that surface flows down at the end the fluid stays attached and as it runs off the back of the wing it has a slight downward motion which pushes up.

The simple point is that all of these are part of what creates lift and that does not change when an airplane is doing aerobatics. For example in a level competition roll the top of the wing is creating lift, then when you get the wing vertical the fuselage of the airplane is actually creating lift (pure Bernoulli) and the the bottom of the wing and then the fuse, then the top of the wing again. And it is not like they turn off or turn on suddenly. It might start at 100% wing and zero fuselage and then as you roll it goes 90/10, 80/20, 70/30 till you reach 50/50 and then it starts reversing 40/60, 30/70 till it is 0/100 wing/fuse and then just keeps going till you are 100% inverted wing etc.

The posters claiming pure power… Most aerobatic planes, and most planes period, don’t have a more power than weight. For example the Extra 330SC weighs 1720 pounds and has 315HP… It simply can’t hover because it does not have the power to weight ratio needed.