Why do larger birds flap their wings slower than smaller birds? Why don't airplanes use flapping winfs to fly?

Question

Why do larger birds flap their wings slower than smaller birds? Why don't airplanes use flapping winfs to fly?

Answer 1

Who says that there are airplanes without flapping wings???

http://www.ornithopter.org/


Its more of an engineering problem. A flapping wing on an aeroplane creats a major stress point...the hinge.

Answer 2

Larger birds tend to have a larger wingspan, consequently they can push more air than their counterparts and ride air currents more efficiently reducing the need to flap their wing as frequently. Also larger birds tend to fly at higher altitudes using air currents to aid propulsion. Think about the difference between dropping a large flat piece of paper and a small one. The larger one should take longer to hit the ground due to the greater surface area. The effect is more pronounced the higher from the ground the paper falls.

Airplanes do not have flapping wings for several reasons. One which someone has already mentioned, is because it has an engine to provide propulsion. Another reason is that making the wings flap would mean the addition of more moving parts. This would add mass to the plane and would provide more places for mechanical failure.

Answer 3

Aeroplanes are fixed-wing by nature. However, there are Ornithopter Aircraft (not aeroplane) which flap their wings much like birds do.

As for the big bird vs small bird, it follows that the smaller wings need more flapping to get the same lift a larger wing would produce. This is like comparing adults and children walking. Watch closely as kids take more and faster steps that adults do.

Answer 4

Longer wings are more efficient because air turns around wing tips, in fact sailplanes have very long wings and some planes have tanks on wingtips to limit this phenomenon, so little birds have to flap faster.I think this is the reason.
Airplanes are fixed-wing aircrafts for definition, helicopters are rotary-wing aircrafts, and ornithopters are flapping aircrafts.
But ornithopters is more theoretical than an actual technology.
They are too complex, just think about swing-wing airplanes(F-14, Tornado, MiG-23/27, B-1, Tu-160) that are so complex to do, and they only changed their sweep angle while changing their speed, but they are complex, imagine that a flapping wings have also to turn(change angle of attack), not only to flap in order to produce thrust and this makes this technology almost impossible.
I think that only one manned ornithopter managed to fly.

Answer 5

Because their wings are larger, larger birds don't have to flap them as often to fly. Planes' wings don't need to flap. They use engines to "push" the planes through the air.

Answer 6

The flapping is for thrust. The larger wings produce more thrust than smaller wings.

Airplanes don't flap because they have an engine providing thrust.

Answer 7

Larger birds have larger wings therefore creating more lift with fewer strokes.

Flapping wings on a plane would create a very unstable structure (Leonardo DaVInci designed a flyer using this concept). Since planes have engines creating power, their fixed wings can create lift.

Answer 8

I was wondering if he was in engin 110 also... Sounds like a fishy question otherwise...Large birds are slower because of newton's 3rd law. Good luck

Answer 9

No way Jets666 are you in engin 110?

Answer 10

for the same reason people with longer legs take slower strides to travel at the same pace as someone with shorter legs. and because they don't have to.