why is it that passenger aircraft have upturned wings whereas fighter jets have pointy down wings?

Question

No apologies for the technical language!

Answer 1

Upturned wings are said to have Dihedral. This makes the lift vectors spread out away from the airplane making it "want" to stay wings-level. If you try to roll the plane the dropping wing increases its lift vector (L) while the raising wing loosing some lift as they appear to the ground. It is harder to roll a plane with a lot of Dihedral angle to the wings. This adds greatly to the comfort in an airliner and lessens the rocking sensation.

This is behavior you want on an airliner but not on a fighter. On a fighter you want very little effort to roll and don't really care about a "stable" wings-level ride.

It is not true that anhedral makes a plane more responsive. The most responsive you can build a plane will be a 0 degree dihedral. This makes the force vector exactly 90 degrees from the center line. Anhedral is rather used on high wing aircraft and accomplishes the same goal as dihedral does with low/mid wing aircraft. The C-5A has a very pronounced anhedral and is obviously not a highly maneuverable aircraft.

Answer 2

The upturned wings (dihedral) are incorporated in civilian aircraft to enhance stability. However, manoeuvrability suffers because of the upward sweep of the wings. In military aircraft the downward swept (anhedral) wings are a lot less stable but manoeuvrability is increased significantly.

Answer 3

If you've ever made paper airplanes, up turned wings will always make the plane fly better. If you make it so it has down turned wings it'll either roll over and crash or fly upsidedown. Try it!

But what about planes like the C-5 Galaxy, C-17 Globemaster, Antonov 124. Does it have anything to do with being a high wing, cargo plane, being huge or none of the above..

Answer 4

The "up pointed wings" are dihedral, and increase stability in all aircraft, something of paramount importance in a passenger aircraft.

Modern fighters have a bit of the reverse, anhedral. It creates more manouveribility, and is inherently unstable. The fly-by-wire systems in modern fighters help to control the aircraft.

Answer 5

it has to do with stability, the angle of the wings from root to tip(airplane body to wingtip) give the aircraft either excelent response(fighter), or excelent stability(pretty much every other plane). fighters are said to be inherently unstable due to the way the wings are "pointed" in relation to say a cessna 172. aerobatic airplanes follow the same principle. a cessna 172 wouldnt be able to do the maneuvers that say an extra 300 does, due to the angle of the wings. hope that helps.

Answer 6

Pointy down wings (the technical term is "anhedral") make an aircraft unstable but very responsive. The opposite term is "dihedral". This makes the aircraft very stable but slow to turn. Fighter pilots are highly trained to cope with a responsive aircraft, but civilian passengers are not! Now pass the sick bag......

Answer 7

A greater force is exerted on the wings of fighter aircraft that enables it's 'pointy down' wings to make the aircraft move with considerably sharper movements than a passenger craft.

This is why 'pointy down' wings are not on passenger craft...doing 'bullet eights' and 'loop-de-loops' is not a critical requirement for passenger craft and doing these kinds of things tends to REALLY p**s the passengers off.

No apologies for the lack of 'technical' explanation, but this is basically it!

Answer 8

ooooh......! budah ..next question, why fighter jets have ejector seats and passenger aircraft don`t.?

Answer 9

due to the speed fighter jets fly they need more stability.

Answer 10

stability.