What are spoilers in boeing?How diffrent are they from ailerons?

Answer 1

Although Engineers put a lot of energy into minimizing drag, they have also created devices solely to produce more drag. SPOILERS are deployed from the upper surfaces of wings to spoil the smooth flow of airflow,reducing lift, increasing drag, and decreasing stall speed. On some aircraft spoilers are used for roll control , one advantage being the virtual elimination of adverse yaw.
To turn right, for example, the spoiler on the right wing can be raised, decreasing some of the lift and creating more drag on the right. The right wing drops, and the airplane banks and yaws to the right.
Deploying spoilers on both wings at the same time allows the aircraft to descend (with the help of flaps) at a greater angle with out gaining speed, and is the principle method of glide path control in many gliders and sailplanes.
Spoilers are also deployed to help shorten ground roll after landing. By destroying lift, they transfer weight to the wheels,improving braking effectiveness.

Ailerons( French for "little wings"btw) are located on the rear (trailing edge) of each wing near the wingtips. The ailerons are used to control roll (rotation along the longitudinal axis).
When an aileron is lowered on one wing the other on the opposite wing is raised.
When an aileron is lowered, the angle of attack on that wing is increased, which increases lift and drag. When a aileron is raised
the angle of attack is decreased, which decreases lift and drag.
The operation of the ailerons permits rolling (banking) the airplane
to desired bank angle. This turns the airplane. (NOT the rudder as some think)

But what do I know, I am but a lowly single engine piston driver

Answer 2

Most of the answers are wrong about the purposefulness of the two. They are actually used together in a lot of planes.

The wing of a large aircraft like the generic Boeing (?) uses a very complicated wing surface articulation. *It is not at all like a Cessna in its functions*. Depending on the speed of the aircraft different sections of the rear edge of the wing are moved up or down to increase or decrease lift on one side of the plane or another. This rolls the plane.
-The spoilers in general are used to either slow the plane or kill lift on both wings to descend.
-The next time you take a trip on a plane take a look at how the functions change when the flaps are extended. When the flaps are extended the low-speed ailerons need help so the spoilers are applied assemtrically (only on the wing that needs to go down). They change their name during this phase of flight to "spoilerons". You'll see the spoilers pop-up fluidly just like any other surface to bring that wing down.

The B-52 and Mitsubishi Mu-2 don't use conventional ailerons at all! They uses "spoilerons" alone. The B-52 would twist the wings off if you used a conventional aileron (don't know why the Mu-2 uses them).

** Spoilers are NOT the same as Airbrakes **.. Spoilers kill of lift while airbrakes (in pure form) only create drag. and can be located either on the wings or on the tail.

Answer 3

Each previous answer has bit of merit but is not complete.

On transport category (like Boeing) airliners it is not unusual to have both ailerons and spoilers used for roll control.

Ailerons are situated at the trailing tip (rear - end) of the wing and move in opposite direction from each other.

Spoilers move independently (only up) when a roll is commanded, only one deploys. They are sometimes also used as speed brakes (both deploy at the same time) in the air as well as during landing along with dedicated lift dumpers (multiple spoilers deploy at a higher angle). They are situated mid-wing.

Most General Aviation (smaller) aircraft use only ailerons, though some, like the MU-2 only use spoilers.

Answer 4

Spoilers (aka Air Brakes) are used to help slow down an aircraft by disrupting airflow over the wing.
They are generally used whilst descending during approach to land and allow the plane to be descended at a higher vertical speed whilst maintaining the same airspeed. Allow me to explain:

If a plane is on its descent and needs to be at a certain altitude by the time it reaches a certain point, whilst retaining the same airspeed all the way along, the throttles can be pulled back to reduce thrust meaning that the aircraft has to descend at a faster rate to maintain the same airspeed; however if the throttles are at the idle position and a fast enough rate of descent is still not being achieved, the spoilers can be deployed, meaning that the aircraft will have to descent at a faster vertical speed in order to retain the set airspeed.

Note that airspeed (i.e knots/mph) is a completely different measurement to vertical speed (feet per minute/meters per minute).

Hope this wasn't too confusing!

Answer 5

Basically, the purpose of the ailerons is to make the plane bank(turn), and the spoilers pop up on landing and are there to cut off the wind flow on the wings and make the plane slow down.

Answer 6

ailerons are the flaps on each end of the trailing wing of any type of aircraft, they are used to bank the plane while turning. Spoilers are like speedbrakes, they are flaps on top of the wing that pop up on landing to help slow the airplane down.

Answer 7

ailerons on opposite wings move in simultaneous different directions ie one up and the other down to effect the amount of lift in a wing. The one going down increases lift - the one going up lowers lift so the plane tends to roll. The spoilers deploy and disrupt airflow causing drag and are used for slowing down the plane

Answer 8

ailerons move through the at rest position, either up or down, and thereby change the chord of the wing...increasing, or decreasing it's angle of attack, and it's lift ability.

Spoilers disrupt the flow of air, causing drag, but because their "base position" is a fixed "pocket" in the wing, and that remains in place, no change of chord happens.

Sorry, but that's the best I can do without pictures.