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Questions tagged [spoilers]

Spoilers are control surfaces which spoil the lift and increase the drag of a wing by disturbing the airflow around it.

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Why does one of the Boeing 777's spoilers deploy differently from the rest?

There is one spoiler that isn't totally deployed. Look: Source: Airliners.net And also on this other picture: Source: Airliners.net Why aren't they deployed at the same angle?
user13197's user avatar
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42 votes
6 answers
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Do airplanes need brakes in the air?

A few days ago I flew on a Boeing 737-900ER. Luckily I was sitting just beside the left wing, seat 26B. I observed that the spoilers were activated (opened) just after the pilot spoke on the Passenger ...
AirCraft Lover's user avatar
21 votes
2 answers
16k views

When can spoilers be used on airliners?

On airliners, are spoilers used in any part of flight other than landing?
Taher Elhouderi's user avatar
20 votes
2 answers
3k views

Why do modern jetliners provide Thrust Reversers at all in their design decisions?

Let's start with the following knowns (please correct me if I am wrong about any): The braking force provided by the wheel brakes is much larger than that by the thrust reversers One is not allowed ...
curious_cat's user avatar
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19 votes
1 answer
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How frequent is the use of spoilers during descent?

Having flown a number of flights as a passenger recently, I observed that: Roughly 50% of pilots used spoilers above FL180 Almost everybody used spoilers to pass the 10,000 feet / 250 knots mark ...
kevin's user avatar
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18 votes
5 answers
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Why can't wing-mounted spoilers be used to steepen approaches?

In a comment on this answer to my previous question about tail-mounted airbrakes (lack of), @JohnK states: You won't see flight spoilers (speed brakes) being used to steepen approaches. You have to ...
Vikki's user avatar
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17 votes
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Do flaps have a maximum speed limit but spoilers don't? Why?

This related question on Aviation SE describes how in most aircraft spoilers (flight spoiler mode not ground spoilers) are deploy-able at any speed But flaps on the other hand mostly have a V_FE above ...
curious_cat's user avatar
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15 votes
1 answer
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Why are there large gaps in the spoilers of the Airbus A300?

The spoilers on the Airbus A300 have large gaps at the bottom: (A300-600R, modified from Wikimedia Commons, original picture by Tennen-Gas, CC BY-SA 3.0) I have never seen any other aircraft with ...
Bianfable's user avatar
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14 votes
2 answers
4k views

Is roll control achieved exclusively with spoilers on an A320 on final approach?

As a private pilot I have zero knowledge about how big jets are being flown so I was a little surprised to see that smaller Airbuses (A32x) only use spoilers for roll control on final approach. ...
Philippe Leybaert's user avatar
14 votes
8 answers
2k views

Could flaps be raised upward to serve as spoilers / lift dumpers?

I should preface that I'm by no means an aviation person. I'm just in a aircraft knowledge obsession phase and daydreaming about designing my own ultralight (will never happen). The idea would be to ...
Adel's user avatar
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14 votes
1 answer
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Why does spoiler extension cause straight-wing Learjets to pitch down, rather than up, and why did it take so long to discover this?

Straight-wing Learjets (the 23, 24, 25, 35, and 36), the first generation of the popular business-jet series, are (especially when not equipped with any of the many first- and third-party wing ...
Vikki's user avatar
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13 votes
5 answers
6k views

For large commercial jets is it possible to land and slow sufficiently to leave the runway without using reverse thrust or brakes

I have long wondered whether its possible (in theory at least) for jetliners under typical loading scenarios (pax and cargo), landing at a normal airport such as LHR to come to a slow enough speed to ...
robbie70's user avatar
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11 votes
3 answers
5k views

Why do some aircraft (e.g. Avro RJ85) have rear-mounted air brakes?

I recently saw an Avro RJ100 on approach and I wondered why the Avro RJ100 and also the RJ85 have the air brakes at the rear of the aircraft, and not on top of the wings like most airliners? (...
Pascal's user avatar
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1 answer
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Why is the speedbrakes rate of retraction 25 seconds when used at speeds greater than 315 knots/.75 Mach on the A320?

While I was routinely reading the FCOM normal procedures I came across a note with regard to the speedbrakes retraction time going up to 25 seconds when we use them at speeds at or over 315 knots / ....
Jai's user avatar
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11 votes
1 answer
478 views

Why are the spoilers used as the backup controls instead of ailerons on the Boeing 777?

While reading this question, I ran across an interesting unanswered comment. Why did Boeing choose to use some of the spoilers as mechanical backup controls rather than the ailerons?
dalearn's user avatar
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11 votes
3 answers
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Do aircraft using only spoilerons for roll control, with no conventional ailerons, have a crossover airspeed?

Airplanes generally have a crossover airspeed (a minimum airspeed below which directional control of the airplane cannot be maintained in the event of a rudder hardover). This is because, as airspeed ...
Vikki's user avatar
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10 votes
1 answer
2k views

Is the location of an aircraft spoiler really that vital?

I was wondering that spoilers in most of the aircraft are always placed aft (towards the tail) the CG location. Why aren't they placed ahead of the wings or near the nose of the aircraft? The same is ...
CuthillMckee's user avatar
10 votes
4 answers
21k views

What are the differences between air brakes, spoilers and lift dumpers?

So many people use these words interchangeably, but after a little searching on Google, I found they are not quite the same thing. All the links I read explain things in a misleading way which pushed ...
Taher Elhouderi's user avatar
10 votes
1 answer
2k views

Why shouldn’t the A330/40’s speedbrakes be used in alternate law?

On page 30 of the ATSB report into the QF72 accident (page 50 of the PDF file of the report), in a table describing the actions required of the flightcrew in response to some of the ECAM messages ...
Vikki's user avatar
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9 votes
2 answers
4k views

Should spoilers and reverse thrust be deployed before nose gear touches down?

On airliners, should spoilers and reverse thrust be deployed before nose gear touches down? I used to thought that deploying them will affect the handling characteristics, so it is best to wait until ...
kevin's user avatar
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8 votes
1 answer
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Do all 767-200s have speedbrakes that deploy automatically upon touchdown?

It may just be a coincidence, but I found two videos that involve the 767-200's speedbrakes not deploying automatically upon touchdown (which should occur if they are armed). The first video shows the ...
Charles Nicholson's user avatar
8 votes
2 answers
2k views

Is a plane stalled during landing rollout?

IMAGE SOURCE: https://pilotinstitute.com/wp-content/uploads/2022/01/Parts-of-a-Wing.jpg As the lift dumpers are extended on landing they cause the air to move away from the wing. Also as the flaps are ...
Aviation Enthusiast's user avatar
8 votes
1 answer
2k views

What is the purpose of proximity sensors on hydraulic systems?

One of the planes I worked on had ground spoiler response checked with proximity sensors. The reason mentioned for that was - "The ground spoiler is hydraulic only - hence its response will be checked ...
user2927392's user avatar
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7 votes
4 answers
4k views

Why do spoilers seem to be slightly activated during take off?

In this video (minutes from 10:46 to 11:00), the spoilers seem to be slightly deployed during take off. What's the purpose of this? I've already seen this in other videos too. I've also read the ...
Claudi's user avatar
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7 votes
1 answer
4k views

Why is deploying speed brakes not recommended with the flaps extended?

I read this in the normal procedures section of the A320 FCOM. Why is it so? When the speed brakes are deployed, extending the flaps beyond FLAPS 1 may induce a slight roll movement, and in calm ...
Jai's user avatar
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6 votes
1 answer
454 views

Why are spoiler panels 5 and 10 locked in high speed flight on the B777?

From the Boeing 777 FCOM: Spoiler panels are used as speedbrakes to increase drag and reduce lift, both in flight and on the ground. The spoilers also supplement roll control in response to control ...
Joriddles's user avatar
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6 votes
2 answers
609 views

What determines spanwise placement of spoilers for roll control?

Specific application of spoilers was discussed in What is the benefit of spoilerons compared to ailerons? As I remember it, 40yrs ago gliders had spoilers close to the wing tips - perhaps slightly ...
jwzumwalt's user avatar
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5 votes
5 answers
3k views

How can you move the thrust reverser to another part of the airplane? [closed]

So this is what we need to research simply: Is there a way we can remove the thrust reverser from the airplane and have something else take care of it? My initial thought was maybe we could put ...
user avatar
5 votes
2 answers
584 views

Why are the B-52's vortex shedding panels angled?

Their function is here: What is the purpose of the serrated trailing edge spoilers on the B52? While watching this video (around the 1:53 mark), I noticed a number of angled devices on the trailing ...
dalearn's user avatar
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4 votes
4 answers
485 views

Could flaps replace spoilers by deflecting more than 90°?

Could flaps replace spoilers by deflecting more than 90° after touchdown?
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4 votes
4 answers
616 views

Why don't I see this kind of split ailerons on aircraft?

Why don't I see split ailerons that work like spoilers going up and like normal ailerons going down? Isn't that a good way to get rid of adverse yaw? Adverse yaw is caused by difference in drag for ...
xvel's user avatar
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4 votes
1 answer
210 views

How can speed brakes level a plane?

I copy pasted YouTube's transcript at 2 minutes and 22 seconds. Sweeney refers to then Major Kevin Sweeney, retired as Lt. Col. NARRATOR: Speed breaks are devices on airplane wings designed to ...
Wes's user avatar
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4 votes
1 answer
2k views

Why do outboard spoilers deploy more than the inboard spoiler on the A320?

I was reading in the FCOM about the speedbrakes and ground spoilers when I came across the below lines. The maximum speedbrake deflection in manual flight is: 40° for spoilers 3 and 4 20° for ...
Jai's user avatar
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3 votes
4 answers
2k views

Why would the Speedbrake be required for such a long time on approach? [duplicate]

As far as I was aware, the Speedbrake is designed to slow the aircraft down. On landing, I do understand why they are required. Once the aircraft has hit the tarmac, they are deployed to 1) slow the ...
cmp's user avatar
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3 votes
1 answer
254 views

Why is the speed brake lever not a "spring" one that returns to the default position when released?

I was watching this video in which are described various systems on B737 but at around 6 minutes, it talks about speed brakes and necessity for pilots to maintain their hand on the lever to avoid ...
Luca Detomi's user avatar
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3 votes
2 answers
687 views

Are spoilers primary or secondary flight control surfaces?

The literature on primary and secondary flight controls is very contradictory. My professor provided this image from which I infer that spoilers are used for primary flight control: Also, here it ...
Yaso's user avatar
  • 111
3 votes
1 answer
551 views

Why is there a difference in the max spoilers extension between the A320 and A321 in a roll?

I was recently reading the Flight Controls chapter in the FCOM and I read that spoilers 2-5 extend a maximum of 35 degrees on the A320 however on the A321 spoilers 2,4 & 5 extend a max of 35 ...
Jai's user avatar
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3 votes
1 answer
799 views

What is the term for an aileron that’s also used as a ground spoiler?

Ailerons and spoilers1 have a considerable amount in common; both are wing-mounted panels, hinged at their leading edges, that move up and/or down to alter the aircraft’s aerodynamic characteristics. ...
Vikki's user avatar
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2 votes
3 answers
901 views

On the 737NG, after deployment of spoilers automatically after landing, do the spoilers automatically go back down?

So, I was just wondering whether the spoilers on a 737-800, after automatic deployment when landing, will go back down automatically, or need manual input by pilots for the spoilers to go down.
lpydawa's user avatar
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2 votes
1 answer
194 views

How can PreciseFlight speedbrakes double the drag while being so small?

Look at this photo of some PreciseFlight© speed brakes: On the website it is claimed that these little red plates can double drag and descent rates. I cannot believe that. Can this be true, and if ...
TheEagle's user avatar
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2 votes
2 answers
683 views

Why do we have to check the speed brakes during GPWS memory items on an A320?

Just out of curiosity, I want to ask why do we have to check that the speed brakes lever is retracted during a GPWS (Ground Proximity Warning System) maneuver using the A320 memory items? It clearly ...
Islam Elsayed's user avatar
2 votes
1 answer
1k views

Do the different spoilers on an A321 extend by different amounts? [duplicate]

I recently flew with an A321 and watched the left wing while the pilot tested the control surfaces before lift off. I noticed that one of the spoilers angled upwards much less than all others. In the ...
Daniel Sk's user avatar
  • 123
1 vote
1 answer
556 views

Why is the pilot in this video retracting the spoilers so shortly after landing?

I watched this video (link with time) and wondered why the pilot has retracted the spoilers so shortly after landing. Because the runway is wet and it looks like the plane is still quite fast even in ...
Noah Krasser's user avatar
  • 9,002
1 vote
2 answers
203 views

Do the 787 Flight Spoilers have variable deployment when using the Speedbrake?

On the Boeing 787 (other Boeing models welcome too) while in-flight and/or on the ground do the SpeedBrakes/Spoilers have a variable amount of deployment (in angle) between the "ARMED" and &...
Greg R.'s user avatar
  • 15
1 vote
1 answer
596 views

How does the spoiler actuation mechanism work on the Airbus A340?

How does the servo control spoiler actuation mechanism on the Airbus A340 work?
Victor Juliet's user avatar
1 vote
0 answers
166 views

Is there any reason spoilers would deploy just after liftoff? [duplicate]

I was watching this video of a 747-8F taking off. http://www.dailymotion.com/video/x273atd Just after liftoff the air brakes and ground spoilers deploy on the left wing causing a sharp roll to the ...
TomMcW's user avatar
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1 vote
0 answers
103 views

Why don't some spoilers plates fully open in most airliners? [duplicate]

The following image illustrates my question: What's behind the manufacturer decision of opening some spoiler plates less or more than the others? I noticed this is quite common in airliners.
Germano Cavalcanti's user avatar
0 votes
2 answers
683 views

Why does spoiler extension during touchdown cause a pitch up moment?

There are reports that incorrect flight technique associated with spoilers extension during touchdown were contributing factors to pitch increase after landing, causing tail strikes in jet transport ...
Petr73's user avatar
  • 3
0 votes
1 answer
221 views

Which system on the 737NG decides the use of roll spoilers?

Which of the 737NG systems decide to use roll spoilers? FMC? Some other flight surface controller? Does it trigger when airspeed is low?
lpydawa's user avatar
  • 1,248
-1 votes
3 answers
258 views

If spoilers are released in flight without descending, what could happen? [closed]

If spoilers are released in flight without descending, what could happen?
Raimdod's user avatar