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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12
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0answers
113 views

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 ...
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2answers
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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 ...
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1answer
191 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?
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7answers
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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 ...
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1answer
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 ...
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5answers
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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 ...
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4answers
281 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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3answers
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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.
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1answer
78 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?
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4answers
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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 ...
3
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1answer
928 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 ...
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1answer
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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 ...
6
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1answer
197 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 ...
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0answers
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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 ...
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3answers
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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? (...
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0answers
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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.
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1answer
422 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 ...
9
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2answers
2k 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 ...
17
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1answer
3k views

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 ...
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2answers
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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?
7
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1answer
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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 ...
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2answers
2k 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 ...
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4answers
13k 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 ...
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4answers
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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 ...
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2answers
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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 ...
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1answer
445 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?
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2answers
13k views

When can spoilers be used on airliners?

On airliners, are spoilers used in any part of flight other than landing?
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2answers
2k 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. ...