Use of speed brakes in flight
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Joined: Apr 2001
Aviation Qualifications: ATPL
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From: various places .....
God bless Sqn Ldr Gell RAF who introduced me to this valuable technique
.. it is comparatively easy to divine those of our PPRuNe band who learnt to fly more than a few decades ago ..... for my group, the precise same technique had all, bar one, solo in 4-7 hours ...
.. it is comparatively easy to divine those of our PPRuNe band who learnt to fly more than a few decades ago ..... for my group, the precise same technique had all, bar one, solo in 4-7 hours ...
Joined: Mar 2003
Posts: 130
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From: Germany
On the CRJ200 you have the problem that with WING + COWL A/I selected on, the pressure at idle thrust is not sufficient to supply both systems, so you have to increase thrust again up to a certain level. Use of speedbrakes is almost always a must in this situation, especially in the latter stages of the approach when you are descending at minimum clean speed.
Apart from this, i agree with most what has been already said on this thread regrding (mis)use of sb...
Apart from this, i agree with most what has been already said on this thread regrding (mis)use of sb...
Joined: Jun 2000
Posts: 4,507
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From: last time I looked I was still here.
If you are considering 'braking the speed' then definitely in the air and level flight. If you are considering increasing ROD then in the air and in descent.
On the ground they are primarily lift dumpers.
On the ground they are primarily lift dumpers.
Joined: Apr 2016
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From: Porirua
Yeah mate,back in the day,doing my F/O 727 time,the Cappy AND the PFE would bark at me for using them,called them the,PPPD,S...(piss poor planning device),and occasionally,more often that not get a clip around the ear,now as the skipper I cringe every time I use them.I can still hear those crusty old ba$$tards barking at me in the after life...." You little Shi$$t,you should have started the decent way back when"......I miss those days
Joined: Nov 2013
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From: Right Seat
Hi aviator3233,
I guess this is question came from an FAA ATP test.
The correct answer is "on ground". But just reviewing the concept of speedbrake, remember that the speedbrake is a function of the flight spoilers, which are also used for rolling combined with the ailerons; the spoilers used on ground are called ground spoilers, they are spoilers that only open on ground. Usually the flight spoilers are also used as "ground spoilers" while on ground, but at an higher angle than in flight. On the 737 aircraft, for instance, the speed brake lever have a flight detent and you should not extend the speedbrakes beyond this detent in flight, because beyond this detent the flight spoilers will open in an higher angle that is designed to be used only on ground. Once you land this kind of airplane, you should see this lever moving automatically to the full extended position; in this occasion, the flight spoilers will be being used as ground spoilers as I mentioned above.
So as you can see, this question is a little bit tricky. But for FAA purposes, choose the "on ground" answer.
I guess this is question came from an FAA ATP test.
The correct answer is "on ground". But just reviewing the concept of speedbrake, remember that the speedbrake is a function of the flight spoilers, which are also used for rolling combined with the ailerons; the spoilers used on ground are called ground spoilers, they are spoilers that only open on ground. Usually the flight spoilers are also used as "ground spoilers" while on ground, but at an higher angle than in flight. On the 737 aircraft, for instance, the speed brake lever have a flight detent and you should not extend the speedbrakes beyond this detent in flight, because beyond this detent the flight spoilers will open in an higher angle that is designed to be used only on ground. Once you land this kind of airplane, you should see this lever moving automatically to the full extended position; in this occasion, the flight spoilers will be being used as ground spoilers as I mentioned above.
So as you can see, this question is a little bit tricky. But for FAA purposes, choose the "on ground" answer.
Joined: Apr 2008
Posts: 525
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From: Nearer home than before!
It's pretty actually pretty simple. The "stick of shame" as it was called in my youth is usually labelled SPD BRK. The clue is in the name... The faster you are going, the more difference they make.
Being high and clean at 210kts and sticking them out does not a lot more than make vibration.... At 320kts you can really alter your profile positively.
Most aircraft only use some panels for speed brakes. Some for roll augmentation, and all for lift dumping.
Being high and clean at 210kts and sticking them out does not a lot more than make vibration.... At 320kts you can really alter your profile positively.
Most aircraft only use some panels for speed brakes. Some for roll augmentation, and all for lift dumping.
Joined: Sep 2008
Aviation Qualifications: ATPL
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From: Scotland
All the old boys and girls from the 732 call it the lever of shame.
In modern slippery aircraft like the 738, it is the lever of necessity if you wish to meet stable approach criteria!
In modern slippery aircraft like the 738, it is the lever of necessity if you wish to meet stable approach criteria!
Joined: Jun 2000
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From: last time I looked I was still here.
Given the LOS label I offer the following mis-understanding.
B757/767. High downwind under radar home base, but could always expect a short turn in if ATC perceived it OK, and if a heavy was out on long finals. You are at minimum clean speed, 210kts. ATC gives a large descent change of altitude from FL 70 - 2000' which is a clue. Choices? Extend Spd Bks and keep speed 210kts? Select flap 1, 210kts, speed brake etc. etc. or as many newbies did, select 250kts. They had been told that to increase ROD you increased speed. Speed brakes had not featured in the education. Surely they are there for more than lift-dumping on landing & RTO's? They are a tool to be used as required.
What really did astound me was how many gung-ho top gun wannabes asked for >250kts below FL10 only to use speed brakes downwind as they struggled to slow down to min clean speed or called for flaps at max flap speed trying to remove the excess energy they had imparted to the a/c. Lessons slowly learnt.
B757/767. High downwind under radar home base, but could always expect a short turn in if ATC perceived it OK, and if a heavy was out on long finals. You are at minimum clean speed, 210kts. ATC gives a large descent change of altitude from FL 70 - 2000' which is a clue. Choices? Extend Spd Bks and keep speed 210kts? Select flap 1, 210kts, speed brake etc. etc. or as many newbies did, select 250kts. They had been told that to increase ROD you increased speed. Speed brakes had not featured in the education. Surely they are there for more than lift-dumping on landing & RTO's? They are a tool to be used as required.
What really did astound me was how many gung-ho top gun wannabes asked for >250kts below FL10 only to use speed brakes downwind as they struggled to slow down to min clean speed or called for flaps at max flap speed trying to remove the excess energy they had imparted to the a/c. Lessons slowly learnt.
Last edited by RAT 5; 19th May 2016 at 08:36.
Joined: Mar 1999
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From: on the road less travelled
Select flap 1, 210kts, speed brake & V/S 1000fpm
In your scenario SPD BRK and V/S -1000 will work against each other. A/T in SPD mode (Boeing) to maintain V/S. FL CH and full boards if well above profile.
