Flight spoiler purpose

[Liufeng]

Hello Internet aviation gurus,

I am presently sitting a type rating course for a FBW aircraft. The course material talks about the multi-purpose flight spoiler by mentioning that the purpose is to (1) Enhance roll control, (2) Reduce airspeed and (3) airbrake.

My question is what ever can be the difference between (2) and (3)???

Please speculate and enjoy trying to understand my english.

[Lord Spandex Masher]

At a guess I'd say their nebulousness means maintaining airspeed and using the air brake/spoilers to increase ROD.

[Intruder]

They are the same, as you describe.

In reality, you can use them to either slow down, or prevent acceleration, or increase rate of descent, or some combination. The end result depends on the pitch input you provide along with their use.

FBW has nothing to do with it.

[Firestorm]

In the air the airbrake can increase the rate of descent for a given airspeed, or assist in slowing the aeroplane while in level flight. On the ground the speedbrake (the same bits, but different purpose now) reduce the lift produced by the wing, thereby putting more weight in the wheels, thereby squashing the tyres, increasing the contact area of rubber on tarmac, thus increasing the effectiveness of the brakes. I have heard quoted that speedbrakes (or spoilers) increase the effectiveness of the brakes during the roll out by up to 30 per cent.

[captjns]

ATC mistake. Never poor descent planning.

[misd-agin]

Asymmetrical deployment for roll.

Symmetrical deployment in flight for drag(reduce airspeed of increase rate of descent).

Symmetrical deployment on ground. Increase brake effectiveness by increasing weight on wheels but also has a drag effect.