737 takeoff

[pilot_2b]

hi.
i have just had a flight on a 737 - 300 and just after lift off from the runway the speed breaks were deployed. they were only deployed very slightly but i was confused as to why this happened. could anybody tell me why this occured??
cheers

[The Big Bad Daddy]

You saw the spoilers raise slightly on that wing to assist the ailerons to roll the aircraft, this happens when a certain amount of input to the left or right is made on the controls.

[Notso Fantastic]

......and the spoilers, combined with an extra panel, magically become 'speedbrakes' after landing! They would deploy inflight if fairly generous inputs were being applied by the pilot.

[pilot_2b]

hey thanks for the replies. i have one more question really on this topic. why do the ailerons need assistance in rolling the aircraft. cheers again

[Maximum]

In simple terms they are more effective for swept-wing aircraft than ailerons alone. They are more effective at high speed as they cause less wing twisting. They also cause the aircraft to yaw in the direction of the turn, whereas ailerons alone cause adverse yaw contrary to the direction of roll.

[HugoFirst]

. . . it also means you don't have to have really large ailerons and as Maximum says, it helps in the turn. The spoilers/speedbakes are already there . . . may as well use them.

[Notso Fantastic]

Bet you don't know this: on the 747, there are outboard ailerons, and inboard ailerons at the back of the wing directly behind the inboard engines (spare space as you can't have flaps directly behind the engines- spoils their fatigue life!). When the flaps have retracted, the outboard ailerons are disconnected and no longer work until the flaps extend again. The inboard ailerons only provide roll control, again assisted by the spoilers when the control wheel is moved past a certain angle.