FBU 4EVER! From Norway, joined Jan 2001, 998 posts, RR: 6
Reply 3, posted (14 years 7 months 4 days 5 hours ago) and read 1680 times:
In addition to JETPILOT's reply,which is valid for planes with hydraulically operated flight controls,there are other ways to tell,as well:
On the DC-9 and MD-80/90 series with manual flight controls,a "SPOILER DEPLOYED" light will appear on the Annunciator panel when the ailerons are tested.Elevators have no indication except for a green "ELEVATOR POWER" light which comes on when the control column is pushed fully forward (nose down) indicating that the Stall Recovery Augmentation System is working.
The MD-90 has a fully hydraulically operated elevator,and full forward and aft motion of the control column will activate an "ELEVATOR AT LIMIT" sign.
The checs are mainly performed to check that the controls move freely without obstructions.
M80 From Finland, joined Mar 2001, 36 posts, RR: 0
Reply 4, posted (14 years 7 months 4 days 1 hour ago) and read 1675 times:
A very small correction to FBU 4EVER!'s good explanation: DC-9/MD-80 annunciator panel has no green lights: advisory lights are blue, for example ELEVATOR POWER ON, IGNITERS ON and ANTI-ICE lights. (Caution lights are amber and warning lights are red.) And some additional info for DC-9/MD-80: Spoiler deployment starts when control column is moved 5 degrees from its neutral position, spoilers remain retracted with down aileron. Also the elevator power test (DC-9/MD-80) aligns the elevator surfaces (normally performed before takeoff to make sure that there are not any control column forces affecting takeoff.)
Apuneger From Belgium, joined Sep 2000, 3033 posts, RR: 10
Reply 6, posted (14 years 7 months 2 days 19 hours ago) and read 1631 times:
Thx for all the answers, guys...
But, as already mentioned, I saw the FO looking out of the window, to the back of the plane, when he was testing his control surfaces. The plane was a Boeing 737-329. Does this mean that he could still see the (end of) the wing, and preferred to see (some of) the surfaces work visually, instead of looking to some anunciators.?