At the end of it, when the A380 has landed and the flaps are retracted, you can see that the spoilers go up very slightly in the flap retraction process, and then down again when the flaps are completely retracted. Does anybody know if this exists on other planes too? And mostly, if this happens also at flap retraction in climb, would this affect lift much?
Which aircraft? I have never worked on an aircraft where the spoilers raise to let the flaps in. If the spoilers are slightly misrigged, they might be pushed up by the retracting flaps, but where is the input to raise them. Does the Flap control unit send a signal to the spoiler control units to raise the spoilers? Never heard of it. Well not on B744 B777 B767 B757 B737 A320 L1011.
I've never ever seen that in any aircraft I've flown on comercially and never heard of that being used in any other plane. Wouldn't be surprised if the A380 was the first airliner to have that feature.
OldAeroGuy From United States of America, joined Dec 2004, 3683 posts, RR: 66
Reply 8, posted (8 years 1 week 6 days ago) and read 12448 times:
It's a good indication that the flaps have a lot of Fowler motion, ie they move back a long ways before the trailing edge down rotation begins. In addition, this mechanization is probably also necessary as the A380 airfoil has a lot of aft camber, consistent with a supercritical section.
To the best of my knowledge, this is the first time this technique has been used on a large commercial aircraft.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
AA737-823 From United States of America, joined Mar 2000, 6091 posts, RR: 12
Reply 9, posted (8 years 1 week 5 days 23 hours ago) and read 12433 times:
Common in most aircraft?
I have flown many, many types, most of them multiple times, and I have never seen this in my life.
In fact, take the Boeings... you can typically see scrape marks on 737 and 757 flaps, where they have interfered with the spoilers...
Zeke From Hong Kong, joined Dec 2006, 9798 posts, RR: 75
Reply 10, posted (8 years 1 week 5 days 23 hours ago) and read 12416 times:
Quoting TristarSteve (Reply 4): Just watched the video. That is a programmed rise of the spoilers. Never seen it before.
Its a good idea because it allows for an airtight seal between the spoilers and the flaps in cruise.
I am thinking it maybe more for ice, if you retracted the flaps without raising the spoilers one could possibly damage the flaps, by raising them the damage is avoided.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
I too have never seen this before, like many others have stated here. I've flown on many 737's, A320's, A319's, a 767-300...DC-10...I've never seen the flaps extend slightly to let the flaps retract, so I'm confused where you've seen this before...
WSOY From , joined Dec 1969, posts, RR:
Reply 17, posted (8 years 1 week 5 days 2 hours ago) and read 11406 times:
This patent application might be of interest, the patent assignee is the builder/designer of the A380 spoilers. Written in almost inpenetrable patentese, if might benefit from a translation into practical English by the experts presently on the forum.
Miamiair From , joined Dec 1969, posts, RR:
Reply 18, posted (8 years 1 week 4 days 10 hours ago) and read 11249 times:
I've never seen that on any of the Boeings. Most spoilers have a phenolic rub strip at the aft end for that very purpose.
Below is a 747 spoiler. The rub strip (-61) is replaced at every overhaul. It is easier to replace a rub strip than to add a monkey-motion system to not rub the spoiler on the upper skin of the flaps. KISS.
WSOY From , joined Dec 1969, posts, RR:
Reply 19, posted (8 years 1 week 4 days 10 hours ago) and read 11244 times:
So to elaborate on my earlier posting, it seems to me the reason for the slight deployment of the spoilers on the A380 is to allow the by Patria patented vortex generators on the underside of the spoiler to enhance the lift of the flaps.
JetMech From Australia, joined Mar 2006, 2700 posts, RR: 53
Reply 24, posted (8 years 1 week 2 days 23 hours ago) and read 10945 times:
Quoting Miamiair (Reply 18): It is easier to replace a rub strip than to add a monkey-motion system to not rub the spoiler on the upper skin of the flaps. KISS
The again, "monkey motion" is not exactly hard to arrange for with a FBW flight control system. In a certain way, a FBW flight control system is more in line with the KISS principle than the hydro-mechanical flight control system of the 747.
JetMech split the back of his pants. He can feel the wind in his hair.