777 spoiler deployment on lamding

[JammedStab]

Quite interesting spoiler deployment on the 777 on landing. Four spoilers(2&5 on left wing, 10&13 on right wing) are completely inhibited from deployment on initial touchdown. As well, the inboard group(or at least some of them) are limited to partial initial deployment. Following a certain minimum time and reduction of AOA, the spoilers that did not deploy or only partially deployed, extend fully.

Also note that the flaperon retracts automatically as well on touchdown.

https://www.youtube.com/watch?v=3_HIcbpzpZw

https://www.youtube.com/watch?v=QLn50RzTA18

[FCeng84]

The autospeedbrake sequencing is designed to accomplish a couple of objectives: minimize pitching moment disturbance and ease settling on the gear - particularly for low sink rate landings. If all of the spoilers were fully deployed together, the lift loss could turn a smooth landing into a rather objectionable final drop onto the runway.