plane bobbing up and down

hi guys,
can anybody give me some advice - on some planes (currently 777-300er) my plane starts to bob up and down while on autopilot and reducing speed/altitute… got a screenshot in case the flaps or speed or weather etc are influencing this or is there something im doing wrong?

also sometimes ill be cruising and the plane will be slightly pitched up. ive come across a thread regarding trim but trimming up or down doesn’t seem to do much

cheers

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You are most likely too heavy or flying too fast.

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It looks like your going a good speed so I dont know why it would be bouncing up and down unless you are changing altitudes from like 8000 back to 9000 quickly

Looks like your flaps are still down. Try putting the flaps up and see what happens. I would start activating flaps when you are close to being on final to your runway

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I also checked, to the right, at 9000 feet you flaps and spoilers should be up.

You also may want to try to increase your airspeed. I have seen this before when around 200kts higher up.

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ive had a look and im well within the MLW. i don’t think im too fast for the altitude im at. i was flying at 240 knots for a while and it was fine. it happened when i reduced my speed.

sorry i tried to quote all your comments but i don’t think that worked out as planned!

i was flying at 9000 for quite a while before this happened. i was advised not to exceed 210 knots by atc, when i reduced speed the bobbing started. could it be because im going too slow although thats the max i was instructed to fly?

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can i clarify what you mean?, sorry. flaps up as in they should be on 0? and spoilers up as in on flight or off? i don’t think theres much difference between off and armed - only when the plane touches down the spoilers will deploy? (correct me if im wrong)

i tried reducing the flaps all the way to 0 but nothing changed, the plane was still bobbing up and down

210kts was the max i was advised by atc to fly unfortunately.

If it happened when slowing down, then you’re probably too heavy and you need to dump fuel.

You can tell ATC unable which means that you cant go that slow… but you must have had to much fuel on board to be too heavy for that

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Agree. If you can’t go that slow then reply with unable. When given a speed restriction it usually means that you are following someone and they want you to maintain spacing.

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i was well within the MLW, the fuel dump option wasn’t available as i was within the MLW also

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i do think it was the fact i was going too slow, and the a/p kept increasing power to try maintain my altitude hence the plane was bobbing up and down. are ATC aware of this kind of stuff? the last time i responded unable i was told to follow instructions!

also can i just get a clarification, are my spoiler and flap settings ok?

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Yeah your probaly correct in that you were too heavy for speed so the A/P keep trying to correct it so it was moving a lot. ATC is not aware of this as approach normal cant ser the airplanes. I would just circle around for a while then land when lower on fuel and weight

@n587kk At AGL 090, you should have no spoilers and 0* flaps.

Yes, the flaps should be on zero. When descending, use spoilers in the “flight” option to slow down. When you’re at least 6000-5000 feet, then you could start lowering your flaps.