777-300ER Cruising Problems

Hello all!

Coming back to this topic:
When I fly the 777-300ER, it can’t stabilize the aircraft at cruising altitude.

I’m stepclimbing, not going too slow or too fast (M.84), my ascent rate wasn’t too high and I’m not too heavy
My plane is going up to (-)700 fpm and back down, it just can’t hold it’s current altitude

I’m sure that many of you have the same problem.
Also note: this only happens on the 300ER variant.



Has happened to me a few times before, and there are multiple support threads about this exact issue. And also I believe Staff is aware of this, not sure but if I do recall correctly, I remember Schyllberg talking about them trying to reproduce this issue before.

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It happens to me every time, yes I was wondering if they are aware of it.

I’ve never had this issue but is there any odd wind?

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It’s safest to wait til they reply with their answer but I do feel like I’ve read somewhere where Seb was talking about reproducing this issue.

Other than that, this happens to me, very, very rarely, but it does. I who flies Long Hauls only on a daily basis have faced this before and weight doesn’t seem to be the cause entirely.

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I have 40kts tailwind now, but it happens with 5 kts or even 2 kts aswell.

It then sounds like a odd glitch maybe with the physics.

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That’s very weird, are you sure that you’re talking about the 300ER variant?

But well, let’s wait for an update.

I’ve noticed that when it does happen, it’s most often because of the plane to heavy and you’re too high up, but when I descended, the plane kept going up and down…

But a little less. Only that I stepclimed as you’re supposed but it would still go up and down but by 300ft, not 700 like yours, which seems like to be too extreme.

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It’s the ER variant, that I fly the most of the time, so that’s where I’ve encountered this issue a few times. But I just like you have never faced this on the 200 variants.

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Yeah, it’s the first time that I’m experiencing 700 feet drops. It’s normally around 200fpm.
I’m at FL350 with 80% load and correctly trimmed.

I’ve been at FL330 with 60% and had that issue, so weight isn’t the only factor here, neither is winds.

But they do make the problem worse, that is to be too heavy and too high.

But as I said, I don’t experience this that often, maybe 3 times a month, of the 20 B777 flights I do every 30 days so, it’s quite rare in my opinion.

Just like I’ve never experienced any issues with the A321 which others have, this one is very uncommon for me, Rare is what I’ll use to say instead. Chance of this happening to me is slim. Last time I had this problem was 2 weeks ago, but it fixed it self after 4hrs into the flight, oddly enough…

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I’d for no suggest you to descend to FL330 and see if that makes matters better. Weight does play the biggest role as far as I’m concerned, as of now at least so try and see if flying at a lower ALT will help.

Although you should be fine at FL350 with 80%, but still, maybe going a bit lower might reduce issue.

Happened to me too on an Etihad trip to Hawaii

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I’ve descended to FL330 and there are drops of 600fpm now, so a bit less but still.

It happens to me every time which takes the fun away from flying this plane.
I’m using 787’s now for ultra long hauls and they’re awesome.

Thanks for your help!
A mod may now close this topic and I hope that someone will take care of it

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When this happens, to stabilize, just disable auto-ALT and set V/S to 0. Regardless of your speed nor weight, your plane will come to stabilize.

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