A330 Weight & Balance when lightly loaded
 

Just flew back o/night from US East Coast to UK as SLF on an A330 with a moderate load factor, but a long way from empty. Intrigued that pax were redistributed in cattle class for departure, but then allowed to return to original seats after take off. Pax bunched up to rear of cabin for departure.
No personal experience of arranging aircraft loading for that a/c type or on that route, back in the day I'd have just moved freight or baggage aft.
Would be interested in summary points from experience as to why the faff of trying to herd cats by reseating pax (and we had a non-stop stream of PAs from the ground team as we sat in the pens awaiting boarding) was a better solution than just moving underfloor loads.
Thanks!

Rear hold out of use?

Don’t know about the A330 but a VS pilot says the A350 needs 5000kgs rear ballast when flying empty or lightly loaded. A problem due to the weight of the new Upper Class furniture apparently.

I do not know how many A330s fly from East Coast to UK but is there any chance it was wet leased Evelop flying for BA? It is already some time since I prepared A330 and it is really long time since I prepared empty A330 but if I remember correctly A330 has problem to fly empty because without load you are out of trim or almost out of trim.
As far as I know certain A330s and A340s flying from US to Europe they are simple to load but they can get tricky when you have few PAX on board. Then we had problems all the time with those birds. It really depends what was loaded in holds.
Typical scenario during winter for us was full first class, business and some people in economy. This makes you nose heavy. Then it depends what load you have. If you have just bags it may not be enough. If you have cargo it may help you or it can make things even worse. Why? Many light pallets do not help you in the aft so they go to forward making it even worse. Heavy pallets. Great, they can go to aft. Well, they could but you will not lock them there unless they prepared specific combination. Another thing which can mess it up are all the limitations for dangerous goods and special loads and sometimes locks were problems so you really could not load things freely. It happened to me few times that I had to move some PAX in economy to very aft. And by few I mean few rows. Well, many rows. Poor people were siting at toilets in aft galley just so I could let them fly with trim just on front limit.

That is true. I will be at work tomorrow so I will check it for you but if I remember that correctly there is crazy fuel vector for A350. Even when you are fine on ZFW you will be way out of trim on TOW with fuel because trim jumps forward. We still have A350 in testing so I do not prepare them (waiting for my training in Dec) but as far as I know they were carrying crazy amounts of empty AKE in the aft.

Flew on a 747-400 with full pax load on a sight seeing venture so there was no baggage and ballast had to be loaded in the under floor hold. Which end don't know or how much.

So I checked that for you.
A330-300 when empty is just on forward limit. Fuel moves you a bit more FWD and above 35 tons it moves trim to AFT. So index on TOW is ok but on you may have problems on ZFW.
And as I said PAX and cargo really depends what you have. If you have more specific question feel free to ask.

I was curious about mentioned 747-400. I tried that and full of PAX, no load, it was well within limits. I would say it is configuration problem.

I check documents for A350-1000 and few flights for A350-900. As empty is it hopeless. No way it can fly without some weight in the aft. It is quite fine for normal flights, nose heavy but fine. Passengers do a lot in the aft and cargo too if you have any. I would say it is because that aircraft is so long. For TOW limit fuel helps you if you have up to 48 tons. Fuel up to 66 tons makes no change to trim and everything above makes everything horrible. For long flights you end up in a corner of envelope for MTOW and FWD trim index.

If you need some examples or so let me know. I will make you flight with your numbers.

I can only speak for 747 Classic, -100 and -200, but a full 747 and no bags and alot of fuel will send the trim way forward - so any ballast would have gone in the aft.

Megan - Are you referring to the Qantas 747 Antarctica 13 hour scenic flights down to the South Pole?
I always wondered how they dealt with those for planning and dispatch. I have fancied doing a flight on one myself to see the Ice.

That is true even for B744 if you do not have or use tail tank. I did not expect for such a flight to have so much fuel. But the envelope is really wide when you are heavy. Or maybe not that wide as extended to forward. I do not know how to describe that.

I just ferried an empty A350-1000 the other day.
We didn't need ballast.
MACZFW 23.31
MACTOW 26.31

I found a special envelope for ferry flights, approved....

cool thanks - what was the sector?

Thanks for all above - has helped me understand some more about what happened. From the comments so far it seems that moving economy pax was the best thing to do.
@Rarife - no, not an Envelop aircraft.

That's affirmative rog, a wonderful day out, departure about 0800 local and return about 2100, out of Melbourne as a pax, no idea of planning details.

I do not know SQ but as far as I know and what have I seen I'm pretty sure that is the problem.
I did not take a manual or any pictures of real flghts so it very illustrational just from what I remember. I found the envelope on the Internet and I would say that real one in more limited but the shape is correct. Especialy in FWD where it is most important for our case.
I made the green line which is fuel vector. You are at ZFW which is fine but once you take a lot of fuel it moves a bit AFT but then more and more fuel moves the CG very FWD and you hit the corner there. That is how one A350-900 flight looked yesterday. PAX almost full, cargo and bags loaded in AFT (it was full) and FWD hold was loaded too. Few rows for ULDs in FWD were empty. Not because they had to but they had nothing more to load.
But there are no doubts that more than weight you will have trim problems on this aircraft. When you take a lot of fuel you really have to be tail heavy at zero fuel weight.
https://cimg2.ibsrv.net/gimg/pprune....9f0336b724.png

yes and I just ferried an A350-1000 empty and we didn’t have any issues either using the special “ferry flight” Envelope.......Wouldn't have worked with the normal Revenue Envelope.

The QF Antarctic charter always takes 5 ton ballast in the forward hold.