Just saw that the A359ULR will have an inactive forward cargo hold. https://www.flightglobal.com/news/artic ... ld-449495/

This makes sense for ULR ops given the payload restrictions. OTOH it limits the frame's usefulness if "misused" on shorter hops. With a super-low-density configuration, however, short hop misuse is perhaps so far suboptimal that it mightn't have been planned.

A few questions:

• What is the weight saving from omitting the forward cargo loading infrastructure? Does that infrastructure typically include integral pullies/rams for moving boxes or is that equipment loaded/unloaded at gates?
• Do we think - or does anyone know - that the ULR will lack cargo hold floor beams? Or would that present too much of an obstacle to paper recertification from ULR to standard? What would the weight implication of losing cargo floor beams be? I've read that pax floor beams are ~5 lbs/ft2; I could see cargo beams being more (due to higher density) or less (due to no 16g survivability requirement).
• Placing all luggage in the rear hold means an aft-heavy weight distribution at full ULR load (173 pax). Combined with J/Y fore/aft layout, the effect increases. I guess I'm wondering what scope airliners typically have for balance/stability. Is this only possible due to A350's cruise camber modification capabilities?

If you read the article carefully, your first 2 questions are essentially answered. From Flight Global "The A350-900ULR can be ‘reversed’ into a standard -900 if the airline decides. From an airframe perspective it is ‘paperwork’ and you need to re-activate the forward cargo hold…and install the cargo-loading system.". So, the infrastructure (floor beams and assorted structures) will be there but the cargo loading system will not be installed on the ULR. The CLS is a motorized system which moves the containers.

Regarding the loading, there will be an aft C/G but remember the J seats are substantially heavier than the Y+ seats so the load should be optimized for the type of flying the ULR was designed to do.

mmo wrote:

So, the infrastructure (floor beams and assorted structures) will be there but the cargo loading system will not be installed on the ULR. The CLS is a motorized system which moves the containers.

The article doesn't specify which of the cargo infrastructure is missing on the ULR. There is no specific mention of beams versus pulleys/presses/rollers.

I doubt whether it is possible to build a plane without cargo beams that can be readily converted for cargo use. That's why I ask. I could see the beams being too integral to the structure and/or too expensive or impossible to retrofit. It would be cool from an efficiency perspective if beams are missing and installable later, however.

EDIT: Ok I see your point better: the specific mention of CLS as missing implies everything else is not missing. That's probably the best reading of the text.

Just as a theoretical point - suppose customers were at some point sufficiently confident in the ULH model to buy the ULR without possibility of cheapish conversion to standard. Could we take out the cargo beams then? And how much do they weigh?

Matt6461 wrote:

mmo wrote:

So, the infrastructure (floor beams and assorted structures) will be there but the cargo loading system will not be installed on the ULR. The CLS is a motorized system which moves the containers.

The article doesn't specify which of the cargo infrastructure is missing on the ULR. There is no specific mention of beams versus pulleys/presses/rollers.

I doubt whether it is possible to build a plane without cargo beams that can be readily converted for cargo use. That's why I ask. I could see the beams being too integral to the structure and/or too expensive or impossible to retrofit. It would be cool from an efficiency perspective if beams are missing and installable later, however.

EDIT: Ok I see your point better: the specific mention of CLS as missing implies everything else is not missing. That's probably the best reading of the text.

Just as a theoretical point - suppose customers were at some point sufficiently confident in the ULH model to buy the ULR without possibility of cheapish conversion to standard. Could we take out the cargo beams then? And how much do they weigh?

If Airbus / the airlines would like to create a dedicated ULH machine, many further options would be open the use the forward cargo area in a different way, for sleeping / crew / fuel / lavatory. Also the higher MTOW -1000 wings, engines, landing gear, center section could be used.
https://farm5.staticflickr.com/4118/35684936976_e72b313591_b.jpg

However the strenght of the LR solution seems to be simplicity & risk reduction, so highly unlike they will move away from that.

keesje wrote:

https://farm5.staticflickr.com/4118/35684936976_e72b313591_b.jpg

149t OEW assumed.
What is the estimation on the A350ULR OEW? 130..2.. something ?

WIederling wrote:

keesje wrote:

https://farm5.staticflickr.com/4118/35684936976_e72b313591_b.jpg

149t OEW assumed.
What is the estimation on the A350ULR OEW? 130..2.. something ?

Significant highter than A359. The 3 bogey landing gear, heavier engines, pylons, overall structure.
I could distract the meters fuselage from an A350-1000, but don't have time..

keesje wrote:

WIederling wrote:

keesje wrote:

https://farm5.staticflickr.com/4118/35684936976_e72b313591_b.jpg

149t OEW assumed.
What is the estimation on the A350ULR OEW? 130..2.. something ?

Significant highter than A359. The 3 bogey landing gear, heavier engines, pylons, overall structure.
I could distract the meters fuselage from an A350-1000, but don't have time..

"estimated OEW" not for the Big Foot ULR ( that is projected in the image link :: 149t ) but
for the nimble en pointe ULR based on the regular A350-900 with 280t MTOW, more tankage ...

Has to be less than 149 tonnes, as the empty weight of our 35Ks is below 150 tonnes, assume the same wing, gear, engines as the 35K and take out 35Ks fuselage frames.

If I remember correctly the aft fuselage frames were quoted in flight global to have a mass of around 2500 kg.

Obviously the savings with deactivating the forward hold are mainly structural with the loading system, there would be a change with the fire protection, electrical, and environmental control systems.

zeke wrote:

Has to be less than 149 tonnes, as the empty weight of our 35Ks is below 150 tonnes, assume the same wing, gear, engines as the 35K and take out 35Ks fuselage frames.

If I remember correctly the aft fuselage frames were quoted in flight global to have a mass of around 2500 kg.

Obviously the savings with deactivating the forward hold are mainly structural with the loading system, there would be a change with the fire protection, electrical, and environmental control systems.

Any idea how much of an engineering challenge is it to get the 6 wheel mlg into the present 900 wing? I am thinking perhaps a solution exists for a ~290ton mtow for the Qantas requirement without going the whole hog with the trailing edge extensions. The engine will have to get a thrust bump I guess.

I don’t think that would be viable for the small market size, two wings is already enough. The difference between the 4 and 6 frame MLG bay is enough, you also need the means to get the loads in and out of the wing into the gear and fuselage. Work for which they have already done.

It would be cheaper to do what they did on the A320 and put more smaller tyres on the same MLG than to make structural changes to the wing.

Keesje wrote:

Significant highter than A359. The 3 bogey landing gear, heavier engines, pylons, overall structure.
I could distract the meters fuselage from an A350-1000, but don't have time..

Zeke wrote:

assume the same wing, gear, engines as the 35K and take out 35Ks fuselage frames.

A350R's wing would be lighter than A35K's due to lower MZFW bending moment, though increased fuel load in wings would ameliorate the delta.
Plus we can't be sure that the original -R concept would have had sufficient tail volume if you tacked on TXWB-97's, given the shorter lever arm for OEI yaw and rotation. Good chance you'd need a bigger empennage.

Interesting approach to trimming weight


While this may add a little range it will limit the utility and flexibility of the aircraft


Unless they confine it’s use to purely ULH
operators won’t be able to use its full cargo
capability on regional routes between the long hauls as many carriers like to do

They may not need to have them flying regionally, if every long haul flight is already 16+ hrs the utilisation is already highly. The aircraft will still need time to be maintained, cleaning, catering, and boarding.

They won’t need shorter flights for their crew to maintain currency as they have other A350s.