I guess the visual aspect is interesting, having aircraft look at its surroundings, processing the information and acting upon it. Next to the more regular available situational awareness (GPS, height, speed, ATC, weight, wind, tempearature, airport maps, etc.) . Automotive have been doing groundwork here.

Isabelle Lacaze, head of the DragonFly demonstrator at Airbus UpNext said, “These tests are one of several steps in the methodical research of technologies to further enhance operations and improve safety. “Inspired by biomimicry, the systems being tested have been designed to identify features in the landscape that enable an aircraft to ‘see’ and safely maneuver autonomously within its surroundings, in the same way that dragonflies are known to have the ability to recognize landmarks.”

source: https://www.aerospacetestinginternation ... -a350.html

Someone here asked here whether the 6 odd A359ULR's be converted back to standard A359's, the answer here is yes. The ULR is not a seperate aircraft variant but rather a special mod of the standard 280t A359 which seals the cargo bay (Mods 110456/110512) and increases fuel capacity through Mod 110211.

moyangmm wrote:

There still no evidence that these 350 on LAX-SIN can operating at full pax capacity though (i.e., no seat blocked, full 253 pax plus luggages). As you said, when cargo is more lucrative, maybe they are trading pax weight for cargo weight.

There is evidence.

viewtopic.php?t=1405913&start=60 SQ estimates for using 101.4t of fuel and 10.1t of reserves.The relevant V speeds suggest TOW of ~273t and so a landing weight of 172t.

Knowing that 150pax weigh ~15t then we can deduce that the aircraft without fuel or pax would be approximately 147t.

viewtopic.php?t=1447519

in this thread in reply 7 you can see a representative A350 with a DOW of ~135t

This suggests that the SQ flight was also taking ~10t of additional payload.

In any case we can see that the Breguet range factor for the aforementioned 8285nm flight ((UL/D)/TSFC)) would be ~17933 .....(Mission_Range/(LN(TOW/LW)).

If we apply this same range factor to a 7621nm flight (LAX-SIN) then we can see that with an MTOW takeoff we would achieve a landing weight of 183t.

If we take away 10t of reserve fuel (assuming that SQ are this conservative on all flights, not just the first time operating the worlds longest flight in some years) we get 173t. If we then remove the 25.3t of pax weight (100kg each)we then have a weight without pax of 147.7t, this leaves plenty of room for cargo.

Lets build it up the other way however.

Assume there is full pax (253) added to the aircraft along with 5t of reserves and 5t of pantry (135.5+5+5+25.3) gives 170.8t. Assuming it takes off at MTOW (280t) then using the same Breguet Range factor it will have an SAR of 8864nm. For this aircraft to be in jeopardy of not making it with a full pax load it then has to encounter average headwinds in the order of 68kts...

If by evidence you mean you want to see a load sheet then I'm afraid I am of the same opinion regarding there being no evidence to suggest that the B787-10 can take a full pax load from LHR to MCO....

fRED

swapcv wrote:

Someone here asked here whether the 6 odd A359ULR's be converted back to standard A359's, the answer here is yes.

There's 7 of them (for SQ, plus 2 more for the German government) and Airbus has advertised since their launch that they can be converted back to standard. No real revelation there.

flipdewaf wrote:

moyangmm wrote:

There still no evidence that these 350 on LAX-SIN can operating at full pax capacity though (i.e., no seat blocked, full 253 pax plus luggages). As you said, when cargo is more lucrative, maybe they are trading pax weight for cargo weight.

There is evidence.

viewtopic.php?t=1405913&start=60 SQ estimates for using 101.4t of fuel and 10.1t of reserves.The relevant V speeds suggest TOW of ~273t and so a landing weight of 172t.

Knowing that 150pax weigh ~15t then we can deduce that the aircraft without fuel or pax would be approximately 147t.

viewtopic.php?t=1447519

in this thread in reply 7 you can see a representative A350 with a DOW of ~135t

This suggests that the SQ flight was also taking ~10t of additional payload.

In any case we can see that the Breguet range factor for the aforementioned 8285nm flight ((UL/D)/TSFC)) would be ~17933 .....(Mission_Range/(LN(TOW/LW)).

If we apply this same range factor to a 7621nm flight (LAX-SIN) then we can see that with an MTOW takeoff we would achieve a landing weight of 183t.

If we take away 10t of reserve fuel (assuming that SQ are this conservative on all flights, not just the first time operating the worlds longest flight in some years) we get 173t. If we then remove the 25.3t of pax weight (100kg each)we then have a weight without pax of 147.7t, this leaves plenty of room for cargo.

Lets build it up the other way however.

Assume there is full pax (253) added to the aircraft along with 5t of reserves and 5t of pantry (135.5+5+5+25.3) gives 170.8t. Assuming it takes off at MTOW (280t) then using the same Breguet Range factor it will have an SAR of 8864nm. For this aircraft to be in jeopardy of not making it with a full pax load it then has to encounter average headwinds in the order of 68kts...

If by evidence you mean you want to see a load sheet then I'm afraid I am of the same opinion regarding there being no evidence to suggest that the B787-10 can take a full pax load from LHR to MCO....

fRED

I've been following the A.net forums for like 20 years (only got around registering) and it's seriously entertaining to read how that person underestimates the A359. It might as well have not enough range to leave France.

Delaxio wrote:

flipdewaf wrote:

moyangmm wrote:

There still no evidence that these 350 on LAX-SIN can operating at full pax capacity though (i.e., no seat blocked, full 253 pax plus luggages). As you said, when cargo is more lucrative, maybe they are trading pax weight for cargo weight.

There is evidence.

viewtopic.php?t=1405913&start=60 SQ estimates for using 101.4t of fuel and 10.1t of reserves.The relevant V speeds suggest TOW of ~273t and so a landing weight of 172t.

Knowing that 150pax weigh ~15t then we can deduce that the aircraft without fuel or pax would be approximately 147t.

viewtopic.php?t=1447519

in this thread in reply 7 you can see a representative A350 with a DOW of ~135t

This suggests that the SQ flight was also taking ~10t of additional payload.

In any case we can see that the Breguet range factor for the aforementioned 8285nm flight ((UL/D)/TSFC)) would be ~17933 .....(Mission_Range/(LN(TOW/LW)).

If we apply this same range factor to a 7621nm flight (LAX-SIN) then we can see that with an MTOW takeoff we would achieve a landing weight of 183t.

If we take away 10t of reserve fuel (assuming that SQ are this conservative on all flights, not just the first time operating the worlds longest flight in some years) we get 173t. If we then remove the 25.3t of pax weight (100kg each)we then have a weight without pax of 147.7t, this leaves plenty of room for cargo.

Lets build it up the other way however.

Assume there is full pax (253) added to the aircraft along with 5t of reserves and 5t of pantry (135.5+5+5+25.3) gives 170.8t. Assuming it takes off at MTOW (280t) then using the same Breguet Range factor it will have an SAR of 8864nm. For this aircraft to be in jeopardy of not making it with a full pax load it then has to encounter average headwinds in the order of 68kts...

If by evidence you mean you want to see a load sheet then I'm afraid I am of the same opinion regarding there being no evidence to suggest that the B787-10 can take a full pax load from LHR to MCO....

fRED

I've been following the A.net forums for like 20 years (only got around registering) and it's seriously entertaining to read how that person underestimates the A359. It might as well have not enough range to leave France.

I have seen a few others that have exactly the same opinion. The only strange thing is they only seem to arrive to post their opinions on the matter at the exact same time and then sporadically disappear at the same time. It is a very weird coincidence...

Fred

Delaxio wrote:

flipdewaf wrote:

moyangmm wrote:

There still no evidence that these 350 on LAX-SIN can operating at full pax capacity though (i.e., no seat blocked, full 253 pax plus luggages). As you said, when cargo is more lucrative, maybe they are trading pax weight for cargo weight.

There is evidence.

viewtopic.php?t=1405913&start=60 SQ estimates for using 101.4t of fuel and 10.1t of reserves.The relevant V speeds suggest TOW of ~273t and so a landing weight of 172t.

Knowing that 150pax weigh ~15t then we can deduce that the aircraft without fuel or pax would be approximately 147t.

viewtopic.php?t=1447519

in this thread in reply 7 you can see a representative A350 with a DOW of ~135t

This suggests that the SQ flight was also taking ~10t of additional payload.

In any case we can see that the Breguet range factor for the aforementioned 8285nm flight ((UL/D)/TSFC)) would be ~17933 .....(Mission_Range/(LN(TOW/LW)).

If we apply this same range factor to a 7621nm flight (LAX-SIN) then we can see that with an MTOW takeoff we would achieve a landing weight of 183t.

If we take away 10t of reserve fuel (assuming that SQ are this conservative on all flights, not just the first time operating the worlds longest flight in some years) we get 173t. If we then remove the 25.3t of pax weight (100kg each)we then have a weight without pax of 147.7t, this leaves plenty of room for cargo.

Lets build it up the other way however.

Assume there is full pax (253) added to the aircraft along with 5t of reserves and 5t of pantry (135.5+5+5+25.3) gives 170.8t. Assuming it takes off at MTOW (280t) then using the same Breguet Range factor it will have an SAR of 8864nm. For this aircraft to be in jeopardy of not making it with a full pax load it then has to encounter average headwinds in the order of 68kts...

If by evidence you mean you want to see a load sheet then I'm afraid I am of the same opinion regarding there being no evidence to suggest that the B787-10 can take a full pax load from LHR to MCO....

fRED

I've been following the A.net forums for like 20 years (only got around registering) and it's seriously entertaining to read how that person underestimates the A359. It might as well have not enough range to leave France.

Indeed, I’ve head that Air France’s A350s have to wait for favourable weather conditions in order to be able to make the delivery flight from Toulouse to Paris non-stop!

LAX772LR wrote:

airbazar wrote:

A 253 seat A359 can't fly SIN-NYC with any meaningful payload either. The one they operated during the pandemic wasn't carrying many passengers.

Not exactly.

When they opped that route with the standard bird, they only did so with ships 9V-SMV, -SMW, -SMY, -SMZ, and -SJA; all of which feature the same 280tonne MTOWs and aerodynamic enhancements as the -ULRs, and selling out the J and W classes, while only selling full-Y fares, but still getting quite a few pax.

The difference being that those aircraft offered forward cargo hold capacity (whereas the -ULRs, ships 9V-SG*, do not) and they were filled, at least in bulk, to that effect.

My understanding is that those flights were mostly empty. Not hard to believe considering Singapore had severe travel and quarantine restrictions at the time.We also don't know what cargo they were carrying. Was it boxes of surgical masks? Surely it wasn't fish because only the 757 can carry that
If they could sell that many seats on a standard A359, plus cargo there would be no business case to switch back to the ULR bird, I don't think or they could have added frequencies like they did for LAX.

Also, ORD and LAS were served before but not from SIN. They were served from AMS and Seoul-GMP, IIRC. These ULH flights need large numbers of premium O&D passengers and I suspect that outside of NYC and California those numbers aren't there.

JerseyFlyer wrote:

I can see SQ replacing the ULR 359s with Sunrise 3510s, then converting the ULRs back to standard 359 frames

IMO that would make sense only if they didn't have a huge order of 779's already.

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

LAX772LR wrote:

No real revelation there.

I'm aware of that, you're aware of that, but the person who asked previously did not, so there's that. Hence the need for clarification and shining a bit of light on the same.

Delaxio wrote:

I've been following the A.net forums for like 20 years (only got around registering) and it's seriously entertaining to read how that person underestimates the A359. It might as well have not enough range to leave France.

Giving them the benefit of the doubt, I always believe they often base their assumptions off of outdated specs/charts from around 2014-15 based on the yet to enter service vanilla variant. In fact if you'd ask me what's special about the A350 in 2013-15, I'd be like, meh, just a bigger Dreamliner that's all, but as it stands today, the product has evolved and differentiated enough to have its own USP's. From what was essentially an aircraft aimed as a 777-200 replacement, it has done that and then some more by replacing even the 777-200LR and the A340-500 capability wise in its -900 iteration and the 777-300ER and A340-600 in its -1000 variant. And the best part about it, it seems that the airframe still has structural margins to go further without major design revisions.

airbazar wrote:

JerseyFlyer wrote:

I can see SQ replacing the ULR 359s with Sunrise 3510s, then converting the ULRs back to standard 359 frames

IMO that would make sense only if they didn't have a huge order of 779's already.

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

We can do the 779 can’t fly this route or that route if you like but this is an A350 thread.

Fred


Sent from my iPhone using Tapatalk

airbazar wrote:

If they could sell that many seats on a standard A359, plus cargo there would be no business case to switch back to the ULR bird

Not necessarily. Go back to the article I linked a few posts ago: their primary incentive for bringing back the -ULRs to NYC/SFO at the time that they did, was lack of any other available aircraft, by their own admission.

airbazar wrote:

Also, ORD and LAS were served before but not from SIN. They were served from AMS and Seoul-GMP, IIRC.

(1) LAS was served from HKG

(2) Hmm, remind us what passenger aircraft could've operated LAS-SIN and ORD-SIN nonstop, back in 2001....

This thread is off the rails, all I see is people complaining about what other users are saying.

LAX772LR wrote:

(2) Hmm, remind us what passenger aircraft could've operated LAS-SIN and ORD-SIN nonstop, back in 2001....

A340-313X

Back to the topic. Has any 283t build entered into service, since which MSN?

airbazar wrote:

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

moyangmm wrote:

airbazar wrote:

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

Nope, that assertion needs a bit more evidence me thinks. As you can see above, the analysis I provided shows that it is quite capable of flying 253 pax (8864nm is available at that pax load) You can choose to ignore if you like.

Fred


Sent from my iPhone using Tapatalk

flipdewaf wrote:

moyangmm wrote:

airbazar wrote:

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

Nope, as you can see above, the analysis I provided shows that it is quite capable of flying 253 pax (8864nm is available at that pax load) You can choose to ignore if you like.

Fred


Sent from my iPhone using Tapatalk

But then why SQ need to spend the extra money on their 7 ULR if they could just order normal A350? I assume the modifications of fuel system and front cargo door cost a non-trivial amount of money... Also, SQ is leaving potential revenue on the table by only install 161 seats, instead of 253. Something doesn't add up, no?

moyangmm wrote:

flipdewaf wrote:

moyangmm wrote:

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

Nope, as you can see above, the analysis I provided shows that it is quite capable of flying 253 pax (8864nm is available at that pax load) You can choose to ignore if you like.

Fred


Sent from my iPhone using Tapatalk

But then why SQ need to spend the extra money on their 7 ULR if they could just order normal A350? I assume the modifications of fuel system and front cargo door cost a non-trivial amount of money... Also, SQ is leaving potential revenue on the table by only install 161 seats, instead of 253. Something doesn't add up, no?

I have shown that it can.

You were the one that say it can’t.. show that it can’t. The fact that they don’t doesn’t mean it can’t.

Fred


Sent from my iPhone using Tapatalk

moyangmm wrote:

flipdewaf wrote:

moyangmm wrote:

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

Nope, as you can see above, the analysis I provided shows that it is quite capable of flying 253 pax (8864nm is available at that pax load) You can choose to ignore if you like.

Fred


Sent from my iPhone using Tapatalk

But then why SQ need to spend the extra money on their 7 ULR if they could just order normal A350? I assume the modifications of fuel system and front cargo door cost a non-trivial amount of money... Also, SQ is leaving potential revenue on the table by only install 161 seats, instead of 253. Something doesn't add up, no?

The ULR has the same forward cargo door as the other A359s I just believe the hold lacks all the cargo management equipment typically in place. I have wondered if the door has a lockout feature but I'm sure maintenance needs to have access periodically.

moyangmm wrote:

airbazar wrote:

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

In order to avoid a rehashing, it needs to not be brought up. It is you that has cast doubt on the claims (and now trying to gloss over the fact that you made this about LAX, not NYC). Will the A359 make NYC with full passenger load? I doubt this, but then someone like Fred would have to elaborate further. Assuming that the depth of their workings is not ignored. Again.

'I feel' is not a valid cause for such definitive claims.

moyangmm wrote:

airbazar wrote:

And do we really have to re-hash the "A359 can't fly this or that route" for the 300th time? My comment was specifically about SIN-NYC and nothing else.

I don't understand why they are rehashing this either. SIN-NYC obviously can only flown by A350-900ULR at designed passenger count (161). Those "regular" A350 flown during pandemic was a temporary measure when passenger demand is very weak. I feel it is bizarre to claim some airlines can haul 253 passengers from NYC to SIN with a 280t A359.

Then prove it. Do the math.

flipdewaf wrote:

Nope, that assertion needs a bit more evidence me thinks. As you can see above, the analysis I provided shows that it is quite capable of flying 253 pax (8864nm is available at that pax load) You can choose to ignore if you like.

With the Russian airspace avoidance, CX flew regular A350s from YYZ/JFK to HKG eastbound basically overflying LHR area then to HKG. With the distant city pairs, it really becomes a matter of endurance, the winds on the day can result in some very long ground distances being covered.

Flights from Asia to North America have shorter flight times as there is good tailwinds, I think HKG-LAX is sub 12 hrs at the moment.

keesje wrote:

I guess the visual aspect is interesting, having aircraft look at its surroundings, processing the information and acting upon it. Next to the more regular available situational awareness (GPS, height, speed, ATC, weight, wind, tempearature, airport maps, etc.) . Automotive have been doing groundwork here.

Isabelle Lacaze, head of the DragonFly demonstrator at Airbus UpNext said, “These tests are one of several steps in the methodical research of technologies to further enhance operations and improve safety. “Inspired by biomimicry, the systems being tested have been designed to identify features in the landscape that enable an aircraft to ‘see’ and safely maneuver autonomously within its surroundings, in the same way that dragonflies are known to have the ability to recognize landmarks.”

source: https://www.aerospacetestinginternation ... -a350.html

Wonder if one camera is IR, and the other time of flight laser. An IR camera would be nice for LVO, not as effective as they were in the past as airports have ben upgrading their lights to LED based with done give off the same heat.

moyangmm wrote:

But then why SQ need to spend the extra money on their 7 ULR if they could just order normal A350?

When SQ ordered the A350-900ULR it was better than a normal A350. The ULR had multiple small improvements including aerodynamics, higher MTOW, weight reduction and fuel system. These upgrades cost extra money.

5 years later all of these improvements come standard in a normal A350. In fact the normal A350 has now gone above the 280t MTOW of the ULR and it is now at 283t.

The first A350-900 had a MTOW of only 268t. These would have struggled to do SIN-LAX with a typical passenger load unless the weather conditions were perfect. A few years later the MTOW went up to 275t and these are the ones that first flew the SIN-LAX route. The 280t and 283t can do the SIN-LAX extremely easy even with either higher density cabins or with additional cargo in the hold.

Singapore to New York is longer but the A350-900ULR did it very easily with the 161 seats. It could definitely have more seats. The normal higher 283t MTOW could easily do the route with 200+ seats.

Blocking seats is standard practice on ultra long haul. When the weather is bad airlines will block a few rows of economy seats. Airlines will then fit out their cabins with slightly more seats providing it can fly the route the vast majority of the time.

I have seen a ultra long haul route get cancelled because the airline underestimated the number of days where they had to block seats due to bad weather.

Singapore to New York could definitely be flown by a normal 283t A350-900 fitted with 250 seats. I estimate it could fly with all seats full at least 80% of the time. The worst 20% of weather some seats would be blocked. I doubt more than 50 seats would ever need to be blocked. These blocked flights would nearly always be from New York to Sinapore direction. 50 seats is around 5,000kg. That's over 400nm worth of additional fuel that can be carried.

Airlines are fairly smart. For instance they could always sell 250 seats eastbound. But westbound they could sell 200 seats. But on the day if the weather is good they can list some extra seats for sale.

zeke wrote:

keesje wrote:

I guess the visual aspect is interesting, having aircraft look at its surroundings, processing the information and acting upon it. Next to the more regular available situational awareness (GPS, height, speed, ATC, weight, wind, tempearature, airport maps, etc.) . Automotive have been doing groundwork here.

Isabelle Lacaze, head of the DragonFly demonstrator at Airbus UpNext said, “These tests are one of several steps in the methodical research of technologies to further enhance operations and improve safety. “Inspired by biomimicry, the systems being tested have been designed to identify features in the landscape that enable an aircraft to ‘see’ and safely maneuver autonomously within its surroundings, in the same way that dragonflies are known to have the ability to recognize landmarks.”

source: https://www.aerospacetestinginternation ... -a350.html

Wonder if one camera is IR, and the other time of flight laser. An IR camera would be nice for LVO, not as effective as they were in the past as airports have ben upgrading their lights to LED based with done give off the same heat.

I guess the system research behind this is the use of augmented reality, interpretation, usebility of visual data in a highly regulated and demanding environment. During critical situations.

MrHMSH wrote:

moyangmm wrote:

flipdewaf wrote:

Are 253 paying passengers not meaningful payload?

They are. But the point is when non-ULR planes were used to fly SIN-NYC, they were filled no where near full 253 capacity, were they?

I'm surprised you haven't claimed the A359 needs fuel stops in SGN, NRT, ANC and YYZ to make this route.

most everybody knows the A359 can fly SIN to lax or SFO but ORD or NYC? That's a "whole 'Nuther Story"..

strfyr51 wrote:

most everybody knows the A359 can fly SIN to lax or SFO but ORD or NYC? That's a "whole 'Nuther Story"..

It is a very simple story.

Singapore to Los Angeles is 7,609 nm
Singapore to New York is 8,284 nm

New York is only 675nm further.

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

The normal A350-900 now has a 283t MTOW. That is 8t higher. That means 8t of extra fuel can be carried.

An Airbus A350 XWB is powered by 2 × Rolls Royce Trent XWB engines which consume around 5,000–5,800 kgs per hour, while cruising at an altitude of 38,000 feet (11,582 m) at a typical cruising speed of 945–1,000 km/h.

https://www.quora.com/How-much-fuel-is- ... -in-1-hour

8t of extra fuel then allows for between 1 hour 20 minutes to 1 hour 35 minutes of extra flying time.

The A350 cruises at 488 knots meaning it flies 488nm in one hour. So that extra 8t of extra fuel allows for between 650nm and 750nm additional range.

As New York is only 675nm further the normal 283t A350 will be able to do the route. End of story.

moyangmm wrote:

But then why SQ need to spend the extra money on their 7 ULR if they could just order normal A350?

Airbus have an iterative and incremental development process. In other words, the capabilities and performance of he A350 is constantly improving. An A350 delivered in 2015 is very different from an A350 delivered in 2023. When discussing the A350, it will always be in it's newest variety.

SQ got the first 7 frames where MTOW were increased to 280 t, where the new winglets was installed, and also a wing twist etc. These were branded "ULR" for marketing purposes. The A350s that will be delivered this year, have lower OEW (New Production Standard), increased MTOW to 283 t, newer engines PIP and lots of other improvements. Newly delivered frames are more ULH capable than SQs "ULRs".

moyangmm wrote:

Also, SQ is leaving potential revenue on the table by only install 161 seats, instead of 253. Something doesn't add up, no?

This is a business decision. Remember that everyting in relation to first and business class, including seats etc. weigh much more and takes up more cabin space. You make it sound like the cabin is partly empty. Putting in Y-seats would reduce the number of premium seats.

There is a premium cost of flying ULH non-stop, and SQ wants to attract the highest paying pax. That's pax that are willing to pay more to fly non-stop. The lowest class is therefore premium economy.

Completion for regular Y-class passengers is high, and Y-class passengers might prefer a one-stop flight if that means saving a few dollars and stretching their legs at the same time.

reidar76 wrote:

SQ got the first 7 frames where MTOW were increased to 280 t, where the new winglets was installed, and also a wing twist etc. These were branded "ULR" for marketing purposes. The A350s that will be delivered this year, have lower OEW (New Production Standard), increased MTOW to 283 t, newer engines PIP and lots of other improvements. Newly delivered frames are more ULH capable than SQs "ULRs".

The ULR also has ~18% higher fuel capacity than the standard A350. Even with all the improvements to the normal A350 the ULR can stand fly further, as Airbus has not improved the fuel efficiency of the base A350 by 18%. The distance where the ULR can fly more passengers has shifted to the right some since it’s launch though. Technically there is really nothing stopping Airbus from applying all those improvements to the ULR other than the lack of need and orders.

Polot wrote:

The ULR also has ~18% higher fuel capacity than the standard A350. Even with all the improvements to the normal A350 the ULR can stand fly further, as Airbus has not improved the fuel efficiency of the base A350 by 18%.

I'm so certain that I have read somewhere that the 166 488 litres fuel capacity was now avaliable with all new A350s, but now I can't find a source for that. I would say it came with the NPS and 283 t MTOW, but as long as I can't find a source, I stand corrected.

Airbus do list 283 t and the 166 488 litres fuel capacity on the specification page, under the heading "A350-900":
https://aircraft.airbus.com/en/aircraft ... t/a350-900

reidar76 wrote:

Polot wrote:

The ULR also has ~18% higher fuel capacity than the standard A350. Even with all the improvements to the normal A350 the ULR can stand fly further, as Airbus has not improved the fuel efficiency of the base A350 by 18%.

I'm so certain that I have read somewhere that the 166 488 litres fuel capacity was now avaliable with all new A350s, but now I can't find a source for that. I would say it came with the NPS and 283 t MTOW, but as long as I can't find a source, I stand corrected.

Airbus do list 283 t and the 166 488 litres fuel capacity on the specification page, under the heading "A350-900":
https://aircraft.airbus.com/en/aircraft ... t/a350-900

I’m sure if there is a new ULR order Airbus would raise the MTOW to current standard if desired. But the ULR denotes the extra fuel capacity, and there are some structural and CoG limitations around it.

reidar76 wrote:

Airbus do list 283 t and the 166 488 litres fuel capacity on the specification page, under the heading "A350-900":
https://aircraft.airbus.com/en/aircraft ... t/a350-900

On the improved version with 283 t MTOW and 166 488 L fuel capacity, is the front cargo deactivated like ULR?

moyangmm wrote:

reidar76 wrote:

Airbus do list 283 t and the 166 488 litres fuel capacity on the specification page, under the heading "A350-900":
https://aircraft.airbus.com/en/aircraft ... t/a350-900

On the improved version with 283 t MTOW and 166 488 L fuel capacity, is the front cargo deactivated like ULR?

No

RJMAZ wrote:

strfyr51 wrote:

most everybody knows the A359 can fly SIN to lax or SFO but ORD or NYC? That's a "whole 'Nuther Story"..

It is a very simple story.

Singapore to Los Angeles is 7,609 nm
Singapore to New York is 8,284 nm

New York is only 675nm further.

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

The normal A350-900 now has a 283t MTOW. That is 8t higher. That means 8t of extra fuel can be carried.

An Airbus A350 XWB is powered by 2 × Rolls Royce Trent XWB engines which consume around 5,000–5,800 kgs per hour, while cruising at an altitude of 38,000 feet (11,582 m) at a typical cruising speed of 945–1,000 km/h.

https://www.quora.com/How-much-fuel-is- ... -in-1-hour

8t of extra fuel then allows for between 1 hour 20 minutes to 1 hour 35 minutes of extra flying time.

The A350 cruises at 488 knots meaning it flies 488nm in one hour. So that extra 8t of extra fuel allows for between 650nm and 750nm additional range.

As New York is only 675nm further the normal 283t A350 will be able to do the route. End of story.

Being able to carry 8T more fuel does not mean that is all extra range. As you are flying for 16+ hours with 8T extra weight - that means extra fuel consumption for those first 16 hours. I don't know if there is a rule of thumb but I seem to recall that far out on the performance envelope means something like about half of that extra fuel gives you more range - so more like 350-400NM added range for 8T higher MTOW.

That being said I think the A350 when empty of fuel is burning less than 5T per hour. Something one of the A350 gurus can confirm.

morrisond wrote:

RJMAZ wrote:

strfyr51 wrote:

most everybody knows the A359 can fly SIN to lax or SFO but ORD or NYC? That's a "whole 'Nuther Story"..

It is a very simple story.

Singapore to Los Angeles is 7,609 nm
Singapore to New York is 8,284 nm

New York is only 675nm further.

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

The normal A350-900 now has a 283t MTOW. That is 8t higher. That means 8t of extra fuel can be carried.

An Airbus A350 XWB is powered by 2 × Rolls Royce Trent XWB engines which consume around 5,000–5,800 kgs per hour, while cruising at an altitude of 38,000 feet (11,582 m) at a typical cruising speed of 945–1,000 km/h.

https://www.quora.com/How-much-fuel-is- ... -in-1-hour

8t of extra fuel then allows for between 1 hour 20 minutes to 1 hour 35 minutes of extra flying time.

The A350 cruises at 488 knots meaning it flies 488nm in one hour. So that extra 8t of extra fuel allows for between 650nm and 750nm additional range.

As New York is only 675nm further the normal 283t A350 will be able to do the route. End of story.

Being able to carry 8T more fuel does not mean that is all extra range. As you are flying for 16+ hours with 8T extra weight - that means extra fuel consumption for those first 16 hours. I don't know if there is a rule of thumb but I seem to recall that far out on the performance envelope means something like about half of that extra fuel gives you more range - so more like 350-400NM added range for 8T higher MTOW.

That being said I think the A350 when empty of fuel is burning less than 5T per hour. Something one of the A350 gurus can confirm.

Fairly simple to calculate the effect really, the fuel burn from 275t to 280 t is at about 7.5t/hr so will get you just about 1hr and 5 mins or about 500nm extra.

Fred

RJMAZ wrote:

strfyr51 wrote:

most everybody knows the A359 can fly SIN to lax or SFO but ORD or NYC? That's a "whole 'Nuther Story"..

It is a very simple story.

Singapore to Los Angeles is 7,609 nm
Singapore to New York is 8,284 nm

New York is only 675nm further.

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

The normal A350-900 now has a 283t MTOW. That is 8t higher. That means 8t of extra fuel can be carried.

https://www.quora.com/How-much-fuel-is- ... -in-1-hour

8t of extra fuel then allows for between 1 hour 20 minutes to 1 hour 35 minutes of extra flying time.

The A350 cruises at 488 knots meaning it flies 488nm in one hour. So that extra 8t of extra fuel allows for between 650nm and 750nm additional range.

As New York is only 675nm further the normal 283t A350 will be able to do the route. End of story.

It's not that simple for the simple fact that SIN-NYC is almost never flown by the GC route and without weather. Weather and alternates can change the route significantly. Yesterday's SIN-JFK for example was 9,033nm and nearly 18 hours.
https://flightaware.com/live/flight/SIA ... /WSSS/KJFK
On the same day, SIN-LAX was 7859nm and just a hair over 15 hours. That's close to a 1,200nm difference and an extra 3 hours of flight time.
https://flightaware.com/live/flight/SIA ... /WSSS/KLAX
Bottom line is you can't fly a standard A359 for 18 hours with ~250 pax. You can make it close (see PAL JFK-MNL), but not all the way.

airbazar wrote:

RJMAZ wrote:

strfyr51 wrote:

most everybody knows the A359 can fly SIN to lax or SFO but ORD or NYC? That's a "whole 'Nuther Story"..

It is a very simple story.

Singapore to Los Angeles is 7,609 nm
Singapore to New York is 8,284 nm

New York is only 675nm further.

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

The normal A350-900 now has a 283t MTOW. That is 8t higher. That means 8t of extra fuel can be carried.

https://www.quora.com/How-much-fuel-is- ... -in-1-hour

8t of extra fuel then allows for between 1 hour 20 minutes to 1 hour 35 minutes of extra flying time.

The A350 cruises at 488 knots meaning it flies 488nm in one hour. So that extra 8t of extra fuel allows for between 650nm and 750nm additional range.

As New York is only 675nm further the normal 283t A350 will be able to do the route. End of story.

It's not that simple for the simple fact that SIN-NYC is almost never flown by the GC route and without weather. Weather and alternates can change the route significantly. Yesterday's SIN-JFK for example was 9,033nm and nearly 18 hours.
https://flightaware.com/live/flight/SIA ... /WSSS/KJFK
On the same day, SIN-LAX was 7859nm and just a hair over 15 hours. That's close to a 1,200nm difference and an extra 3 hours of flight time.
https://flightaware.com/live/flight/SIA ... /WSSS/KLAX
Bottom line is you can't fly a standard A359 for 18 hours with ~250 pax. You can make it close (see PAL JFK-MNL), but not all the way.

According to FR24 it has taken around 17:20 basically every day for the last week and today is due to take 17:02. Are you sure you’re seeing flight time and not gate to gate?

No routes are flown great circle however the longer the flight the less affected by winds it will tend to be as a percentage of distance on average (more route options available).

As calculated previously a 253seat A359 is capable of at least 8660nm SAR. That’s about 18hrs 8mins aloft in the real world.

Fred


Sent from my iPad using Tapatalk

flipdewaf wrote:

airbazar wrote:

RJMAZ wrote:

It is a very simple story.

Singapore to Los Angeles is 7,609 nm
Singapore to New York is 8,284 nm

New York is only 675nm further.

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

The normal A350-900 now has a 283t MTOW. That is 8t higher. That means 8t of extra fuel can be carried.

https://www.quora.com/How-much-fuel-is- ... -in-1-hour

8t of extra fuel then allows for between 1 hour 20 minutes to 1 hour 35 minutes of extra flying time.

The A350 cruises at 488 knots meaning it flies 488nm in one hour. So that extra 8t of extra fuel allows for between 650nm and 750nm additional range.

As New York is only 675nm further the normal 283t A350 will be able to do the route. End of story.

It's not that simple for the simple fact that SIN-NYC is almost never flown by the GC route and without weather. Weather and alternates can change the route significantly. Yesterday's SIN-JFK for example was 9,033nm and nearly 18 hours.
https://flightaware.com/live/flight/SIA ... /WSSS/KJFK
On the same day, SIN-LAX was 7859nm and just a hair over 15 hours. That's close to a 1,200nm difference and an extra 3 hours of flight time.
https://flightaware.com/live/flight/SIA ... /WSSS/KLAX
Bottom line is you can't fly a standard A359 for 18 hours with ~250 pax. You can make it close (see PAL JFK-MNL), but not all the way.

According to FR24 it has taken around 17:20 basically every day for the last week and today is due to take 17:02. Are you sure you’re seeing flight time and not gate to gate?

No routes are flown great circle however the longer the flight the less affected by winds it will tend to be as a percentage of distance on average (more route options available).

As calculated previously a 253seat A359 is capable of at least 8660nm SAR. That’s about 18hrs 8mins aloft in the real world.

Fred


Sent from my iPad using Tapatalk

Don't you need at least 45min for reserves and then possibly more for ETOPS? Or is that included?

morrisond wrote:

flipdewaf wrote:

airbazar wrote:

It's not that simple for the simple fact that SIN-NYC is almost never flown by the GC route and without weather. Weather and alternates can change the route significantly. Yesterday's SIN-JFK for example was 9,033nm and nearly 18 hours.
https://flightaware.com/live/flight/SIA ... /WSSS/KJFK
On the same day, SIN-LAX was 7859nm and just a hair over 15 hours. That's close to a 1,200nm difference and an extra 3 hours of flight time.
https://flightaware.com/live/flight/SIA ... /WSSS/KLAX
Bottom line is you can't fly a standard A359 for 18 hours with ~250 pax. You can make it close (see PAL JFK-MNL), but not all the way.

According to FR24 it has taken around 17:20 basically every day for the last week and today is due to take 17:02. Are you sure you’re seeing flight time and not gate to gate?

No routes are flown great circle however the longer the flight the less affected by winds it will tend to be as a percentage of distance on average (more route options available).

As calculated previously a 253seat A359 is capable of at least 8660nm SAR. That’s about 18hrs 8mins aloft in the real world.

Fred


Sent from my iPad using Tapatalk

Don't you need at least 45min for reserves and then possibly more for ETOPS? Or is that included?

Included 5t of reserves, that’s worth about 70+mins.

Fred


Sent from my iPad using Tapatalk

flipdewaf wrote:

morrisond wrote:

flipdewaf wrote:

According to FR24 it has taken around 17:20 basically every day for the last week and today is due to take 17:02. Are you sure you’re seeing flight time and not gate to gate?

No routes are flown great circle however the longer the flight the less affected by winds it will tend to be as a percentage of distance on average (more route options available).

As calculated previously a 253seat A359 is capable of at least 8660nm SAR. That’s about 18hrs 8mins aloft in the real world.

Fred


Sent from my iPad using Tapatalk

Don't you need at least 45min for reserves and then possibly more for ETOPS? Or is that included?

Included 5t of reserves, that’s worth about 70+mins.

Fred


Sent from my iPad using Tapatalk

I cannot imagine any pilot or dispatcher ever accepting 5 tonnes of reserves on any A350 model. Thats only about 11,000 lbs. In my (real world) experience, most pilots want about double that. You've got not only reserves to calculate but alternate burn also, and the aforementioned ETOPS reserve (to cover the ETOPS critical fuel scenario).

And keep in mind "cost to carry." Cost to carry an additional 11,000 lbs of fuel on a 16 hour flight might be 50%, another 5,500 lbs. So now, you have to come up with 16,500 lbs somewhere.

JohanTally wrote:

moyangmm wrote:

reidar76 wrote:

Airbus do list 283 t and the 166 488 litres fuel capacity on the specification page, under the heading "A350-900":
https://aircraft.airbus.com/en/aircraft ... t/a350-900

On the improved version with 283 t MTOW and 166 488 L fuel capacity, is the front cargo deactivated like ULR?

No

Interesting. Why ULR need to deactivate the front cargo then? Can SQ reactivate the front cargo cabin on their 7 ULR? It would be profitable for SQ to add some cargo volume...

SteelChair wrote:

flipdewaf wrote:

morrisond wrote:

Don't you need at least 45min for reserves and then possibly more for ETOPS? Or is that included?

Included 5t of reserves, that’s worth about 70+mins.

Fred


Sent from my iPad using Tapatalk

I cannot imagine any pilot or dispatcher ever accepting 5 tonnes of reserves on any A350 model. Thats only about 11,000 lbs. In my (real world) experience, most pilots want about double that. You've got not only reserves to calculate but alternate burn also, and the aforementioned ETOPS reserve (to cover the ETOPS critical fuel scenario).

Seems acceptable for UA on a 787-10 - 4990kg viewtopic.php?t=1406387&start=400

Also acceptable for QF on 787-9 - 4.5t viewtopic.php?f=5&t=1406387&start=100 reply 112.

Lots of others do feel comfortable.

SteelChair wrote:

And keep in mind "cost to carry." Cost to carry an additional 11,000 lbs of fuel on a 16 hour flight might be 50%, another 5,500 lbs. So now, you have to come up with 16,500 lbs somewhere.

That’s exactly why you wouldn’t carry that much when it’s evidently not needed.

Fred


Sent from my iPad using Tapatalk

moyangmm wrote:

JohanTally wrote:

moyangmm wrote:

On the improved version with 283 t MTOW and 166 488 L fuel capacity, is the front cargo deactivated like ULR?

No

Interesting. Why ULR need to deactivate the front cargo then? Can SQ reactivate the front cargo cabin on their 7 ULR? It would be profitable for SQ to add some cargo volume...

I believe it is possible for the ULR to be converted after installing the cargo management system in the forward hold. I'm not sure what else has to be done but I'd expect it to be mostly paperwork.

RJMAZ wrote:

A few years later the MTOW went up to 275t and these are the ones that first flew the SIN-LAX route.

RJMAZ wrote:

Singapore to Los Angeles has been successfully operated by normal 275t MTOW A350. As you say everybody knows this.

That's actually incorrect. The 275t aircraft never operated scheduled service into LAX, and to my knowledge have substituted only thrice (no idea what the loads were).

Perhaps you're confusing it with SFO, who did begin scheduled service with the 275t aircraft?
LAX did not. Scheduled service did not come until November 2018 with 9V-SGC, a -ULR.

The -ULRs operated the nonstop exclusively until Covid.
The first to resume LAX-SIN after Covid was 9V-SMV, a 280t bird.

moyangmm wrote:

Interesting. Why ULR need to deactivate the front cargo then?

Because the additional fuel is added to the extant center fuel tank, which significantly shifts the aircraft's center of gravity forward.

Requiring the forward cargo bay to be empty, helps balance this out.

moyangmm wrote:

Can SQ reactivate the front cargo cabin on their 7 ULR? It would be profitable for SQ to add some cargo volume...

Yes, but not white it's operating under the specifications of the -ULR variant.

A350-941 built in 2019 has a certified fuel capacity of 110400kg. Using Airbus FlySmart, a 8500nm sector at M.85. 0 HW component, ISA, TOW 280t will require 103.3t of fuel and will take 17h47min.

T54A wrote:

A350-941 built in 2019 has a certified fuel capacity of 110400kg. Using Airbus FlySmart, a 8500nm sector at M.85. 0 HW component, ISA, TOW 280t will require 103.3t of fuel and will take 17h47min.

What proportion of the 110400kg is 103.3t?

T54A wrote:

A350-941 built in 2019 has a certified fuel capacity of 110400kg. Using Airbus FlySmart, a 8500nm sector at M.85. 0 HW component, ISA, TOW 280t will require 103.3t of fuel and will take 17h47min.

Indeed, the fuel capacity of the non ULR was the limiting factor for SQ. They took 111.5t of fuel on the first SQ22 with the A350.

Fred

JerseyFlyer wrote:

T54A wrote:

A350-941 built in 2019 has a certified fuel capacity of 110400kg. Using Airbus FlySmart, a 8500nm sector at M.85. 0 HW component, ISA, TOW 280t will require 103.3t of fuel and will take 17h47min.

What proportion of the 110400kg is 103.3t?

Metric maths is pretty straightforward - 110,400kg = 110.4t

LAX772LR wrote:

Because the additional fuel is added to the extant center fuel tank, which significantly shifts the aircraft's center of gravity forward.

Requiring the forward cargo bay to be empty, helps balance this out.

Absolute hogwash, the index for 115 of fuel tonnes is only -454, the index maximum load in the or forward hold is -1622, the index for the maximum for the aft cargo hold is +948

The ULR tanks are the same 3 tanks as the normal -900, just different liquid levels.