It has been reported that UA plans to upgrade the software in a sub-fleet and eventually all 789s. This software upgrade will increase thrust and improve the fuel management systems, thus increasing the range and capabilities of the aircraft. The software update is what will allow SFO-BLR and EWR-JNB possible.

https://onemileatatime.com/united-airli ... BPguQEjWjg

What are your thoughts of such an upgrade? Was this and upgrade in conjunction with Boeing, a third party company, or on their own? Will the update then be extended to the 788 and 78X to improve their range and capabilities? Finally, will other airlines follow suit?

Please do not remove, this post is not fully about UA and should not be consolidated.

Thrust bump couldn’t happen without engine/airframe mfr. support.

As noted, these are software changes so they would have to be done in conjunction with the OEMs.

Did UA take the highest thrust option on their GEnx engines? If not, then this could just be them doing so. It's also possible the fuel management software upgrades are part of the thrust bump package.

The change is only happening to a specific number of frames that will be dedicated to servicing those routes at first, but reports state it will eventually be rolled out across the 787-9 fleet at United.

I have to wonder if QF could consider incorporating this as well, as, albeit in a less dense configuration, prior to COVID-19, they were flying PER-LHR, which is even longer than SFO-BLR. It could also be useful to EY and could swing a potential order for EK with GE engines.

Is it being implied that the B789 is getting a new expansion of range, or just that UAL is upgrading to a higher thrust version?

LCDFlight wrote:

Is it being implied that the B789 is getting a new expansion of range, or just that UAL is upgrading to a higher thrust version?

A quick Google search did not come up with any hits about a recent maximum thrust increase for the GEnx or fuel management updates for the 787 family, I am inclined to think this is UA purchasing a higher-thrust setting and the fuel management changes are part of that package (guessing it's all tied into software updates to the FAEDEC).

The A350 could use one to finally be considered a long haul aircraft on A.net
But in all seriousness this looks like just a thrust bump, which will help with a lot of flights, in Australia when it’s 35-40+ degrees, JNB of course at 5500AM, and BLR can get hot and it’s 3000ft AMSL, overall a win win.

Airlines0613 wrote:

It has been reported that UA plans to upgrade the software in a sub-fleet and eventually all 789s. This software upgrade will increase thrust and improve the fuel management systems, thus increasing the range and capabilities of the aircraft. The software update is what will allow SFO-BLR and EWR-JNB possible.

https://onemileatatime.com/united-airli ... BPguQEjWjg

What are your thoughts of such an upgrade? Was this and upgrade in conjunction with Boeing, a third party company, or on their own? Will the update then be extended to the 788 and 78X to improve their range and capabilities? Finally, will other airlines follow suit?

Please do not remove, this post is not fully about UA and should not be consolidated.

When i look at that link you included it has nothing in it regarding a thrust bump or a range increase.

zeke wrote:

When i look at that link...it has nothing in it regarding a thrust bump or a range increase.

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

I understand higher thrust - but software changes to the fuel management system. What could it be?

Perhaps fuel tank capacity change a’la A350ULR, without any physical change to the tanks?

thepinkmachine wrote:

I understand higher thrust - but software changes to the fuel management system. What could it be?

Perhaps fuel tank capacity change a’la A350ULR, without any physical change to the tanks?

The reason I think it may be related to the thrust increase is that the change is only being made on the handful of UA 787-9 getting the thrust increase now and then will be rolled out to the entire fleet (so they will all be certified for a higher thrust and receive the fuel management system update).

If the FMS update was independent of the thrust increase, one would think it would be rolling out to other carriers (even if UA was the first to receive it). And I would think we would have heard about it via the aviation media or a Boeing press release.

I know there have been plenty of threads talking about the 789's hot and high performance, but it did surprise me to hear that UA is launching EWR-JNB on the 789. However, it's fantastic to see the airplane have such capabilities.

Are there any other improvements that are being talked about to optimize performance on the 789 to operate out of hot and high airports? I understand that the tire speed on the 777 can be an issue, is this expected to impact the 789 at JNB too?

Good to hear and hope they can make even more improvements. The 789 is going to be the optimal size aircraft for the coming years for most carrier's long haul needs. A midsize aircraft that can really take you almost anywhere.

Stitch wrote:

The reason I think it may be related to the thrust increase is that the change is only being made on the handful of UA 787-9 getting the thrust increase now and then will be rolled out to the entire fleet (so they will all be certified for a higher thrust and receive the fuel management system update).

I personally think this is just a thrust bump like found on other aircraft, not really an increase in the rated thrust at all, just the ability to maintain full rated thrust to a higher density altitude.

Eg on the Trent 700

“The Trent 772C-60 has the same ratings as the 772B-60 except at altitudes above 2440 m (8,000 ft) where the 772C can provide more thrust in both Take-Off and Continuous conditions. The extent of this thrust increase is dependent upon altitude, temperature and Mach number, but is limited to a maximum of 8.5%. From 3048 m (10,000 ft) to 4877 m (16,000 ft) there is a Take-Off thrust increase of 3% for day temperatures of ISA +28oC and above, this reduces to 0% at ISA +18oC and below. At altitudes greater than 3962 m (13,000 ft) and Mach numbers greater than 0.4 a further thrust increase results from maximum continuous thrust exceeding maximum Take-Off thrust, this increases the maximum Take-Off thrust below ISA +15oC by a maximum of 5.0% relative to the Trent 772B-60 at 4877 m (16,000 ft), 0.5 Mn. Max Continuous thrust is increased by up to 8.5% relative to the Trent 772B-60 rating for altitudes between 4572 m (15,000 ft) and 7620 m (25,000 ft) for Mach numbers between 0.3 and 0.6 and temperatures from ISA to ISA +30oC.“

The fadec software changes (people often call this a pin plug) is not free, it costs the airline to obtain this thrust bump as performance data has to be paid for, it also results in higher maintenance costs and lower on wing time for the engine. Therefore results in higher operating costs for the aircraft.

I don’t think there is any range increase due to decreased fuel burn, more likely the RTOW data permits more fuel to be uplifted under given conditions. Generally speaking if these thrust bumps are used regularly the engine will degrade quicker resulting in higher fuel burns.

Stitch wrote:

zeke wrote:

When i look at that link...it has nothing in it regarding a thrust bump or a range increase.

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

In the article it says

Specifically, it has increased engine thrust and altered the fuel management system to squeeze more range out of the fleet. (Both of these are software changes.

which indicates 787-9 now practically has an ULR variant. This is an exciting news. UA can now use this ultra long-haul 787-9 to compete on routes like EWR-SIN. Since they use 787 they have advantages on fuel efficiency over their competitors.

moyangmm wrote:

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

In the article it says

Specifically, it has increased engine thrust and altered the fuel management system to squeeze more range out of the fleet. (Both of these are software changes.

I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

zeke wrote:

moyangmm wrote:

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

In the article it says

Specifically, it has increased engine thrust and altered the fuel management system to squeeze more range out of the fleet. (Both of these are software changes.

I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

What I suspect UA is doing is upgrading the GEnx to the 787-10 spec, which has already been certified on the 787-9 as a high thrust option concurrently with the 787-10 certification in 2018 (see page 9-10 at https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/39719ee9447ccc67862585e300696651/$FILE/T00021SE_Rev34.pdf). It simply means writing a check to GE for the higher-thrust FADEC plug.

United857 wrote:

zeke wrote:

moyangmm wrote:

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

In the article it says

Specifically, it has increased engine thrust and altered the fuel management system to squeeze more range out of the fleet. (Both of these are software changes.

I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

What I suspect UA is doing is upgrading the GEnx to the 787-10 spec, which has already been certified on the 787-9 as a high thrust option concurrently with the 787-10 certification in 2018 (see page 9-10 at https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/39719ee9447ccc67862585e300696651/$FILE/T00021SE_Rev34.pdf). It simply means writing a check to GE for the higher-thrust FADEC plug.

As Zeke correctly wrote, you can't just increase thrust. Controllability and rudder size play a role. The 787-10 can have more powerful engines because it is longer, so the rudder acts on a longer arm.
I for one think Zeke is right about this being a thrust bump for certain conditions, allowing them to uplift more.

moyangmm wrote:

Since they use 787 they have advantages on fuel efficiency over their competitors.

Not really tho. If you really are right about this upgrade, don't forget that you get more power by essentially burning more fuel. That will probably put it at a disadvantage compared to an A350-900 and certainly against a normal 787-9. You also wear out the components faster. Nothing is free.

VSMUT wrote:

As Zeke correctly wrote, you can't just increase thrust. Controllability and rudder size play a role. The 787-10 can have more powerful engines because it is longer, so the rudder acts on a longer arm.
I for one think Zeke is right about this being a thrust bump for certain conditions, allowing them to uplift more.

I think the poster was talking about the 78 klb rated GEnx, as it’s already certified on the 789. However as I understand it the UA 787-10 are fitted with 67 klb engines.

The best engines for hot and high on the 789 currently is the RR, they are 78 klb but flat rated to 33 deg C, where the GEnx is flat rated to 30 deg C, the RR also has a higher MCT.

VSMUT wrote:

As Zeke correctly wrote, you can't just increase thrust. Controllability and rudder size play a role. The 787-10 can have more powerful engines because it is longer, so the rudder acts on a longer arm.
I for one think Zeke is right about this being a thrust bump for certain conditions, allowing them to uplift more.

One thing worth mentioning here is Thrust Asymmetry Protection - a 787 feature, which automatically reduces thrust on the live engine, when speed drops below V2, in order to maintain better controllability at low weights. Boeing says it doesn't adversely affect the performance, as reduced asymmetry drag offsets lower thrust.

I'm not sure to what extent it lowers certified Vmc speeds, but if it could be taken into account, then it could enable installing more powerful engines without eg. increasing the vertical stabilizer area

thepinkmachine wrote:

One thing worth mentioning here is Thrust Asymmetry Protection - a 787 feature, which automatically reduces thrust on the live engine, when speed drops below V2, in order to maintain better controllability at low weights. Boeing says it doesn't adversely affect the performance, as reduced asymmetry drag offsets lower thrust.

I'm not sure to what extent it lowers certified Vmc speeds, but if it could be taken into account, then it could enable installing more powerful engines without eg. increasing the vertical stabilizer area

At low weights is the key word. A 787-9 flying long distances won't be at low weights. The last thing you want at MTOM after an engine failure is for the remaining engine to deliver less power. IMO, it's a safety feature, not a performance booster.

VSMUT wrote:

At low weights is the key word. A 787-9 flying long distances won't be at low weights. The last thing you want at MTOM after an engine failure is for the remaining engine to deliver less power. IMO, it's a safety feature, not a performance booster.

Well, at high weights Vmc is generally not an issue.

moyangmm wrote:

Since they use 787 they have advantages on fuel efficiency over their competitors.

you might want to have a look at the A350 Boeing 787 fuel burn thread in tech ops. ..... if you can find it, because i just couldn´t....

best regards
Thomas

2 interesting routes there JNB is all about the thrust bump, Range in and of itself would never have really been an issue out of JNB, just that its high up and more thrust means you can get up at a heavier weight.

The BLR route does throw up some interesting questions as it is indeed ~250nm further than the SFO sin route that struggled. My take here though is that whilst the two routes might superficially look similar the likely hood of encountering the winds that made the SFO-SIN route so difficult may well be very different.
http://www.gcmap.com/mapui?P=SFO-BLR%2C ... =wls&DU=nm
The Routes shown on GCMAP show the initial headings being somewhat different and my cursory glance on Windy.com shows that there may be good potential to avoid the winds with the more polar route possible. 250nm miles more great circle range, may be somewhat less SAR.

We know what the 789 is capable of from the QF9 flights (8202nm SAR I believe) so the SFO-BLR flight shouldn't be too much of a stretch with another 20odd pax if the winds are ok.

Final slightly off topic point, knowing the 789 capabilities and the GC distance of the SFO-SIN flight, those winds must have been ferocious!

Fred

flipdewaf wrote:

The BLR route does throw up some interesting questions as it is indeed ~250nm further than the SFO sin route that struggled. My take here though is that whilst the two routes might superficially look similar the likely hood of encountering the winds that made the SFO-SIN route so difficult may well be very different.

I ran plans SFO-BLR and BLR-SFO, SFO-BLR carried around 34 tonnes, flight time 16:55, and the reverse same payload 16:40.

zeke wrote:

flipdewaf wrote:

The BLR route does throw up some interesting questions as it is indeed ~250nm further than the SFO sin route that struggled. My take here though is that whilst the two routes might superficially look similar the likely hood of encountering the winds that made the SFO-SIN route so difficult may well be very different.

I ran plans SFO-BLR and BLR-SFO, SFO-BLR carried around 34 tonnes, flight time 16:55, and the reverse same payload 16:40.

16:40 and 16:55 suggests about 3kts effective head/tailwind, so low.

Is that for the 789? the loads look high.

Fred

flipdewaf wrote:

zeke wrote:

16:40 and 16:55 suggests about 3kts effective head/tailwind, so low.

Is that for the 789? the loads look high.

Fred

Yes 789, the 34 tonnes would include catering, no cargo either direction if full passenger load carried.

The eastbound track had a good tailwind across the pacific, the westbound route over Alaska, Russia, China, not quite polar. It is however summer, winds are light.

If the thrust bump just helps "hot and high" ops, I wonder why UA is planning to add it to the entire 787-9 fleet (as the articles state) and not just the frames that will be dedicated to serving these two routes. Yes, it offers a bigger pool of frames for substitution reasons, but seems an unnecessary expense for an option that sounds like it would be unnecessary for most ops.

VSMUT wrote:

United857 wrote:

zeke wrote:

In the article it says



I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

What I suspect UA is doing is upgrading the GEnx to the 787-10 spec, which has already been certified on the 787-9 as a high thrust option concurrently with the 787-10 certification in 2018 (see page 9-10 at https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/39719ee9447ccc67862585e300696651/$FILE/T00021SE_Rev34.pdf). It simply means writing a check to GE for the higher-thrust FADEC plug.

As Zeke correctly wrote, you can't just increase thrust. Controllability and rudder size play a role. The 787-10 can have more powerful engines because it is longer, so the rudder acts on a longer arm.
I for one think Zeke is right about this being a thrust bump for certain conditions, allowing them to uplift more.

moyangmm wrote:

Since they use 787 they have advantages on fuel efficiency over their competitors.

Not really tho. If you really are right about this upgrade, don't forget that you get more power by essentially burning more fuel. That will probably put it at a disadvantage compared to an A350-900 and certainly against a normal 787-9. You also wear out the components faster. Nothing is free.

There are higher thrust versions on the 787-9 type certificate that are already certified, which were not available when UA originally got the planes. They were certified when those new engine ratings were developed for the 787-10, but Boeing has already done the testing work to certify it for the 787-9 as well, which is reflected in the 787-9 section of the type certificate.

When the 787-9 first came out the highest thrust options available were the 71k options. However, now there are higher thrust options available for the 787-9 up to 78k, as reflected in the 787-9 section of the type certificate.

zeke wrote:

moyangmm wrote:

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

In the article it says

Specifically, it has increased engine thrust and altered the fuel management system to squeeze more range out of the fleet. (Both of these are software changes.

I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

But ULR doesn't mean more thrust, does it? A359ULR has the same thrust as regular A359. ULR only requires more fuel and less payload.

moyangmm wrote:

zeke wrote:

moyangmm wrote:

This one does mention it: https://crankyflier.com/2020/09/10/unit ... long-haul/

In the article it says

Specifically, it has increased engine thrust and altered the fuel management system to squeeze more range out of the fleet. (Both of these are software changes.

I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

But ULR doesn't mean more thrust, does it? A359ULR has the same thrust as regular A359. ULR only requires more fuel and less payload.

‘ULR’ doesn’t actually refer to anything on a technical basis, it is a marketing moniker.

With reference to the A350 it started as a higher weight variant and the only available model with 280t was the ULR, it only later became the standard weight(as did the winglets I believe). The A350ULR also allows greater fuel volume to enable the longer routes to be operated according to the standards of the airlines.

With regard to higher thrust engines allowing greater range it is the case that when weight is limited by field length that a higher thrust would allow higher TOW and so allow greater fuel uplift and therefore greater range at a given payload. This is likely the case for the JNB-NYC route.

Fred


Sent from my iPhone using Tapatalk

flipdewaf wrote:

moyangmm wrote:

zeke wrote:

In the article it says



I don’t believe the article, aircraft cannot just increase thrust in engines, as minimum control speeds are based upon the thrust, controllability, and rudder size. Like I said in my previous post I think it’s a thrust bump which maintains the rated thrust to a higher density altitude, the maximum thrust remains the same.

Most bloggers would have no idea of control speeds etc and think that thrust is actually increasing, when it isn’t increasing, it is not degrading or degrading at a lower rate with the increase in density height.

But ULR doesn't mean more thrust, does it? A359ULR has the same thrust as regular A359. ULR only requires more fuel and less payload.

‘ULR’ doesn’t actually refer to anything on a technical basis, it is a marketing moniker.

With reference to the A350 it started as a higher weight variant and the only available model with 280t was the ULR, it only later became the standard weight(as did the winglets I believe). The A350ULR also allows greater fuel volume to enable the longer routes to be operated according to the standards of the airlines.

With regard to higher thrust engines allowing greater range it is the case that when weight is limited by field length that a higher thrust would allow higher TOW and so allow greater fuel uplift and therefore greater range at a given payload. This is likely the case for the JNB-NYC route.

Fred


Sent from my iPhone using Tapatalk

Actually, ULH does have some technical differences to enable higher fuel capacity. Extra fuel pumps, modified systems, etc to enable greater fuel volume. That extra system is not standard on regular 280T A359’s and frankly not needed.

Agree with the comments regarding thrust bumps for UA’s 789. I don’t see reason they need more max thrust at ISA, just flat rated to higher temperatures/altitudes. This prevents the extra wear and tear when not needed but allows higher weights when density altitude becomes an issue.

I could also see Boeing implementing a small change in fuel tank configuration via software to enable a small amount of extra fuel. This would be similar to the changes made on the ULH but with out the extra hardware that larger increase needed. I recall the 789 becomes fuel limited at extreme ranges.

Okcflyer wrote:

Actually, ULH does have some technical differences to enable higher fuel capacity. Extra fuel pumps, modified systems, etc to enable greater fuel volume. That extra system is not standard on regular 280T A359’s and frankly not needed.

yes, I’m aware of the changes but I was referring to there not being a specific technical hurdle or test before an aircraft can be called a ULR variant.

Fred


Sent from my iPhone using Tapatalk

Okcflyer wrote:

Actually, ULH does have some technical differences to enable higher fuel capacity. Extra fuel pumps, modified systems, etc to enable greater fuel volume. That extra system is not standard on regular 280T A359’s and frankly not needed.

Incorrect, no additional pumps, the configuration is now standard as far as I am aware. The main changes were related to fuel sensing and software.

zeke wrote:

Okcflyer wrote:

Actually, ULH does have some technical differences to enable higher fuel capacity. Extra fuel pumps, modified systems, etc to enable greater fuel volume. That extra system is not standard on regular 280T A359’s and frankly not needed.

Incorrect, no additional pumps, the configuration is now standard as far as I am aware. The main changes were related to fuel sensing and software.

Fuel pumps is a mistake. That said I understand the inerting system was upgraded along with the additional sensors?

Are you able to check and confirm?

Regards

Okcflyer wrote:

Fuel pumps is a mistake. That said I understand the inerting system was upgraded along with the additional sensors?

Per Leeham.net, who were given this information by Airbus personnel, there were modifications to the fuel control system software and sensors to allow more of the existing fuel tank volume to be used and the fuel tank inerting and venting system were also modified.

Okcflyer wrote:

That said I understand the inerting system was upgraded along with the additional sensors?

Are you able to check and confirm?

Regards

Not that I am aware, insofar that the software would need to be adjusted to account for reduced ullage. There is some misconceptions about "inerting" systems, they are really Flammability Reduction System (FRS). The air that. is used in the tank is atmospheric with O2 levels slightly reduced from around 21% to under 12%, the level where combustion is not normally supported, it is not an oxygen free, nor is a pure inert gas injected into the tank. The O2 level is reduced by a filter which could be thought of like a reverse osmosis filter used with water, the by product of the air separation filter filter is O2 which is vented to the atmosphere.

747classic wrote:

The T/O thrust will then be increased from 76700 lbs to 78500 lbs.

At sea level up to 30 deg C.

Airlines0613 wrote:

It has been reported that UA plans to upgrade the software in a sub-fleet and eventually all 789s. This software upgrade will increase thrust and improve the fuel management systems, thus increasing the range and capabilities of the aircraft. The software update is what will allow SFO-BLR and EWR-JNB possible.

https://onemileatatime.com/united-airli ... BPguQEjWjg

What are your thoughts of such an upgrade? Was this and upgrade in conjunction with Boeing, a third party company, or on their own? Will the update then be extended to the 788 and 78X to improve their range and capabilities? Finally, will other airlines follow suit?

Please do not remove, this post is not fully about UA and should not be consolidated.

since the range Boost is not just airframe related? the Airline would have to complete mods IAW per GE, Boeing and whomever builds the Flight Management system. ( I've never put a wrench on a 787 so I wouldn't Know)

Stitch wrote:

If the thrust bump just helps "hot and high" ops, I wonder why UA is planning to add it to the entire 787-9 fleet (as the articles state) and not just the frames that will be dedicated to serving these two routes. Yes, it offers a bigger pool of frames for substitution reasons, but seems an unnecessary expense for an option that sounds like it would be unnecessary for most ops.

If the expense is not onerous, it would not only help with the above, but also again should UA add more Hot & High routes at a later time. I cannot think of any on deck at the moment, but these aircraft are likely intended to be in the fleet a long enough time that this becomes a reasonable possibility/probability. I would educatedly guess that this is a less expensive proposition now than at a time further down the road.

As well, would this not also help with resale value? That is crap at the moment, no doubt, but again, there is a long time expected of these frames...

Does this actually touch anything beyond "filling out" the derating curve that reduces TOW?

i.e. by way of more available thrust the envelope is expanded to allow higher TOW. ( It doesn't touch MTOW )
.. and about how much more range ( under those limiting conditions ) are we talking about? 1..2%

Some facts for a change:

UAL B789s are all powered by GEnx-1B74/75/P2 (76,600Lbs).

Small note Zeke: /P2 is flat rated to 32.8C ( /P1 refers to flat rated to 30C),both at sea level as you already mentioned.

The highest available GEnx-1B rating on the B789 is the -1B76A/P2 (78,500Lbs). As previously mentioned above by another user, UA can cut GE and Boeing a check for the new FADEC rating plug and FCOM revision.

FYI, the highest thrust rating on the GEnx-1B is the -1B78/P2 (80,400Lbs).

Note, this rating is FAA certified since April 12, 2013. However it has yet to be certified on the 787-9 or even 787-10. In other words, while GE has long ago received FAA certification for the rating itself, Boeing has not yet received FAA certification for use the 787-9 or 787-10. This is current as of Sept. 11 2020. This does not rule out that certification of the -1B78/P2 on 787-9 or 787-10 is currently in process/pending.

I am not aware of any customer optioning their GEnx powered 787-9/10 with this rating and that would explain why Boeing has in turn not yet applied for and received FAA certification.

Qantas744er wrote:

Some facts for a change:

UAL B789s are all powered by GEnx-1B74/75/P2 (76,600Lbs).

Small note Zeke: /P2 is flat rated to 32.8C ( /P1 refers to flat rated to 30C),both at sea level as you already mentioned.

The highest available GEnx-1B rating on the B789 is the -1B76A/P2 (78,500Lbs). As previously mentioned above by another user, UA can cut GE and Boeing a check for the new FADEC rating plug and FCOM revision.

FYI, the highest thrust rating on the GEnx-1B is the -1B78/P2 (80,400Lbs).

Note, this rating is FAA certified since April 12, 2013. However it has yet to be certified on the 787-9 or even 787-10. In other words, while GE has long ago received FAA certification for the rating itself, Boeing has not yet received FAA certification for use the 787-9 or 787-10. This is current as of Sept. 11 2020. This does not rule out that certification of the -1B78/P2 on 787-9 or 787-10 is currently in process/pending.

I am not aware of any customer optioning their GEnx powered 787-9/10 with this rating and that would explain why Boeing has in turn not yet applied for and received FAA certification.

Is 1B76A/P2 flat rated to 32.8*C?

Okcflyer wrote:

Qantas744er wrote:

Some facts for a change:

UAL B789s are all powered by GEnx-1B74/75/P2 (76,600Lbs).

Small note Zeke: /P2 is flat rated to 32.8C ( /P1 refers to flat rated to 30C),both at sea level as you already mentioned.

The highest available GEnx-1B rating on the B789 is the -1B76A/P2 (78,500Lbs). As previously mentioned above by another user, UA can cut GE and Boeing a check for the new FADEC rating plug and FCOM revision.

FYI, the highest thrust rating on the GEnx-1B is the -1B78/P2 (80,400Lbs).

Note, this rating is FAA certified since April 12, 2013. However it has yet to be certified on the 787-9 or even 787-10. In other words, while GE has long ago received FAA certification for the rating itself, Boeing has not yet received FAA certification for use the 787-9 or 787-10. This is current as of Sept. 11 2020. This does not rule out that certification of the -1B78/P2 on 787-9 or 787-10 is currently in process/pending.

I am not aware of any customer optioning their GEnx powered 787-9/10 with this rating and that would explain why Boeing has in turn not yet applied for and received FAA certification.

Is 1B76A/P2 flat rated to 32.8*C?

It is. /P2 specifies the 32.8C flat rating and /P1 specifies a 30C flat rating.

Most GEnx-1B ratings now have /P2 as a option and some even as a standard (only option).

Qantas744er wrote:

Small note Zeke: /P2 is flat rated to 32.8C ( /P1 refers to flat rated to 30C),both at sea level as you already mentioned.

Not according to the TCDS when installed on the 787, where is your data from ?

zeke wrote:

Qantas744er wrote:

Small note Zeke: /P2 is flat rated to 32.8C ( /P1 refers to flat rated to 30C),both at sea level as you already mentioned.

Not according to the TCDS when installed on the 787, where is your data from ?

My apologies Zeke, I mixed up the GEnx-1 model designators. /P2 alone only refers to the second PiP
And /P1 to the first PiP.

The -76A/P2 is Flat rated to 32.8C as previously mentioned. While a -76/P2 is flat rated to the standard 30.0C.

You can verify the above in FAA TCDS 00078NE (GEnx-1B and -2B).

747classic wrote:

Qantas744er wrote:

zeke wrote:

Not according to the TCDS when installed on the 787, where is your data from ?

My apologies Zeke, I mixed up the GEnx-1 model designators. /P2 alone only refers to the second PiP
And /P1 to the first PiP.

The -76A/P2 is Flat rated to 32.8C as previously mentioned. While a -76/P2 is flat rated to the standard 30.0C.

You can verify the above in FAA TCDS 00078NE (GEnx-1B and -2B).

The -76/P2 has not to be certified (yet) at the 787-9 according the 787 TCDS (page 10/26), only the -76A/P2
On the 787-10 both are certified.

While absolutely correct, this only means that Boeing has not yet bothered to apply for FAA certification and receive the required TCDS revision/approval.

A paperwork exercise at best. Especially considering the only difference between a -76/P2 and -76A/P2 is a different FADEF plug.

If and when a customer options -76/P2 you’ll see it pop up on the TCDS.

Qantas744er wrote:

A paperwork exercise at best. Especially considering the only difference between a -76/P2 and -76A/P2 is a different FADEF plug.

You characterization of what is involved is far from correct, the GEnx--1B76/P2 and GEnx-1B76A/P2 were certified on May 17, 2018, they do however have lower electrical and hydraulic output, along with different temperature and rotational limits. When engine limits change, that changes aircraft limits, and results is far more analysis that you have tried to portray. Fact it its been more than 2 years since the GEnx--1B76/P2 and GEnx-1B76A/P2 was certified, and it is yet to make its way onto the airframe.

So much for a "paperwork exercise at best".

zeke wrote:

flipdewaf wrote:

The BLR route does throw up some interesting questions as it is indeed ~250nm further than the SFO sin route that struggled. My take here though is that whilst the two routes might superficially look similar the likely hood of encountering the winds that made the SFO-SIN route so difficult may well be very different.

I ran plans SFO-BLR and BLR-SFO, SFO-BLR carried around 34 tonnes, flight time 16:55, and the reverse same payload 16:40.

Hello Zeke & flipdewaf,
SEA is near my home and I pay close attention to international flights at that airport. AA has announced SEA-BLR so If you would, tell us what you think of SEA-BLR-SEA.
I've modified flipdewaf's link for SEA.

http://www.gcmap.com/mapui?P=SEA-BLR%2C ... =wls&DU=nm

Thanks,
Cary