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Channex757
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Re: Best Replacement Engines for the B52

Fri Sep 22, 2017 12:30 am

Interesting video report (annoying voiceover though)
https://www.youtube.com/watch?v=NrFk-H6Ai0M

Rolls is to bid with the BR725, or F130 as it's known locally, with a US finishing and test facility to be built.
 
SCAT15F
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Re: Best Replacement Engines for the B52

Tue Nov 07, 2017 3:10 am

That's strange, I thought earlier they were offering the BR715 which makes much more sense both in terms of fuel efficiency and thrust. The BR725 would actually offer less thrust than the TF-33 and higher fuel consumption than the BR715. The BR715's thrust margin would help with hot and hi too without pushing the engine so hard.
 
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Dutchy
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Re: Best Replacement Engines for the B52

Tue Nov 07, 2017 5:02 pm

Do they get a better fuel consumption with more trust? Seems like a no brainer for the BR715. Or doesn't the BR715 fit and the BR725 does? Or weight requirements etc.
 
LightningZ71
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Re: Best Replacement Engines for the B52

Tue Nov 07, 2017 9:20 pm

The BR725 is within an inch smaller than the tf33p3 in fan diameter, 700 lbs lighter, is rates for within 100 lbs/ft of thrust and is the most modern variant of the br700 family. It is as close to a drop in fit as you will find for the application . Even that being the case, it's FAR from a simple project. The interior of the nacelle will still need to be heavily reworked, the wings will need to be opened to run plenty of wires, as will the interior of the forward fuselage. The cockpit will require extensive modifications both for the pilots and engineer. And, if you are ripping all of that up, you might as well do the fatigue life limited wing panels while you are at it. And, this will have to include work done on spare frames as well.

Not cheap at all.
 
jupiter2
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Re: Best Replacement Engines for the B52

Wed Nov 08, 2017 2:36 am

LightningZ71 wrote:
The BR725 is within an inch smaller than the tf33p3 in fan diameter, 700 lbs lighter, is rates for within 100 lbs/ft of thrust and is the most modern variant of the br700 family. It is as close to a drop in fit as you will find for the application . Even that being the case, it's FAR from a simple project. The interior of the nacelle will still need to be heavily reworked, the wings will need to be opened to run plenty of wires, as will the interior of the forward fuselage. The cockpit will require extensive modifications both for the pilots and engineer. And, if you are ripping all of that up, you might as well do the fatigue life limited wing panels while you are at it. And, this will have to include work done on spare frames as well.

Not cheap at all.


Can they add a toilet while they're at it ?
 
DigitalSea
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Re: Best Replacement Engines for the B52

Wed Nov 08, 2017 4:45 am

Would there be a problem with increasing the size & durability of the landing gear to allow it to sit higher off the ground to accommodate different engines?
 
LightningZ71
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Re: Best Replacement Engines for the B52

Wed Nov 08, 2017 4:58 am

Yes, cost. Making any significant changes to the gears would involve a major tear-up of the belly and require a lot of internal rework to handle proper load distribution. At some point, it's cheaper to just build a new conventional bomber.
 
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AirlineCritic
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Re: Best Replacement Engines for the B52

Wed Nov 08, 2017 7:08 am

Is there no toilet on the B52? If true, that's amazing...
 
mmo
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Re: Best Replacement Engines for the B52

Wed Nov 08, 2017 1:09 pm

AirlineCritic wrote:
Is there no toilet on the B52? If true, that's amazing...


With over 2000 hours on the D/G/H. It is VERY TRUE!
 
angad84
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Re: Best Replacement Engines for the B52

Wed Nov 08, 2017 6:35 pm

mmo wrote:
AirlineCritic wrote:
Is there no toilet on the B52? If true, that's amazing...


With over 2000 hours on the D/G/H. It is VERY TRUE!

I'm going to have a word with the Bear pilots I know and tell them to STOP GRIPING ALREADY. Never realised the BUFF lacked a loo. Damn silly really.
 
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Revelation
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 1:55 am

Idlewildspotter wrote:
I believe the GE Passport BizJet Engine would be a wonderful replacement for the 8 Guzzling Tubes currently on the BUFF

SCAT15F wrote:
I never heard anything about the BR-725 being proposed.

Recent article at AvWeek: USAF Could Start Re-engining First Two B-52s By 2022 (free registration required) gives us lots of info from a recent conference at Barksdale:

• TF33 is not sustainable past 2030 due to obsolescence
• Another big issue is increased demands for electricity, up to 500 kVA
• Power demands come from modern weapons and fire control systems
• The aircraft will need an all-new power architecture too
• Program could cover 650 engines for the 72 aircraft fleet and for spares

and a lot more.

It ends with:

The leading candidates are Rolls-Royce’s 16,000 lb.-thrust BR725 and GE Aviation’s 18,000-lb.-thrust CF34-10.

Seems like the usual suspects smell blood and are circling the prey.

LightningZ71 wrote:
The BR725 is within an inch smaller than the tf33p3 in fan diameter, 700 lbs lighter, is rates for within 100 lbs/ft of thrust and is the most modern variant of the br700 family. It is as close to a drop in fit as you will find for the application . Even that being the case, it's FAR from a simple project. The interior of the nacelle will still need to be heavily reworked, the wings will need to be opened to run plenty of wires, as will the interior of the forward fuselage. The cockpit will require extensive modifications both for the pilots and engineer. And, if you are ripping all of that up, you might as well do the fatigue life limited wing panels while you are at it. And, this will have to include work done on spare frames as well.

Not cheap at all.

Indeed. As above, add to your list an all new power architecture, new fire control system and weaponry, etc.

Then ask where the money comes for this, B-22, F-35, KC-46A, etc.
 
mmo
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 7:30 am

Revelation....

Since you seem to be so pedantic, just wanted to clarify, there is HO fire control system on the H models. The vulcan cannon was removed several years ago. Also, could you tell us what the B-22 is? I must have missed that one. Do you mean the B-2 or the B-21?
 
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flyingturtle
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 10:19 am

AirlineCritic wrote:
Is there no toilet on the B52? If true, that's amazing...


Yes, they still have a simple bucket. This was also featured in http://www.bbc.com/news/magazine-33766644 .

In a Swiss bunker (built after 1950, to repel a possible Soviet invasion) I've seen a toilet seat mounted above a trash bag holder. I hope it was +/- airtight.............


LightningZ71 wrote:
the wings will need to be opened to run plenty of wires, as will the interior of the forward fuselage. The cockpit will require extensive modifications both for the pilots and engineer.


Wait - couldn't they put a little computer between cockpit and each engine, so that the computer translates all commands and signals in such a way that the modern engine is presented to the cockpit as an old TF-33?

David
 
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 1:07 pm

mmo wrote:
Revelation....

Since you seem to be so pedantic, just wanted to clarify, there is HO fire control system on the H models. The vulcan cannon was removed several years ago. Also, could you tell us what the B-22 is? I must have missed that one. Do you mean the B-2 or the B-21?

The fire control requirement is mentioned in the AvWeek article, and I too didn't understand why that was on the table.

The B-22 is a typo. I meant B-21 which is a program that one would think would be demanding a lot of funds at the same time this proposal would also need funding.

Thanks for your questions.
 
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 1:12 pm

flyingturtle wrote:
Wait - couldn't they put a little computer between cockpit and each engine, so that the computer translates all commands and signals in such a way that the modern engine is presented to the cockpit as an old TF-33?

I think developing, certifying, manufacturing and maintaining that translation interface is going to be more costly than just installing the new technology end to end.

As an engineer, pretty much every time I've taken the approach you are suggesting I've regretted it.

For instance, there's going to be a spamload of very useful information that a modern engine will generate, yet that info can't be passed via the TF-33's control mechanism.

You might as well just use the modern mechanism that's already ready to go, at the cost of having to redo the cockpit, which you'll want to do anyway to take advantage of the additional information.

Things are going to have to be torn down due to the uprated power production anyway so running the control paths for the engines should be relatively minor.
 
morrisond
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 8:12 pm

The B21 should be in production well before 2030 - just use the funds to build more of them or speed up production and stop putting more money into the B-52.

The TF-33 may not be sustainable for the full fleet after 2030 - but they should have enough parts or canabalize other planes to gradually retire them after 2030 - giving more time to build more B-21's.
 
mmo
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 8:49 pm

morrisond wrote:
The B21 should be in production well before 2030 - just use the funds to build more of them or speed up production and stop putting more money into the B-52.

The TF-33 may not be sustainable for the full fleet after 2030 - but they should have enough parts or canabalize other planes to gradually retire them after 2030 - giving more time to build more B-21's.



The problem is the decision to keep the BUFF in the inventory until the mid 2050s. The TF-33 will be unsustainable sometime after early 2020, which means there would be no more engines to cannibalize.
 
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flyingturtle
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Re: Best Replacement Engines for the B52

Thu Dec 28, 2017 9:48 pm

Revelation wrote:
For instance, there's going to be a spamload of very useful information that a modern engine will generate, yet that info can't be passed via the TF-33's control mechanism.


Well, can't they just use Wifi? :bouncy:

...anyway, re-engining those old and trusty bomb trucks isn't the most expensive thing for the USAF.


David
 
INFINITI329
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 8:37 am

According to Flightglobal the USAF will indeed seek to re-engine the B-52 as parts are beginning to dry up.

https://www.flightglobal.com/news/artic ... es-446745/
 
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Revelation
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 11:20 am

flyingturtle wrote:
Revelation wrote:
For instance, there's going to be a spamload of very useful information that a modern engine will generate, yet that info can't be passed via the TF-33's control mechanism.

Well, can't they just use Wifi? :bouncy:

...anyway, re-engining those old and trusty bomb trucks isn't the most expensive thing for the USAF.

David

If the C-5 re-engine is any clue, they'll find a way to make it expensive.
 
mmo
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 12:33 pm

Revelation wrote:
If the C-5 re-engine is any clue, they'll find a way to make it expensive.


IIRC, the C-5M program was more than just a re-engine program. Anyone who thinks the B-52 program will be be engines only is kidding themselves. There are major systems upgrades which will have to be accomplished. In addition, there are afrirame modifications and other mods necessary to keep the aircraft operational until the 2050s.
 
estorilm
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 1:18 pm

mmo wrote:
Revelation wrote:
If the C-5 re-engine is any clue, they'll find a way to make it expensive.


IIRC, the C-5M program was more than just a re-engine program. Anyone who thinks the B-52 program will be be engines only is kidding themselves. There are major systems upgrades which will have to be accomplished. In addition, there are afrirame modifications and other mods necessary to keep the aircraft operational until the 2050s.

Won't almost any new (modern) engine require FADEC? Or is it possible to revert an engine design to eliminate FADEC? Obviously this would require extensive re-wiring of the entire aircraft and cockpit, which I assume is already going to be required when going from 8x to 4x... actually damn my brain can't even comprehend the amount of changes that'll entail haha. This would almost certainly require an ENTIRE cockpit redesign essentially. :o
 
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 1:26 pm

mmo wrote:
Revelation wrote:
If the C-5 re-engine is any clue, they'll find a way to make it expensive.

IIRC, the C-5M program was more than just a re-engine program. Anyone who thinks the B-52 program will be be engines only is kidding themselves. There are major systems upgrades which will have to be accomplished. In addition, there are afrirame modifications and other mods necessary to keep the aircraft operational until the 2050s.

Well, after refreshing my memory, there was C-5 AMP ( mostly avionics ) followed by C-5 RERP ( engines, pylons, APUs, aiframe repairs/upgrades, etc ) to get to C-5M:

Following a study showing 80% of the C-5 airframe service life remaining,[96] Air Mobility Command (AMC) began an aggressive program to modernize all remaining C-5Bs and C-5Cs and many of the C-5As. The C-5 Avionics Modernization Program (AMP) began in 1998 and includes upgrading avionics to Global Air Traffic Management compliance, improving communications, new flat panel displays, improving navigation and safety equipment, and installing a new autopilot system. The first flight of a C-5 with AMP (85-0004) occurred on 21 December 2002.[97]

The Reliability Enhancement and Re-engining Program (RERP) began in 2006. It includes new General Electric F138-GE-100 (CF6-80C2) engines, pylons and auxiliary power units, upgrades to aircraft skin and frame, landing gear, cockpit and pressurization systems.[44][98] Each CF6 engine produces 22% more thrust (50,000 lbf or 220 kN),[99] providing a 30% shorter takeoff, a 38% higher climb rate to initial altitude, an increased cargo load and a longer range.[specify][44][100] Upgraded C-5s are designated C-5M Super Galaxy.[101]

Ref: https://en.wikipedia.org/wiki/Lockheed_ ... per_Galaxy

Last time around the new engines were used to get approval for a lot more needed but expensive upgrades. This time I think the same thing will happen with B-52. The problem was that the costs grew to the point where they could no longer afford to upgrade the original number of frames. I suspect the same will happen with B-52. Costs will grow, USAF will prefer a smaller number of more up-to-date B-52s. They won't add money to the program because by then the B-21 will be sucking down huge swaths of budget.
 
mmo
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 2:08 pm

estorilm wrote:
mmo wrote:
Revelation wrote:
If the C-5 re-engine is any clue, they'll find a way to make it expensive.


IIRC, the C-5M program was more than just a re-engine program. Anyone who thinks the B-52 program will be be engines only is kidding themselves. There are major systems upgrades which will have to be accomplished. In addition, there are afrirame modifications and other mods necessary to keep the aircraft operational until the 2050s.

Won't almost any new (modern) engine require FADEC? Or is it possible to revert an engine design to eliminate FADEC? Obviously this would require extensive re-wiring of the entire aircraft and cockpit, which I assume is already going to be required when going from 8x to 4x... actually damn my brain can't even comprehend the amount of changes that'll entail haha. This would almost certainly require an ENTIRE cockpit redesign essentially. :o


Not having a FADEC/EEC is several steps backwards. The engines will be kept at 8 as going to 4 would make the entire program so expensive it wouldn't be worth is. By staying at 8 you don't have to redesign the rudder to handle the yaw resulting from increased thrust and engine out situations. As it is, the H can just barely handle 4 out on one side with the current powered rudder.

There will be considerable rewiring to allow for new generators, pneumatics, hydraulic upgrade, ATM compatible flight deck and the list goes on and on.
 
mmo
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 2:13 pm

Revelation wrote:
mmo wrote:
Revelation wrote:
If the C-5 re-engine is any clue, they'll find a way to make it expensive.

IIRC, the C-5M program was more than just a re-engine program. Anyone who thinks the B-52 program will be be engines only is kidding themselves. There are major systems upgrades which will have to be accomplished. In addition, there are afrirame modifications and other mods necessary to keep the aircraft operational until the 2050s.

Well, after refreshing my memory, there was C-5 AMP ( mostly avionics ) followed by C-5 RERP ( engines, pylons, APUs, aiframe repairs/upgrades, etc ) to get to C-5M:

Following a study showing 80% of the C-5 airframe service life remaining,[96] Air Mobility Command (AMC) began an aggressive program to modernize all remaining C-5Bs and C-5Cs and many of the C-5As. The C-5 Avionics Modernization Program (AMP) began in 1998 and includes upgrading avionics to Global Air Traffic Management compliance, improving communications, new flat panel displays, improving navigation and safety equipment, and installing a new autopilot system. The first flight of a C-5 with AMP (85-0004) occurred on 21 December 2002.[97]

The Reliability Enhancement and Re-engining Program (RERP) began in 2006. It includes new General Electric F138-GE-100 (CF6-80C2) engines, pylons and auxiliary power units, upgrades to aircraft skin and frame, landing gear, cockpit and pressurization systems.[44][98] Each CF6 engine produces 22% more thrust (50,000 lbf or 220 kN),[99] providing a 30% shorter takeoff, a 38% higher climb rate to initial altitude, an increased cargo load and a longer range.[specify][44][100] Upgraded C-5s are designated C-5M Super Galaxy.[101]

Ref: https://en.wikipedia.org/wiki/Lockheed_ ... per_Galaxy

Last time around the new engines were used to get approval for a lot more needed but expensive upgrades. This time I think the same thing will happen with B-52. The problem was that the costs grew to the point where they could no longer afford to upgrade the original number of frames. I suspect the same will happen with B-52. Costs will grow, USAF will prefer a smaller number of more up-to-date B-52s. They won't add money to the program because by then the B-21 will be sucking down huge swaths of budget.


IIRC, the AMP and RERP were pretty much dove tailed together with the AMP being approved and funded first. The problem is if they don't approve quite a substantial work package, the upper skin fatigue problem will have the aircraft grounded by 2040. The USAF has stated publicly, many times, they intend to keep it around until the 2050s at least.

Hopefully the USAF will get the entire package priced out and approved rather than coming back with a tin cup in their hand year after year. If they can't have all of them done, it becomes problematic if it's even worth doing a part of the fleet.
 
estorilm
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 4:01 pm

mmo wrote:
estorilm wrote:
mmo wrote:

IIRC, the C-5M program was more than just a re-engine program. Anyone who thinks the B-52 program will be be engines only is kidding themselves. There are major systems upgrades which will have to be accomplished. In addition, there are afrirame modifications and other mods necessary to keep the aircraft operational until the 2050s.

Won't almost any new (modern) engine require FADEC? Or is it possible to revert an engine design to eliminate FADEC? Obviously this would require extensive re-wiring of the entire aircraft and cockpit, which I assume is already going to be required when going from 8x to 4x... actually damn my brain can't even comprehend the amount of changes that'll entail haha. This would almost certainly require an ENTIRE cockpit redesign essentially. :o


Not having a FADEC/EEC is several steps backwards. The engines will be kept at 8 as going to 4 would make the entire program so expensive it wouldn't be worth is. By staying at 8 you don't have to redesign the rudder to handle the yaw resulting from increased thrust and engine out situations. As it is, the H can just barely handle 4 out on one side with the current powered rudder.

There will be considerable rewiring to allow for new generators, pneumatics, hydraulic upgrade, ATM compatible flight deck and the list goes on and on.

Ah thanks, makes sense - and I now remember some of the engine talks many years ago about compatible small engines to keep it at 8x. :)

Still a bummer, my imagination automatically reverts to a future 4-engined B-52 it seems.
 
INFINITI329
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 7:22 pm

Assuming the engine count stays at 8, what engines would be contenders? The current engine, the Pratt & Whitney TF33-P-3/103 cranks out 17,000 lbs of thrust (each). As long as it is within design limitations, I could foresee the USAF targeting the 20,000 lbs of thrust neighborhood. The engines that pop into mind are the GE Passport and the Rolls Royce BR700.
 
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Re: Best Replacement Engines for the B52

Wed Mar 14, 2018 8:28 pm

INFINITI329 wrote:
Assuming the engine count stays at 8, what engines would be contenders? The current engine, the Pratt & Whitney TF33-P-3/103 cranks out 17,000 lbs of thrust (each). As long as it is within design limitations, I could foresee the USAF targeting the 20,000 lbs of thrust neighborhood. The engines that pop into mind are the GE Passport and the Rolls Royce BR700.

#61 above says:

The leading candidates are Rolls-Royce’s 16,000 lb.-thrust BR725 and GE Aviation’s 18,000-lb.-thrust CF34-10.
 
DigitalSea
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 3:57 am

If within Donald Trump's Presidency, we finally get to see a re-engined B-52, then God Bless him.
 
LightningZ71
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 5:51 am

The BR-725 is essentially software upgradeable to higher thrust levels.

Here's a recent article on the whole project...
https://www.defensenews.com/air/2017/12 ... placement/
 
Andre3K
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 6:20 am

One thing is for certain, even though he loved the RR engines on his old 757, as you can see with the steel and aluminum duties he is all about protecting jobs here in the US. So more than likely it will go to GE. I'm not saying its impossible for RR to get it, but if they do then I think a concession would have to be producing them here (assuming they aren't already).
 
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 11:03 am

DigitalSea wrote:
If within Donald Trump's Presidency, we finally get to see a re-engined B-52, then God Bless him.

For God So Loved The Earth, He Gave Us The B-52 Bomber With New And Improved Engines.

Actually it's the US Congress (a God-less organization if I ever saw one) who will decide, and the US taxpayers who will pay.

Actually it's the Chinese who buy US debt who are paying.
 
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Phosphorus
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 5:00 pm

Politics aside, how would D-436 from Motor Sich stack up, performance-wise? Diameter looks right, for one thing.
 
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ikolkyo
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 5:23 pm

I think 4 GE9Xs would be great for the B52, sure would be a sight to see.
 
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ikolkyo
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 7:47 pm

Phosphorus wrote:
ikolkyo wrote:
I think 4 GE9Xs would be great for the B52, sure would be a sight to see.

8 engines it was, and 8 engines it is. The experts have delivered their verdict (and it's available on this very forum) -- rudder authority of B-52H is insufficient in multiple scenarios (especially takeoff), where asymmetrical thrust is resulting from loss of an engine, were B-52H to be powered by four large engines, vs eight smaller ones.


It was just a joke because of how absurd the GE9X would look on the B-52, but hey 8 of them would be a sight also!
 
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Phosphorus
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 7:48 pm

ikolkyo wrote:
I think 4 GE9Xs would be great for the B52, sure would be a sight to see.

8 engines it was, and 8 engines it is. The experts have delivered their verdict (and it's available on this very forum) -- rudder authority of B-52H is insufficient in multiple scenarios (especially takeoff), where asymmetrical thrust is resulting from loss of an engine, were B-52H to be powered by four large engines, vs eight smaller ones.
 
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Re: Best Replacement Engines for the B52

Thu Mar 15, 2018 9:57 pm

LightningZ71 wrote:
The BR-725 is essentially software upgradeable to higher thrust levels.

Here's a recent article on the whole project...
https://www.defensenews.com/air/2017/12 ... placement/


I cannot quite imagine B52 running the BR725. No smoke trails, and no screeching loud noise. I imagine it will go a lot further too on those engines too.
 
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Re: Best Replacement Engines for the B52

Fri Mar 16, 2018 4:45 am

ikolkyo wrote:
Phosphorus wrote:
ikolkyo wrote:
I think 4 GE9Xs would be great for the B52, sure would be a sight to see.

8 engines it was, and 8 engines it is. The experts have delivered their verdict (and it's available on this very forum) -- rudder authority of B-52H is insufficient in multiple scenarios (especially takeoff), where asymmetrical thrust is resulting from loss of an engine, were B-52H to be powered by four large engines, vs eight smaller ones.


It was just a joke because of how absurd the GE9X would look on the B-52, but hey 8 of them would be a sight also!

Well, an early proposal for the E-3 had 8 TF-34s instead of the JT-3Ds to ensure enough generators... stranger things have been proposed.
 
estorilm
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Re: Best Replacement Engines for the B52

Fri Mar 16, 2018 1:45 pm

ikolkyo wrote:
Phosphorus wrote:
ikolkyo wrote:
I think 4 GE9Xs would be great for the B52, sure would be a sight to see.

8 engines it was, and 8 engines it is. The experts have delivered their verdict (and it's available on this very forum) -- rudder authority of B-52H is insufficient in multiple scenarios (especially takeoff), where asymmetrical thrust is resulting from loss of an engine, were B-52H to be powered by four large engines, vs eight smaller ones.


It was just a joke because of how absurd the GE9X would look on the B-52, but hey 8 of them would be a sight also!

Why 4?

Wouldn't a single engine be nearly the same as all 8? :lol:

I think two GE9X's would give you like an additional 70% thrust. :o
 
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AirlineCritic
Posts: 1815
Joined: Sat Mar 14, 2009 1:07 pm

Re: Best Replacement Engines for the B52

Fri Mar 16, 2018 8:21 pm

Single engine? I'd love to see that as a picture!
 
LightningZ71
Posts: 688
Joined: Sat Aug 27, 2016 10:59 pm

Re: Best Replacement Engines for the B52

Sat Mar 17, 2018 6:24 am

cpd wrote:
LightningZ71 wrote:
The BR-725 is essentially software upgradeable to higher thrust levels.

Here's a recent article on the whole project...
https://www.defensenews.com/air/2017/12 ... placement/


I cannot quite imagine B52 running the BR725. No smoke trails, and no screeching loud noise. I imagine it will go a lot further too on those engines too.


I think I remember reading somewhere that, with the same fuel load, a BR725 equipped B-52 would have roughly a 30-40% greater range / loiter time. The BR725 actually weighs a bit less than the TF-34s, by about 1000 lbs or so, which means that if it isn't otherwise constrained, it could carry 4 more tons of fuel with the same payload mass, resulting in perhaps up to 50% more range. With one refueling from a very safe distance, it is essentially a single refuel global striker, and even with no refuel, for a precision war load, it can essentially get anywhere it needs to from the existing US bases without needing to hit a tanker first.
 
Nicoeddf
Posts: 1298
Joined: Thu Jan 10, 2008 7:13 am

Re: Best Replacement Engines for the B52

Sat Mar 17, 2018 7:31 am

LightningZ71 wrote:
cpd wrote:
LightningZ71 wrote:
The BR-725 is essentially software upgradeable to higher thrust levels.

Here's a recent article on the whole project...
https://www.defensenews.com/air/2017/12 ... placement/


I cannot quite imagine B52 running the BR725. No smoke trails, and no screeching loud noise. I imagine it will go a lot further too on those engines too.


I think I remember reading somewhere that, with the same fuel load, a BR725 equipped B-52 would have roughly a 30-40% greater range / loiter time. The BR725 actually weighs a bit less than the TF-34s, by about 1000 lbs or so, which means that if it isn't otherwise constrained, it could carry 4 more tons of fuel with the same payload mass, resulting in perhaps up to 50% more range. With one refueling from a very safe distance, it is essentially a single refuel global striker, and even with no refuel, for a precision war load, it can essentially get anywhere it needs to from the existing US bases without needing to hit a tanker first.


Sounds pretty attractive as a package if you ask me.
 
rlwynn
Posts: 1570
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Re: Best Replacement Engines for the B52

Sat Mar 17, 2018 7:40 pm

Why not a new order for new TF33s. There is nothing wrong with them outside that they are old and the is not the big supply of new parts. PW couls easily do it.
 
rlwynn
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Re: Best Replacement Engines for the B52

Sat Mar 17, 2018 7:48 pm

Why not a new order for new TF33s. There is nothing wrong with them outside that they are old and the is not the big supply of new parts. PW couls easily do it.
 
Buckeyetech
Posts: 229
Joined: Wed Jul 03, 2013 1:11 am

Re: Best Replacement Engines for the B52

Sat Mar 17, 2018 9:10 pm

As a former B-52 mechanic, I can tell you, new engine cowling alone would be worth their weight in gold to the maintainers. The current ones were over-engineered, and so difficult to rig once you tried to cannabalize it to another aircraft.
 
Ozair
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Re: Best Replacement Engines for the B52

Mon Jun 18, 2018 10:28 pm

Pratt & Whitney leaning towards PW815 for B-52 re-engining

Pratt & Whitney is leaning towards offering its PW815 engine for the US Air Force’s (USAF’s) highly-anticipated Boeing B-52 Stratofortress bomber re-engining programme, according to a key executive.

“Our primary focus is TF33 sustainment,” Pratt & Whitney military engines president Matthew Bromberg told Jane’s on 12 June at parent company United Technology Corp’s (UTC’s) digital accelerator tech hub in the Dumbo neighbourhood of Brooklyn. “That being said, we think the PW815 is a very compelling engine.”

http://www.janes.com/article/81129/prat ... e-engining
 
Andre3K
Posts: 360
Joined: Tue May 30, 2017 10:11 pm

Re: Best Replacement Engines for the B52

Tue Jun 19, 2018 1:07 am

Ozair wrote:
Pratt & Whitney leaning towards PW815 for B-52 re-engining

Pratt & Whitney is leaning towards offering its PW815 engine for the US Air Force’s (USAF’s) highly-anticipated Boeing B-52 Stratofortress bomber re-engining programme, according to a key executive.

“Our primary focus is TF33 sustainment,” Pratt & Whitney military engines president Matthew Bromberg told Jane’s on 12 June at parent company United Technology Corp’s (UTC’s) digital accelerator tech hub in the Dumbo neighbourhood of Brooklyn. “That being said, we think the PW815 is a very compelling engine.”

http://www.janes.com/article/81129/prat ... e-engining


Kind of an odd choice, because unless the PW815 is derated for the G600 and really has more thrust, they will lose a significant amount of thrust (just under 16,000lb for the PW815 vs over 17,000 for the TF33)
 
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Francoflier
Posts: 6554
Joined: Wed Oct 31, 2001 12:27 pm

Re: Best Replacement Engines for the B52

Tue Jun 19, 2018 6:52 am

The PW800 series is apparently designed for up to 20klbs. Not sure how much the 815 is flat rated to, but I doubt they'd have any trouble extracting 17k out of it, especially in military specs.
Not to mention that the TF33 only gives 17k at ISA, whereas the 815 is probably able to provide rated thrust to above ISA +15.

I'm sure it would be a great fit... If they EVER get to finally re-engine the B-52.
:sigh:
 
DavidMHoffman
Posts: 1
Joined: Wed Jul 18, 2018 5:02 pm

Re: Best Replacement Engines for the B52

Wed Jul 18, 2018 5:23 pm

rlwynn wrote:
Why not a new order for new TF33s. There is nothing wrong with them outside that they are old and the is not the big supply of new parts. PW couls easily do it.


That does nothing to lower per flight hour or per ton-mile maintenance costs or reduce per ton-mile fuel consumption.
 
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Tugger
Posts: 12765
Joined: Tue Apr 18, 2006 8:38 am

Re: Best Replacement Engines for the B52

Wed Jul 18, 2018 7:05 pm

DavidMHoffman wrote:
rlwynn wrote:
Why not a new order for new TF33s. There is nothing wrong with them outside that they are old and the is not the big supply of new parts. PW couls easily do it.


That does nothing to lower per flight hour or per ton-mile maintenance costs or reduce per ton-mile fuel consumption.

:checkmark:
If a program can cover it own costs with savings it produces, it makes it a better budget tool for the service.

Tugg

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