Boeing B-52 Re-engine News and Discussion Thread

744SPX · Fri Jan 08, 2021 6:23 am

Despite the RR renders showing their engine inside the existing nacelles, I think when they say "use the same nacelle" it means just the pylon and nacelle substructure. The only one of these engines that even has a bypass duct like the TF-33 is the CF-34, and its length is different. The actual engine "pods" will have to be changed or there will be serious aerodynamic penalties.

texl1649 · Fri Jan 08, 2021 11:53 am

The RR image seems to show the fan using the bypass duct as is to me?

https://www.rolls-royce.com/products-an ... /f130.aspx

Clearly not an engineering drawing but I am curious what our engine experts on a.net have to say about it.

VMCA787 · Fri Jan 08, 2021 12:08 pm

Part of the re-engine package is the inclusion of new nacelles. IIRC, that part of the contract has already been awarded to Boeing in the form of the integration of the CERP.

bikerthai · Fri Jan 08, 2021 1:27 pm

texl1649 wrote:
The RR image seems to show the fan using the bypass duct as is to me?

All the new engine should have a by-pass duct. If you want to keep the same pod diameter, you will have to increase the ratio of the by-pass diameter vs the core/hi-pressure stages to get your efficiency improvements.

You can also increase efficiency by improving the blades and stator, but the lowest hanging fruit is the fan/core ratio.

bt

texl1649 · Fri Jan 08, 2021 6:21 pm

bikerthai wrote:
texl1649 wrote:
The RR image seems to show the fan using the bypass duct as is to me?

All the new engine should have a by-pass duct. If you want to keep the same pod diameter, you will have to increase the ratio of the by-pass diameter vs the core/hi-pressure stages to get your efficiency improvements.

You can also increase efficiency by improving the blades and stator, but the lowest hanging fruit is the fan/core ratio.

bt

I would guess this is confidential as to the fan size/adjustments they deem optimal for the situation/mission (part of the reason the RR image is clearly just notional/PR), but none of the other vendors are saying they can use the same pod/nacelle either. No doubt some nacelle weight/CG adjustments will have to be validated.

bikerthai · Fri Jan 08, 2021 8:13 pm

Personally, I feel if they are to have new engines, best solution is to get new nacelles.

Those old nacelles are probably made of metal and weighs a ton. A modern composite nacelle design would save a lot of weight and should be worth the additional cost.

bt

Buckeyetech · Fri Jan 08, 2021 8:18 pm

bikerthai wrote:
Personally, I feel if they are to have new engines, best solution is to get new nacelles.

Those old nacelles are probably made of metal and weighs a ton. A modern composite nacelle design would save a lot of weight and should be worth the additional cost.

bt

I turned wrenches for 3 years on the H models, and trust me those old nacelles were the most frustrating part of the job. The lower body cowl’s latches are over engineered, which in turn caused hundreds of man hours fixing the sheet metal on them due to canabalizing off of other aircraft.

VMCA787 · Fri Jan 08, 2021 9:21 pm

As I wrote previously, new nacelles are part of the integration package which has already been awarded to Boeing.

LyleLanley · Fri Jan 08, 2021 9:27 pm

Are they expecting to keep the wing drop tanks with the reengine program? I vaguely remember something about those tanks being kept full and mostly unused for CG, but possibly being replaced with jammers or some other equipment.

texl1649 · Fri Jan 08, 2021 9:32 pm

The tanks are a fair question. The new engines themselves will be heavier, but wing flex in flight (upward) I would think would also add more stress to the wing upper surface (a primary area of long term concern).

rlwynn · Fri Jan 08, 2021 10:15 pm

The new engines will be lighter.

VMCA787 · Sat Jan 09, 2021 6:08 am

LyleLanley wrote:
Are they expecting to keep the wing drop tanks with the reengine program? I vaguely remember something about those tanks being kept full and mostly unused for CG, but possibly being replaced with jammers or some other equipment.

On the H model, the tanks will stay. They were modified on the G/H models to take care of wing flutter. They are used for fuel when the fuel sequence is such that the fuel is mains to the engine and the main tanks are down to a certain fuel level. There is no ECM or anything else. On other models, such as the D the external tanks were actually jettisonable and there was a parachute in the aft end of the tank.

889091 · Sat Jan 09, 2021 11:57 am

Will cartridge starts still be possible?

bikerthai · Sat Jan 09, 2021 2:51 pm

Why not an electric starter like on the 787? Fewer parts as starter/generator should be already on the engine. Just need a good battery to kick off that first engine. Does the 52 have an apu?

bt

bikerthai · Sat Jan 09, 2021 3:05 pm

I guess it doesn't have an APU as an article I just looked up suggests they can put one where the tail gun used to be. This is not a good idea as the complexity of running fuel to that location will cause more headaches than its worth.

On the other hand, a battery would be less complicated. Although the weigh of the power cable need to go from the battery to that first engine would suggest the best place to put the battery would be somewhere near the wing box or the power distribution bus.

bt

LyleLanley · Sun Jan 10, 2021 12:26 am

Thanks for that. Any word on if they’ll still be fuel tanks (probably less needed with re-engine) or replaced with equipment pods? That’s a lot of real estate to play with in an airframe that provides persistence over the battlespace - thinking of the pods on the U-2.

VMCA787 · Sun Jan 10, 2021 8:22 am

They will continue to be fuel pods. As I wrote previously, "drop tanks" are for wing flutter and are emptied at certain weights. If they were to remain as structure new wing flutter tests would have to be accomplished.

One good thing about the Buff is there is an excess of space to mount all sorts of equipment. The limiting factor had been electrical generation. However, the CERP will solve that problem by adding 4 generators and replacing the existing generators with lower-powered ones but having 8 total resulting in greater power availability.

LyleLanley · Sun Jan 10, 2021 3:41 pm

VMCA787 wrote:
They will continue to be fuel pods. As I wrote previously, "drop tanks" are for wing flutter and are emptied at certain weights. If they were to remain as structure new wing flutter tests would have to be accomplished.

One good thing about the Buff is there is an excess of space to mount all sorts of equipment. The limiting factor had been electrical generation. However, the CERP will solve that problem by adding 4 generators and replacing the existing generators with lower-powered ones but having 8 total resulting in greater power availability.

Ah, that makes sense. Thanks for clarifying the wing flutter with structure vs empty tanks.

Considering how many times the B-52 has been reimagined over its lifespan already, I’m anxious to see how the increased loiter, electrical power, and digital architecture will change their capes and TTPs. Especially with regards to crew dynamics and blurring the lines between the pilots, offensive, and defensive teams.

VMCA787 · Sun Jan 10, 2021 3:56 pm

LyleLanley wrote:
Ah, that makes sense. Thanks for clarifying the wing flutter with structure vs empty tanks.

Considering how many times the B-52 has been reimagined over its lifespan already, I’m anxious to see how the increased loiter, electrical power, and digital architecture will change their capes and TTPs. Especially with regards to crew dynamics and blurring the lines between the pilots, offensive, and defensive teams.

To be honest, the biggest problem is the wiring and the wiring harnesses. The aircraft has been modified so many times it's a mess. I flew the D/G model and it could be a nightmare. When I flew the D, the D-BNS had just been installed and it was a great system but there were gremlins all over the place.

I think the crew issues will be minor as you have the B-1 and B-2 with smaller crews. What will be interesting is if AAC moves forward and eliminates the Nav position and has the RN take up that slack. In addition to the new radar, there must be a rethink of the NAV/BNAV system in the background. Just from an ergonomic perspective, have one person do both tasks will be very difficult downstairs.

The CERP will have generators on all engines of around 65Kva/engine (520Kva total) compared with around 450 Kva currently. With one gen out that leaves 455Kva compared with 338Kva. So that is a change that is long overdue.

LightningZ71 · Mon Jan 11, 2021 12:29 am

I am of the opinion that the total of 520Kva will turn out to be insufficient in the near future. With defensive systems on the airframe being very likely to include dire ted energy systems like high powered laser dazzlers for IR seeking missiles and even stronger defensive ECM levels, not to mention the possibility of actual defensive laser weapons that feel like they have been forever in development that will be in the 100s of KW strength to be effective, that seems to be precious little available power.

VMCA787 · Mon Jan 11, 2021 7:19 am

LightningZ71 wrote:
that seems to be precious little available power.

Of course, you do realize they can install higher rated generators, don't you? Currently, there is a problem if you lose one generator. You still have enough power to run everything but it gets real close to what is available. To be honest, I doubt you will see directed energy weapons on the Buff. However, it already has one!!??

LightningZ71 · Mon Jan 11, 2021 2:17 pm

Oh, I have no doubts that the generators can be upgraded at a later date. However, we all know that that's also going to turn into another multi-million dollar project with years of lead time, tons of development money, cost overruns, etc. Why not add what should be a trivial bit of future proofing to the current program by speccing generators with, and this is just a shot in the dark, 20% more generator capacity per engine? Another 100KVA total per airframe - 12-13 per engine, won't make the generators prohibitively more expensive nor significantly larger and heavier.

I get it though, feature creep is a big deal, and this game can be chased forever. What they are getting is already an upgrade over what they had, and the new setup allows more failure margin.

bikerthai · Mon Jan 11, 2021 3:18 pm

LightningZ71 wrote:
speccing generators with, and this is just a shot in the dark, 20% more generator capacity per engine?

This was done with the P-8A program. Although not sure how much excess capacity. The excess capacity allowed them to add the AAS Radar later on.

bt

bikerthai · Mon Jan 11, 2021 5:08 pm

LightningZ71 wrote:
Another 100KVA total per airframe - 12-13 per engine, won't make the generators prohibitively more expensive nor significantly larger and heavier.

For reference, the P-8A has more powerful generators than a standard 737NG. However I do not believe it got bigger. I think they increased the power by increasing the copper winding.

As a benefit, more powerful generators means more powerful starters to kick those engines on.

bt

texl1649 · Sat Feb 20, 2021 2:50 pm

Loren Thompson has an utterly absurd piece out about how the CF-34 is at risk to Chinese espionage because it’s being used on the ARJ-21. I’m not sure any of the engines (all use FADEC) would have some sort of top secret controls which if the Chinese are real interested they won’t get their hands on the design/algorithms.

https://www.forbes.com/sites/lorenthomp ... a3bbda645b

bikerthai · Sat Feb 20, 2021 4:43 pm

Your right.
His premises is the FADEC system may be prone to hacking would mean that the Chinese would have to hack into the plane's computer network before they can actually exploit the FADEC weakness.

If they manage get pass the firewall, they have better things to do than mess around with FADEC.

Imagine the protential of the Chinese hacking into the P-8A because of all the 737NG flying with FADEC for the Chinese Airlines.

bt

JayinKitsap · Tue Apr 13, 2021 11:13 pm

It isn't the engines but another piece of the B-52 upgrades has been placed. Collins doing brakes and landing gear changes.

https://www.daytondailynews.com/local/a ... FP7SLH544/

VMCA787 · Fri May 28, 2021 7:44 pm

Interesting numbers in the proposed DOD budget for 2022. The B-52 sees funding increase from $483 million to $716 million. The interesting tidbit is the remarks about keeping the B-52 flying through 2050. Fairly deep cuts proposed for the C-130, KC-135R/T receiver capable tankers, A-10, F-15C/D, F-16C/D and others.

https://www.defenseone.com/policy/2021/ ... ts/174389/

Djlorry3 · Sat May 29, 2021 8:42 am

VMCA787 wrote:
Interesting numbers in the proposed DOD budget for 2022. The B-52 sees funding increase from $483 million to $716 million. The interesting tidbit is the remarks about keeping the B-52 flying through 2050. Fairly deep cuts proposed for the C-130, KC-135R/T receiver capable tankers, A-10, F-15C/D, F-16C/D and others.

https://www.defenseone.com/policy/2021/ ... ts/174389/

Engine replacement and new radar are confirmed, too.
They wrote:

One exception to the downsizing is one of the service’s oldest platforms, the B-52. If the Air Force’s plan holds, it will mean the military has relied on that airframe for almost 100 years.

Funding for the Cold War-era strategic bomber would increase from $483 million in 2021 to $716 million in 2022 to support “the most comprehensive modernization of the B-52 in its history, including new engines and radar systems,” the Air Force wrote. “These efforts will extend this 1950s-era bomber as a credible deterrent through 2050.”

LightningZ71 · Mon May 31, 2021 1:33 am

That would be incredible. Can you imagine the look on the face of the chief designer on the B-52 if you told him, on the first day of the project, that versions of his design would be flying one hundred years in the future?

Phosphorus · Mon May 31, 2021 7:24 am

LightningZ71 wrote:
That would be incredible. Can you imagine the look on the face of the chief designer on the B-52 if you told him, on the first day of the project, that versions of his design would be flying one hundred years in the future?

Doubling down -- can you imagine the look on his face, if (after his initial surprise wears off a little) you tell him that actual production would wrap up within a decade from the first flight, and this "hundred years of flying" would be done by planes, built within that time frame?

bikerthai · Mon May 31, 2021 12:56 pm

What was the last weapon system to have been in active military for a 100 years? The musket? The Navy revolver? The saber?

bt

mxaxai · Mon May 31, 2021 2:17 pm

bikerthai wrote:
What was the last weapon system to have been in active military for a 100 years? The musket? The Navy revolver? The saber?

bt

The advance of technology and tactics even in ancient times meant that most weapons would become obsolete over a 100 year span. While the concept of a musket or saber is simple and centuries old, people would regularly add small improvements. Additionally, firearms face wear and tear from each shot. So I doubt that any individual weapon lasted for 100 years. Your best bet would probably be naval cannons since they were expensive to make and require little maintenance. Especially shore batteries, which saw little action unless the specific place they were guarding was attacked.

Phosphorus · Mon May 31, 2021 3:51 pm

M1911 (a.k.a. Colt 1911, designed by John Browning), is still in front-line military use, 110 years now. Admittedly, US Army & Co dropped it as a standard side-arm in 1980's, but there are other US govt agencies still using it. Of course, multiple armed forces worldwide still use it.

Nomadd · Mon May 31, 2021 4:44 pm

The M2 .50 caliber isn't far behind. It hasn't changed much in 88 years.

prebennorholm · Mon May 31, 2021 11:45 pm

Swiss army bicycle type MO-05 was produced basically unchanged from 1905 to 1993. Only from 1946 and onwards the frame was made of thinner but stronger steel reducing weight from approximately 52 to 48 lbs.

It is still being used, although not any longer as a weapon carrier, only as a personal transport, As carrier of panzerfaust (bazooka). machine gun etc. it has gradually been replaced by model MO-93 and MO-12 (design 1993 and 2012) which both are updated with modern features such as multiple gear systems.

bikerthai · Tue Jun 01, 2021 4:26 am

prebennorholm wrote:
Swiss army bicycle

Made my day. At one time the US army was testing the Montague Folding bike for their paratroopers.

Not sure what became of that.

bt

bikerthai · Tue Jun 01, 2021 4:30 am

I guess if you eliminate the tech improvement, then the English long bow probably was effective for a long time with minimal changes.

bt

JayinKitsap · Sat Jun 05, 2021 3:27 am

bikerthai wrote:
prebennorholm wrote:
Swiss army bicycle

Made my day. At one time the US army was testing the Montague Folding bike for their paratroopers.

Not sure what became of that.

bt

So does it transform into a knife?

bikerthai · Sat Jun 05, 2021 4:06 am

It transformed into a suit case, so airlines didn't charge me $50 to check in my bike. That was when we could check in 2 suit case for free!

bt

SteelChair · Sun Jun 06, 2021 12:49 pm

I vote for the GTF. Imagine the range increase.

Buckeyetech · Fri Jun 18, 2021 12:17 pm

The engines likely will never be removed from their wings because the aircraft are expected to retire before the engines need an overhaul.

Nice tidbit. The number of engine mechanics at Minot and Barksdale will go down about 90% if true. I wouldn’t put it past the USAF to make engine maintenance way harder than it needs to be though….

https://www.airforcemag.com/b-52-engini ... realities/

Sooner787 · Fri Jun 18, 2021 9:38 pm

If the new administration passes this latest $6 Trillion Infrastructure bill
they're salivating over, I fear those funds will come from all the big ticket
items the Pentagon is planning on, like the new B-21, this B-52 NEO proposal,
and the future CVN-81 as well as F-35 procurement.

CRJockey · Fri Jun 18, 2021 10:44 pm

Sooner787 wrote:
If the new administration passes this latest $6 Trillion Infrastructure bill
they're salivating over, I fear those funds will come from all the big ticket
items the Pentagon is planning on, like the new B-21, this B-52 NEO proposal,
and the future CVN-81 as well as F-35 procurement.

And it might well serve the nation better than more military toys.

744SPX · Sun Jun 20, 2021 3:23 am

CRJockey wrote:
Sooner787 wrote:
If the new administration passes this latest $6 Trillion Infrastructure bill
they're salivating over, I fear those funds will come from all the big ticket
items the Pentagon is planning on, like the new B-21, this B-52 NEO proposal,
and the future CVN-81 as well as F-35 procurement.

And it might well serve the nation better than more military toys.

Couldn't agree more, and I say that as a Navy vet.

art · Wed Jun 23, 2021 3:45 pm

June 21/21: Expensive Re-Engine The US Air Force has revised external link upwards the money required to re-engine the B-52H bomber. The program will now cost $11 billion.

https://www.defenseindustrydaily.com/up ... ion-06583/

JayinKitsap · Sun Aug 15, 2021 11:25 pm

A little bird might be talking in background that the award for this phase is approaching. In early summer there were reports the program cost was rising by like 9%, probably fed by the review of the proposals, etc. I can't find any formal information as to award dates, etc. In today's market an order for 608 engines looks quite good. The spread in Air Force magazine appears to be PW PR, one last nudge to the committee to "pick me! pick me!".

https://www.airforcemag.com/pratt-whitn ... -the-b-52/

https://www.flyingmag.com/story/aircraf ... ep-flying/

https://www.defenseone.com/technology/2 ... ay/182687/

https://insidedefense.com/daily-news/ai ... ent-summer

744SPX · Thu Sep 02, 2021 1:41 am

This is the closest I've seen yet to actual nacelle renders with the new engines. The CF-34's nacelles look hideous! The video also reveals the CF-34 to have drastically inferor sfc compared to the Passport.

https://www.geaviation.com/military/eng ... qcQAvD_BwE

BestIntellect · Sat Sep 04, 2021 5:03 pm

744SPX wrote:
This is the closest I've seen yet to actual nacelle renders with the new engines. The CF-34's nacelles look hideous! The video also reveals the CF-34 to have drastically inferor sfc compared to the Passport.

https://www.geaviation.com/military/eng ... qcQAvD_BwE

I don't see anything close to a finalized nacelle design anywhere in that.

par13del · Wed Sep 08, 2021 1:04 pm

A couple of my concerns, not much discussion on metal fatigue on the BUFF but plenty on other a/c, the frames are old, real old.
Secondly, how is this two bomber thought any different from what was done previously with the B1, cancelled then restarted and never purchased in sufficient quantity to retire the B-52, then the B2, once again never purchased in sufficient quantity, now we are absolutely sure that the new bomber will not have any issues which run's it off the financial rails that they will end up with a fleet size similar to the B2.
Perhaps the funds they are thinking of spending to re-engine the B-52 should be spent hiring auditors and forensic accountant's to ensure the new bomber stays on track and within budget.

Who is online

Popular Searches On Airliners.net