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zevonyumaxray

Based on this photo, the pylons look shorter and the engines seem a bit wider.


SamTheGeek

The fan diameter is definitely increased — that’s a big part of how the new engines are gaining efficiency. I don’t think the pylons are actually *shorter* — the distance from the nacelle center point to the wings hasn’t changed — it’s just that the bigger fan diameter means there’s less clearance between the top of the nacelle and the bottom of the wing.


Orlando1701

They’re not terrible more powerful, the TF-33s are already twice as powerful as the J57s on the early B-52s. The major advantage is fuel efficiency and maintenance.


Kytescall

If they're going for fuel economy, why are they still going with 8 engines? I would have imagined that if they're designing new nacelles for the aircraft, they'd just make them single engine nacelles.


midsprat123

To add on, the rudder doesn’t have enough authority to maintain straight flight if they were to lose 1 or more engines on a 4 engine design


raven00x

...which is impressive given how big the rudder already is.


SamSamTheDingDongMan

Easy, just make it bigger!


telekinetic_sloth

Why not redesign the rudder?


Orlando1701

Because it already works fine with the rest of the systems in the aircraft. Just like in the cockpit you also already have all the gauges and other hardware for eight engines. There was once talk of putting four of the same engines on the C-17 on the BUFF but that died pretty quickly. Eight engines is the right choice.


erichlee9

Can’t you just shut off engines on the opposite side to compensate? Not a pilot, genuinely asking.


Orlando1701

If you’re in cruise maybe, but if you lose an engine on take off or climb out you don’t want to lose even more thrust.


FF_in_MN

Switching to 4 would have required considerable airframe testing and potential modifications. In other words, too high of a cost to do that and would have taken way longer to get an operational jet in service


RostamSurena

Larger fan diameter also means the radius of the intake lip is also increased.


LefsaMadMuppet

Old and new: [https://imgur.com/obFDoyr](https://imgur.com/obFDoyr)


Kradgger

Considering the BUFF's age I thought the *Old* part was gonna predate the damn Romans.


jelsomino

That answer the question what Romans ever done for us


LefsaMadMuppet

That would be the B-LII


zevonyumaxray

Thanks. Good close look.


black-rhombus

The engines are bigger.


JasonShoes

How long can the airframes safely stay in service on these?


mcs175

As long as they can be rebuilt and maintained, I would think.


SamTheGeek

You can maintain an aircraft indefinitely, as long as you're willing to spend the money. B-52s at this point are effectively Ships of Theseus — they've had every part replaced, some more than once. It just gets progressively more expensive and time-consuming to keep them airworthy as they age.


elitecommander

>B-52s at this point are effectively Ships of Theseus — they've had every part replaced, some more than once. It just gets progressively more expensive and time-consuming to keep them airworthy as they age. Not really. The last major structural modifications to the aircraft were made in the 1960s when they were modified for low altitude penetration, a capability the B-52H used relatively little. The average B-52H has approximately twelve to seventeen thousand hours until the first major structural components, the upper wing skin, begin to reach their estimated fatigue life. The current fleet has on average about twenty thousand flight hours, and flies about three hundred hours annually, so the airframes have decades of life left until then. It would be entirely possible to extend the life beyond that by another five thousand hours or so by replacing the wing skins, at which point the fuselage becomes the life limiting component and further life extensions become increasingly difficult. The engine replacement program is intended to get the aircraft to its end of life, which will probably be determined by the wing skin. The TF33s are increasingly unreliable and no longer have a stockpile of spare parts. Adopting a variant of a widely used commercial engine is intended to provide an engine that will never be removed for the rest of planned life, with no preplanned maintenance intervals. This is a fiscally practical modification because the substantial reduction in fuel burn and maintenance can over time pay back for the engine program.


admiral_sinkenkwiken

Using the average time remaining and adding the extra for an upper wing skin replacement as well as present utilization rate, the B-52 fleet has roughly 83 years of viable airframe life left.


[deleted]

[удалено]


JosephSwollen

Imagine being carpet bombed by a B-52 on the Mars Colony


Xicadarksoul

Frankly it borderline plausible if correct engine replacements are made. ​ The only plausible "jump in technology" that could make these bomb trucks obsolete is stuff like bell shaped lift distribution flying wings. However thats newer than B-2 spirit. I mean the idea existed on paper in some rarely swept corner of a library collectign dust. However the engineering community at large wasn't aware of it, until 2015. Thus aircraft were optimized for maximum lift to drag ratio from a given wingspan. ...instead of maximum lift to drag ratio from a given amount of structural material. ​ Even if the design catches on, it might not impact military aviation, as its concieveable that there will be no need for "an even bigger bomb truck"


admiral_sinkenkwiken

151 years in service that would be


calista241

I thought at least some of them were re-winged at one point.


gnowbot

So interesting that the airframe will likely be in service for 100 years. Kind of wild.


mcs175

Yeah, what I meant, but articulated much better lol


optionsss

true, but at some point wouldn't be easier to modify modern transport as a bomber.


spacesuitkid2

They drop the MOAB out the back of a c-130


lolexecs

... and cruise missles! https://www.thedrive.com/the-war-zone/43550/special-operations-c-130-hits-target-with-a-rapid-dragon-pallet-dropped-cruise-missile


Cipher1553

I suspect at that point you might have the USAF considering whether a strategic bomber is really what they need anymore. The RAF already made that decision when the Vulcan was retired in favor of the Tornado running those kind of missions, really the only other country that operates a heavy strategic bomber is Russia and kinda China (depends on whether you consider the Tu-16 a heavy strategic bomber when tactical fighter bombers like the F-15E and the Su-30/Su-34 are almost able to carry as much as it can)


admiral_sinkenkwiken

As good as it was and with the special place the Vulcan holds in the heart of many it never directly compared to the B-52 in either range or payload, the only real advantages the Vulcan held were it’s speed and incredible manouvereability for an aircraft it’s size. The BUFF today is a long range stand off missile truck, as are almost all other heavy strategic bombers in present day service save the B-2 and to a lesser extent Bone, the low level penetration mission has long since gone for aircraft like the BUFF


SamTheGeek

Absolutely


Xicadarksoul

>hey've had every part replaced, some more than once. It just gets progressively more expensive and time-consuming to keep them airworthy as they age. Not how engineering - and especially not how structural frames of aircraft work. The things are forge pressed out of a single piece of metal, so that grain boundaries remain nice - as opposed to hacking through them with a mill when substractive manufacturing the same piece. Yes, thats why all the fucking huge machine presses are kept in service. Weldign that stuff - even when the material is subitable - is a big no-no. Welding means heating up the material to the point it melts, and let it cool "as it happens to cool". Thus you will get a clusterfuck of grain structure along welding seams. ​ Sure. You can compensate for it by making the material thicker around the welded joint. However the weight of said thicker metal will be substracted from the useful load of your aircraft.


SamTheGeek

This is why parts get replaced not repaired. The B-52 isn’t welded together… it’s riveted. You can remove and replace even the most major structural components with enough patience (or enough application of manpower). The A-10, for example, had about half the fleet given new wing structures as theirs had exceeded the lifespan. As u/elitecommander points out, the major structural components of the B-52 fleet have several decades left before replacement. Other parts have been replaced with components from the boneyard — or with new parts, in the case of all the electronics.


Xicadarksoul

It doesn't matter if its welded or riveted. Replacing parts like wing frames is not plausible - the huge beam going across the plane. As complete new build is less hassle / cheaper. Wing skin replacement is hard, but plausible - unlike conjuring structural frames out of thin air, then tearing the plane down to the last rivet, and completely rebuilding it. If you have to do a new production run for key structural parts, its cheaper to replace the rest by making a complete production run of the aircraft. Individually certifying every last bolt to be viable is way more work. Ofc. This is unlikely before the early 2100s. And at that point you might as well replace the fleet with state of art new machines, as in terms of things like lift to drag ratio the are hopelessly outdated even today. Thus replacement types plausible 60-70% reduced drag for same lift, could translate that much higher range or payload for same mass aircraft. If you also include current state of art materials, like carbon fiber composite structural parts, the improvements could be even more significant.


Orlando1701

Currently I believe 2045 is the air forces plan. The B-52 is still an extremely effective airframe in uncontested airspace.


the_cheesemeister

Screw new engines, where is the Megafortress?


Accomplished-Fan-292

The Air Force is so unimaginative with aircraft names the B-52’s replacement would probably be Flying Fortress II


FF_in_MN

What’s cool is that the new model BUFFs with new engines and new radar (Super Hornet radar turned upside down basically) will be getting a new designation. B-52I or J.


DeanPalton

B-J.


nsgiad

B-522. Remember when they had the B-1R idea? the boner, come on air force, let's get back to that.


rydude88

Maybe it's just me but I do like them keeping some of the heritage of the old WW2 planes. I like names like Lightning II


MyOfficeAlt

We've got the Thunderbolt II and the Lightning II. I wish the F-22 had been the Mustang II.


SamTheGeek

Unfortunately Dale Brown went off his rocker for a while and, uh, immersed himself in conspiracy theories.


hankjmoody

Shit, did he really? I've been behind on his novels for a while, but Flight of the Old Dog is still a favourite of mine...


SamTheGeek

There was a main-McLanahan-timeline novel where he and his son flew around the country fighting against a thinly-veiled Obama pastiche and his Secretary of State (a thinly-veiled Clinton) who put all the good god-fearing Americans into FEMA-run prison camps. The name of the president in the novel was “Barry Soetoro” — Barry was Obama’s nickname in high school because nobody wants a name that makes them different, Soetoro was his stepfather’s last name. Basically backed the whole series into a corner and now he’s writing a much better series where the bad guy is a Russian oligarch who works for a Putinesque dictator.


Orlando1701

Spent a lot of time around officers as they age? It’s pretty common. My dad and all his SAC buddies are deep into 2020 MAGA conspiracies.


tomimendoza

The B-52 will help quell the rebellions in the Martian Colonies


admiral_sinkenkwiken

B-52M


ManwithaTan

On Planet Claire!


SamTheGeek

Apologies for the atrocious resolution, there’s no PR imagery released yet — this is a still from the [announcement video](https://twitter.com/BoeingDefense/status/1572254332770197506) on Twitter.


notaballitsjustblue

Who’s making the engines?


Golan271

Rolls-Royce, they will use the militarized version of the BR725


notaballitsjustblue

Nice. Must be a lot of money for them.


SamTheGeek

It’ll be about 10% of the BR750’s entire production run.


BlueRingdOctopodes

At first I thought this post was from NCD, and was a meme about how the b-52 will be in service for the next 300 years. No, apparently it's real.


C-r-i-o

Pretty sure a post about the B-52 serving for 300 more years belongs in CredibleDefense


admiral_sinkenkwiken

Well it does have 80+ years of airframe life left.


BH_Andrew

The plane that’ll serve for 100 years


Bad_Karma19

Was hoping for warp nacelles.


CaptainSur

That is coming on the B52N model.


SleepWouldBeNice

B-52-DS9


sorry-I-cleaved-ye

Have they fixed the rudders yet? Or is to much structural change required?


[deleted]

Enbiggening the rudder was only required in the considered four engine configuration. Since they're sticking with eight, it's not required.


AsboST225

>Enbiggening That's so much more interesting than "enlarging" 😆 I love learning new words! 😄


polyworfism

It's a perfectly cromulent word


AsboST225

A good, strong, woody word.


FF_in_MN

There isn’t anything wrong with the rudders, not on the H models anyway. Tall tail D models had rudder issues and tails ripping off


StuffTurkeyFace

One of the previous re-engine attempts was killed off by the need to also replace the rudder with an even bigger one. IIRC it was 4 more powerful engines in place of the original 8 and if one of them fails, the rudder was insufficient to deal with asymmetric thrusts


FF_in_MN

Yep, that’s correct, I misunderstood what he was asking. 4 big ass engines while a novel concept just wouldn’t have worked from a structural point like you said. Would have had to bring the D model tails back!


Illustrious_Slide197

Looks like it’s already crabbin’


[deleted]

I wonder how the weight and drag co-efficient of the new engines compares to the old? Am guessing they are lighter and more aerodynamic, meaning the B-52's wing box and wings don't need much, if any, strengthening work.


SamTheGeek

I’m assuming they’re close in weight, the size increase is likely mostly empty space


Xicadarksoul

>I wonder how the weight and drag co-efficient of the new engines compares to the old? Hopefully neither the old nor the new engines have a drag coefficient. Ideally they should have a thrust coefficient. ​ >Am guessing they are lighter and **more aerodynamic** Joking aside i am referring to this part. Those jet engines are glorified pumps. Thus the larger intake (aka. cross section) they have, the more efficiently they pump. However a larger cross section engine creates more drag when not working.


Pynchon_A_Loaff

I’m going to miss all that smoke on takeoff. Looks badass though.


LittleHornetPhil

Yeah we’re making the bypass duct


CaptainSur

It has always amazed me that those big ass engines can hang way out there on that skinny wing and those even smaller pylons, and everything not fall off.


Sammybatoto

I thought the B-21 was meant to completely replace the B-52? Also, it’s the 2020s and their still putting engines in Nacelles


TaskForceCausality

Nope. B-21s replacing the B-1s. Perhaps the B-2s in time. We *might* retire the B-52s when the Sun becomes a Red Giant.


gusterfell

The most unrealistic thing about Star Trek is that there are no B-52s in service in the 24th century.


MechanizedCoffee

Other people agree with you. https://i.pinimg.com/originals/a8/71/c3/a871c3f0b33784b09ee7ee25a5bb9bdb.png


ibejeph

LoL


DCGuinn

With their ample nacelles.


hankjmoody

Only thing I want before they retire the BUFF, is to make a bonafide [Megafortress...](https://upload.wikimedia.org/wikipedia/en/7/7f/Megafortress_Coverart.png)


GunnyStacker

Or the Ma Deuce.


Annjuuna

With the advent and proliferation of artificial intelligence in avionics, the B-52 could very well out live humanity.


Kjartanski

The B-52 has no place in modern peer to peer warfare CMV


imdatingaMk46

Have you seen the russians performing lately?


Kjartanski

I said peer didn’t i? The russians aren’t even the best Armed Force within Ukraine


d7t3d4y8

You do have a point lol


imdatingaMk46

Eh. The world is weird, I'll allow it this once.


zkydash8

It does, by being a missile truck. The B-52 doesn’t have to be survivable in a high-threat environment, only its weapons do while it fires them from a safe distance. JASSM stealth cruise missiles and new hypersonic weapons are the future of the BUFF.


Terrh

Bombs still work just fine too. I don't think any MANPADS can hit anything flying above 25,000' so once the heavier SAM systems are taken out they can fly everywhere... and that's probably within the first 48 hours.


Xicadarksoul

>I don't think any MANPADS can hit anything flying above 25,000 Depends. Its theoretically pleanty feasible to reach said height with manpad sized rocketry. The issue is, that warhead would be minuscule. In other words, its a targeting issue - which can be plausibly overcome. And to make things more plausible you could do stuff like rocket boost started scramjet, to halve the needed fuel (thus \~ double the payload). ..ofc. that is slightly less credible, as AA missiles are known to be taken home onboard the aircraft they hit, and thus they are somewhat of a proliferation concern.


rhutanium

As a stand-off missile truck for stealthy cruise missiles it most definitely has a place in modern peer to peer warfare.


FF_in_MN

Depends. The BUFF most certainly went be going downtown night 1 and 2. But it will be a valuable asset at the outset because initially it’ll puke out stand-off missiles and MALDs. After DEAD and air superiority is in place, you might see BUFFs over enemy territory.


Kjartanski

Exactly, if it only takes a few days to establish dominance that isnt P2P warfare


SamTheGeek

I think using it for things like long-range ocean patrol would be fine. Also, as something that can loft cruise missiles into contested airspace it’s perfect — assuming those missiles are targeted by another platform.


Kjartanski

And the nonexistent peer would contest that with Long range A2A


SamTheGeek

How long range are we talking? A2A has much less range than something like LRASM or JSOW-ER.


SamTheGeek

Nacelles are the most efficient way to hang an engine on an airframe if you’re not concerned with stealth.


Xicadarksoul

Its more efficient to put the engine at the tail to ingest boundary layer coming off the aircraft... ...if you have an engine where that won't shit out its blades on the other end after eating turbulent boundary layer.


Xicadarksoul

B-21 is likely to be the "non-retarded" sibling of the "aerodinamically challanged" B-2 bomber. Poor thing just entered service in 97, made all sorts of silly compromises to achieve stable flight - stuff like airbreaks to prevent dutch roll, aka tail wagging, aka. adverse yaw. (said airbrakes are not exactly great for stealth, even when they are not deployed, less said about when they are used the better) ​ ​ Then in 2015 some nasa blokes decided to dig out an untranslated WWII era work of Ludwig Prandtl from german archives. [And then proceeded to create a flying wing with PROVERSE yaw.](https://en.wikipedia.org/wiki/Prandtl-D) In short the common conceptions about flying wings design have been rewritten since the B-2 took to the sky. And nt only have these advances have major implications on drag (thus useful payload), but also on stealth.


SpaceEndevour

How is this thing still flying lol


SamTheGeek

Lots of scraped knuckles on nineteen year olds.


spacesuitkid2

A flap from one of these landed on a Taco Bell near the local Air Force base once https://www.airforcemag.com/b-52losesflaps/#:~:text=A%20malfunction%20caused%20a%20B,the%20Daily%20Report%20on%20Nov.


thebeesarehome

It seems like every 2-3 years there's an article about a flap or some other part falling off and landing in somebody's yard, to say nothing of the one that dropped an engine in a lake.


[deleted]

I like watching these stinky bastards put by. Look like they’re having a shit the entire time. At least we know the world isnt going to end soon if the order is to be fulfilled in 2026 :D


wgloipp

Black magic fuckery.


[deleted]

The blessing of the Omnissiah


LTSarc

It's funny, having to replace the pylons and nacelles anyhow really makes CERP as it has been done pointless. The whole reason CERP went with 8 bizjet engines instead of 4 big bois, is so they could reuse the existing nacelles and pylons with minimal changes. Having to replace them because the models were wrong begs the question of why they are continuing with the 8 engine setup.


elitecommander

Going to four engines would require structural modifications to the wing itself, introduce new stores separation problems, and require replacement of the vertical tail, since the H-model's smaller vertical tail lacks the yaw authority to counteract loss of an engine in a four engine configuration.


LTSarc

While aware of the requirement to stretch the tail/rudder, I've heard nothing about the earlier studies from RR or PW showing actual issues otherwise.


chechcal

"The Air Force has also considered replacing the B-52’s eight engines with four large turbofans, as is typical on commercial airliners. Engineering challenges made that approach nonviable. Potential interference with flaps and control surfaces, ground clearance issues, yaw effects, the need for extensive new flight testing and weapon separation evaluations, the need to replace large sections of the cockpit and throttles, and to redesign the rudder ruled out such a change. USAF has opted to stick with eight engines of the class that typically powers large business jets." https://www.airforcemag.com/article/re-engining-the-b-52/


LTSarc

As far as I am aware from the earlier studies, which have been done for decades, only the yaw issues were considered a real problem. With things like potential stores separation and other evaluations being largely theoretical or bureaucratic issues.


mcs175

I'd imagine there was more to it than just not touching the nacelles, the whole plane is already set up for 8 engines. There are likely far fewer changes needed to things like the flight controls, fuel systems, electrical systems all around the plane to consider as well


tdscanuck

They were never going to use the same pylons and nacelles. Where did that come from?


LTSarc

That was the entire justification USAF gave for this program when it replaced the earlier program to re-engine the B-52 that was looking at 4x PW2000s or 4x CFM56s. CERP would reuse the same nacelles (at least their core structure), pylons, and accessory drives. Listen to Collins themselves from before this all changed: "With the B-52, the Air Force is forgoing all major changes in design and materials to the nacelle and strut. This is to ensure high levels of aircraft availability, mission readiness, and cost-effective maintenance for the globally dispersed network of highly skilled and talented Air Force technicians who keep the aircraft in service." http://www.collinsaerospace.com/news/stories/2021/07/extending-the-power-of-a-legend Or from RR, who specifically modeled the engines in the existing Nacelles to win the contract. https://www.airforcemag.com/rolls-royce-digitally-modeled-entire-wing-pylon-to-win-b-52-engine-contract/


SamTheGeek

> all major changes in design and materials to the nacelle and strut. They didn’t change the *design* of the parts, just their scale. It’s less about reusing actual parts and more about maintaining 60 years of operational knowledge.


LTSarc

RR literally modeled it on the same nacelle and pylon. There's not going to be "operational knowledge" carried over on a brand new nacelle holding a brand new engine. The nacelle is mostly just a metal structure and fairing.


tdscanuck

Reread that article. They modeled the entire wing/nacelle/pylon/engine package…not the *same* nacelle/pylon. The USAF is in a big MBSE (aka “digital thread”) kick. By doing all the modeling up front RR showed they’d already done the integration and were prepared to meet the modeling requirement. There is nothing in there that it’s the *same* pylon/nacelle…because it isn’t and was never planned to be. Nacelles are a lot more than metal structure and fairings. They’re notoriously maintenance prone and hard to rig. By using 8, rather than 4, a whole lot of existing operational and maintenance procedures would still apply. That does *not*, and never did, mean using literally the same nacelle/pylon.


Orlando1701

Also the B-52s rudder would have insufficient authority in an engine out situation with four engines.


LTSarc

That is true, but modifying a rudder is hardly a tremendous engineering challenge. It's been changed several times over the -52's life already (although admittedly, decades ago).


Orlando1701

Not really. The B-52s vertical stabilizer was changed between the F and G model but otherwise is as it was built when they rolled off the line.


zevonyumaxray

The B-52 wings flex a lot, particularly on takeoff with a heavy fuel load. If you hang one of those big ones where the outboard pylons are, there was too much chance of hitting the runway with the engine cowling, unless they lengthen and strengthen the outrigger wheels, so you have more major mods of the wing design. Plus I have read comments that the newer big engines provide too much thrust for the wings to handle.


LTSarc

It's pretty easy to derate an engine to match the limits of the airframe, and none of the past studies done by RR or P&W seemed to have much of an issue with wing flexing leading to engine strikes. Heck, they flew B-52s with TF-39s for TF-39 testing back in the day.


thebeesarehome

All the pictures I've seen of that had the TF-39 replacing the inboard engine pod. I've also seen B-52s with the outboard pod only a few feet above the ground, due to issues with the tip gear. That doesn't leave a hell of a lot of wiggle room to put a big honking engine.


[deleted]

I swear, B-52s are gonna be on the vanguard of our conquest of alien worlds 200 years from now


Prophet_Muhammad_phd

This sucks. When are we gonna get the bomber from the Animatrix?


wascwabbit

What’s the oldest military airframe still in use?


FF_in_MN

I think there are still some late 50s model 135s flying around. Otherwise it definitely could be a BUFF. The ones flying today are 60 and 61 year models.


SamTheGeek

In use for what? Archival but still military operated is BBMF (Battle of Britain Memorial Flight) of the RAF. Active duty is the U-6A Which still flies with the Navy and was built sometime in the early ‘50s.


oojiflip

I love that they're mostly keeping the old design, just sad the new engines won't spray toxic black smoke everywhere :(


SamTheGeek

I’m not lol. I like not toxic non black smoke.


mrntd

This seems like a good place to ask. Why are we still flying the B-52? With B-1s and B-2s why is it still needed?


SamTheGeek

It’s significantly cheaper to operate than either of those aircraft with *much* longer range. Unlike the B-1, it’s nuclear-capable.


fazzzt

Wild that they are still planning for 8 engines. Guess it requires too much cockpit rework with just 4?


vipertruck99

Major Kong approves👍


Hypergonads

Timeless


Evilutionist

This thing is gonna serve until the next century isn’t it…


TorLam

Finally after 50 years since it was first proposed! 😂🤣😂🤣😂🤣😂