Boeing B-52J / B-52 Re-Engining

I do wonder if there are AI ?presences? here sometimes, spooky. Perhaps Muddy and Scummy can investigate
 
TomS said:
Boldface refers to emergency procedures that are written in bold in emergency checklists and which flight crew are expected to have memorized and be able to perform without looking at the checklist. Weekly knowledge means it's quizzed regularly, so it should be absolutely engrained in the crew.
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Thanks @TomS ! Beat me to it. During my time as a military aviator, I executed the Boldface four times; two fires, one engine gearbox chip detector (loss of the engine), and one loss of cabin pressurization (could throw in a departure from controlled flight, but that was the pilot's Boldface). It's important because it goes to the fight or flight psychology. When you thoroughly ingrain a specific response to a specific emergency, then reinforce it through practice of said emergency, weekly recitation of the response, when it occurs for real the lifesaving response is preloaded.

The first three emergencies I described my pilot, and I literally said the Boldface together as we executed it, and I opened the EP's. Then read the EP's to the pilot challenge/response. I'm alive today because of it and a big fan.
 
Interesting bits on the crew side of things:

It pushes out our strike capabilities,” said 1st Lt. Rebecca Moore, a B-52 electronic warfare officer (EWO). “And the efficiency minimizes how much aerial refueling you have to do.”

In a massive aircraft like the B-52, aerial refueling from an older aircraft like the KC-135 Stratotanker can be tough to hold in place and stay steady—“fatigue-inducing,” B-52 pilot Capt. Michael Brady said. A different Air Force modernization effort, the KC-46 Pegasus, will also make a difference for B-52 crews.

“The bumpiness of the KC-135 versus the KC-46 is… my day is made, when the aerial refueling is with the 46,” said Moore, who sits in the back on the same floor as the pilots but facing backward, adding that her experience as an EWO can differ from the feelings in the cockpit.

Brady described the KC-135 as the bomber’s “best pal,” but also said the KC-46 “is forgiving, not to inspire complacency, but it’s definitely a confidence booster. It’s an incredibly capable plane.”
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www.airandspaceforces.com

At Barksdale, B-52 Crews Are in High Demand—And Looking Forward to Upgrades

The 2nd Bomb Wing at Barksdale Air Force Base is in high demand around the globe as they wait for their B-52s to be upgraded soon.
www.airandspaceforces.com www.airandspaceforces.com
 
FighterJock said:
2060? I had thought that it was 2052 for the B-52. That would make it THE worlds oldest bomber by far, even older than the Tu-95 which is going to go to the 2040s by comparison.
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True but it's main job is to launch long-range cruise missiles from thousands of km away, so it's age, appearance and RCS is moot.
 
FighterJock said:
2060? I had thought that it was 2052 for the B-52. That would make it THE worlds oldest bomber by far, even older than the Tu-95 which is going to go to the 2040s by comparison.
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The youngest B-52H was built/ entered service in 1962.

For the oldest Bear-H the equivalent year is 1983 (and the maritime Bear-Fs at their oldest date from the mid 70’s). The Bears airframes still in service are nowhere near as old as their B-52 equivalents.

The originals of both first flew in 1952 (the B-52 more than 6 months earlier) and they entered service in 1955 and 1956 respectively. No matter how you slice it the B-52 is the older design, represents much older/ longer served airframes and are scheduled to have much longer service lives. The Bear-Hs in service would need to serve 20 plus years longer than the currently in service B-52s to “catch up”, if as planned they go out of service first then they won’t even be close.
 
Might have been shared before, but a good read nonetheless .....

www.airpowerstrategy.com

Old Dog, New Engines: The Truth about a B-52 Re-Engine - angle of attack

It seems that the USAF cannot get through a year without being inundated with calls to replace the engines on the B-52. Recent calls from Air Force Global Strike Command,[1] Boeing, General Electric[2] and Pratt & Whitney[3] have renewed the vigor of the program despite the general lack of...
www.airpowerstrategy.com www.airpowerstrategy.com
 
I wonder if one or two of the B-52Hs will be put aside for preservation in a museum?
 
zjz said:
Depending on how serious the fire damage is
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The damage to the nacelle and pylon wouldn't be of concern since they're supposed to be replaced with new nacelles and pylons in the re-engining however the damage to the wing is of concern. I don't know how much it would cost but given how extensive this rebuild/modernisation is going to be they may as well replace the wings too with new-build wings.
 
All B-52G that are not in museums should have been chopped or scrapped due to Arms Limitations treaties? So, there are no -G airframes left for possible conversion to -J?
 
zjz said:
All B-52G that are not in museums should have been chopped or scrapped due to Arms Limitations treaties? So, there are no -G airframes left for possible conversion to -J?
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They were cut up into large chunks using linear shaped-charges but I don't know if those chunks have been recycled. Assuming they haven't you'd have to send them back to Boeing to be completely dismantled, inspected and damaged parts thrown away before reassembly which of course would involve building new jigs and tooling.
 
Wait a bit further. We will see rebuilt fuselage sections. Even upgraded.
That's the logical long term end-results of a full digitalization effort such as is running now.
 
TomcatViP said:
That's the logical long term end-results of a full digitalization effort such as is running now.
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I assume that by now Boeing will have digitised all of the B-52H's engineering drawings so that they're now also existing as CATIA CAD files?
 
zjz said:
All B-52G that are not in museums should have been chopped or scrapped due to Arms Limitations treaties? So, there are no -G airframes left for possible conversion to -J?
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Yes. Plus there were differences between the versions and of course any active H would have a vast slew of updates no G would have. The 10-11 H models at AMARG are the only possible attrition replacements. I believe two were restored in the last decade or two.
 
NMaude said:
They were cut up into large chunks using linear shaped-charges but I don't know if those chunks have been recycled. Assuming they haven't you'd have to send them back to Boeing to be completely dismantled, inspected and damaged parts thrown away before reassembly which of course would involve building new jigs and tooling.
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The chunks are still visible on satellite for treaty verification reasons.
 
TomcatViP said:
Wait a bit further. We will see rebuilt fuselage sections. Even upgraded.
That's the logical long term end-results of a full digitalization effort such as is running now.
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I have often wondered just what is left on the present airframes that was installed when they were originally built. Having seen the PDM line at Tinker for KC-135s and nearby was the B-52 line (which were unable to visit), they still have something of their original structure.

We did catch a B-52H coming back from its first test flight after PDM.

Enjoy the Day! Mark
 

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NMaude said:
They were cut up into large chunks using linear shaped-charges but I don't know if those chunks have been recycled. Assuming they haven't you'd have to send them back to Boeing to be completely dismantled, inspected and damaged parts thrown away before reassembly which of course would involve building new jigs and tooling.
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Linear shaped-charge? Never heard that before.

 
sferrin said:
Linear shaped-charge? Never heard that before.
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psemc.com

Linear Shaped Charge | PacSci EMC

Linear shaped charge consists of a continuous explosive core enclosed in a seamless metal sheath, formed into an appropriate shape to sever the target.
psemc.com psemc.com

Product Description​


Linear Shaped Charge (LSC) is used to cut various types of metal in separation systems, from launch vehicles to missiles, in space, military and underwater applications. Linear Shaped Charge is a continuous explosive core enclosed in a seamless metal sheath, formed into an appropriate shape to sever the target.


Normally the shapes are either a chevron or inverted “V” shape or similar to the profile of a ‘house’. The type of metal determines the flexibility of the charge. Chevrons for Flexible Linear Shaped Charge (FLSC) are easier to form intricate patterns for a Canopy Fracturing System (CFS). The house shape is for more ridged designs especially for Flight Termination or Separation Systems by LSC assemblies. These shapes provide what is known as the “Munroe” effect when the linear shaped charge is detonated. The Munroe Effect is the reinforcement of shock waves in a hollow charge, concentrating the effect of the explosion along the axis of the charge. In this case, the Munroe Effect is enhanced by carefully controlling the charge dimensions and configuration for each application.


The metal sheath liner is most commonly formed using copper, aluminum, lead or silver. Generally, most large core loads utilize copper however for structural integrity Aluminum is recommended. When it comes to flexibility and with small core loads a lead liner is recommended. Silver is primarily used with thermally resistant explosive core loads. As for the powders most commonly used, there is RDX, HMX, PETN and HNS.


Upon detonation, the continuous metal sheath liner and explosive produce a uniform linear cutting action. PacSci EMC will determine the best combination of explosive core and metal sheath to sever the target specified. Factors such as the type of target material, its thickness, operational temperature exposure, standoff distance, vibration, shock, etc. assist in determining the proper LSC / FLSC.
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I think sferrin was indicating that the B-52G force was not in fact disassembled with explosives but instead used a crane mounted mechanical device. I suspect he's familiar with linear shaped charges.
 

The AMARC Experience - Strategic Arms Reduction Treaty

AMARC - Aircraft Maintenance And Regeneration Center. 309th Aerospace Maintenance and Regeneration Group. Comprehensive source of information on the important j
www.amarcexperience.com www.amarcexperience.com
Originally AMARC used a 13,500lb guillitine blade to slice through each B-52. The blade was hoisted to a height of 80 feet using a crane and then unceremoniously dropped on each predefined cut point. This approach was very effective in slicing through the airframe. The resulting sections of the aircraft were arranged for easy identification to satellite (the main verification method used by the Russian and Ukranian observers) and after 90 days the wreckage was sold to local scrap metal companies for disposal. Some 150,000 pounds of aluminium and other metals were available for recycling from each aircraft.


AMARC have progressed from this 'brute force' elimination method to a more 'surgical' method using power saws. The reason for this is that the B-52G's have many components that can be used to support the operational B-52H's, the guillitine method made it very difficult to preserve the interior of the aircraft after the operation. By using power saws, precision cuts are made and afterwards spraylat (the same material used to preserve the other aircraft stored at AMARC) is used to seal any holes exposing interior areas of the aircraft. Spare parts can then be retrieved at a later stage without fear of degradation due to exposure to sun, rain and dirt.
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guillitine = guillotine
To be honest, I haven't found anything about linear shaped-charges being used for chopping up B-52s, but the guillotine-method was abandoned a while ago.
 
B-52 makes a interesting case study for "Ship of Theseus" .....


Ship of Theseus - Wikipedia

en.wikipedia.org en.wikipedia.org

The Ship of Theseus is a thought experiment about whether an object is the same object after having had all of its original components replaced.

In Greek mythology, Theseus, mythical king and founder of the city Athens, rescued the children of Athens from King Minos after slaying the minotaur and then escaped onto a ship going to Delos. Each year, the Athenians would commemorate this by taking the ship on a pilgrimage to Delos to honour Apollo. A question was raised by ancient philosophers: After several hundreds of years of maintenance, if each individual piece of the Ship of Theseus was replaced, one after the other, was it still the same ship?

In contemporary philosophy, this thought experiment has applications to the philosophical study of identity over time, and has inspired a variety of proposed solutions and concepts in contemporary philosophy of mind concerned with the persistence of personal identity.
 
zjz said:
B-52 makes a interesting case study for "Ship of Theseus" .....


Ship of Theseus - Wikipedia

en.wikipedia.org en.wikipedia.org

The Ship of Theseus is a thought experiment about whether an object is the same object after having had all of its original components replaced.

In Greek mythology, Theseus, mythical king and founder of the city Athens, rescued the children of Athens from King Minos after slaying the minotaur and then escaped onto a ship going to Delos. Each year, the Athenians would commemorate this by taking the ship on a pilgrimage to Delos to honour Apollo. A question was raised by ancient philosophers: After several hundreds of years of maintenance, if each individual piece of the Ship of Theseus was replaced, one after the other, was it still the same ship?

In contemporary philosophy, this thought experiment has applications to the philosophical study of identity over time, and has inspired a variety of proposed solutions and concepts in contemporary philosophy of mind concerned with the persistence of personal identity.
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It is a fair question, but from an aviation point of view it avoids a key concern: how much does it cost to design a new ship, at any point in the timeline? Given that B-52s still use the exact same engine models, I would argue that is a bigger consideration than counting the original rivets in the airframe. That consideration is why it took so long to actually re-engine them, especially considering the number of available engines.
 
Yes since the B-52's have had a wing strut replacement due to early fatigue, an airframe reconditioning which replaced a lot of the metal, two replacement sets of cockpit avionics, a skin replacement and numerous engines early on combined with the recent engine replacement, it really is a case of Triggers Broom.
 
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WatcherZero said:
Yes since the B-52's have had an airframe reconditioning, two replacement sets of avionics, a skin replacement and numerous engines early on combined with the recent engine replacement on it really is a case of Triggers Broom.
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It is, if a broom had to move at 500 mph at 30,000 feet. I get what you are saying, but what I'm saying is I think more of a 60's hot rod car with a non matching engine number and replacement parts. Sure, it is not the same car or the most efficient thing to drive, and anything modern could do circles around it. But if you drop another Chevy 350 into it, it should operate about the same. But if you want to change center of gravity and engine output, well then perhaps you should get a new car rather redesign it. And there's a price tag associated with that.
 
Josh_TN said:
It is a fair question, but from an aviation point of view it avoids a key concern: how much does it cost to design a new ship, at any point in the timeline? Given that B-52s still use the exact same engine models, I would argue that is a bigger consideration than counting the original rivets in the airframe. That consideration is why it took so long to actually re-engine them, especially considering the number of available engines.
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I thought the convoluted process for finally gettng a new engine was more funding/resolve driven than anything else. Yes, some of the earlier proposals were dropped as the engine out situation could not be met with replacing 8 with 4 and ground clearance considerations as well. I probably missed something over the years....

Enjoy the Day! Mark
 
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Josh_TN said:
It is, if a broom had to move at 500 mph at 30,000 feet. I get what you are saying, but what I'm saying is I think more of a 60's hot rod car with a non matching engine number and replacement parts. Sure, it is not the same car or the most efficient thing to drive, and anything modern could do circles around it. But if you drop another Chevy 350 into it, it should operate about the same. But if you want to change center of gravity and engine output, well then perhaps you should get a new car rather redesign it. And there's a price tag associated with that.
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What I am saying is they are probably only 15/20% original material left. Its like rebuilding a classic car from just a chassis so it keeps the original license plate.
 
WatcherZero said:
What I am saying is they are probably only 15/20% original material left. Its like rebuilding a classic car from just a chassis so it keeps the original license plate.
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Perhaps, but in this case it is less about trading value or bragging rights and more about keeping the existing aircraft inside its specs, when making major alterations would be far more expensive and dangerous than the classic car analogy.
 
WatcherZero said:
Yes since the B-52's have had a wing strut replacement due to early fatigue, an airframe reconditioning which replaced a lot of the metal, two replacement sets of cockpit avionics, a skin replacement and numerous engines early on combined with the recent engine replacement, it really is a case of Triggers Broom.
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Not really. No B52s were converted from one suffix letter to another, all were built as B-52A-G (J57s) or B52H (TF33s).

B52Ds were the last of the "big tail" versions, succeeding aircraft got a smaller vertical tail to more happily fly at low altitudes, and the -Ds were retired after Vietnam.

Re-engining a B52 with 4x high bypass turbofans would have required a much larger tail than on the -Gs or -Hs, to give enough rudder area in case of losing an outboard engine on takeoff. And that got into trouble with engine sizes, there were very few engines in that particular size class (both diameter and thrust) in existence before the late 1990s.
 
1 B-52A was converted to a NB-52A with an additional pylon and wing flap cutout section
7 B-52B's were converted to C's under project Sunflower
1 B-52B was converted to a NB-52B for NASA with an additional pylon and wing flap cutout section
1 B-52E was converted to a NB-52E with added canards and modifications to reduce vibrations and vulnerability to wing gusts for low level flying
1 B-52E was leased to General Electric as the JB-52E and had both TF39 and CF6 engines fitted


The first two prototypes were fitted with YJ57-P-3 engines
The A's were witted with J57-P-1W, The B's and D's had the J57-P-29W, J57-P-29WA or a J57-P-19W all with the same non-water injected output of 10,500 lbf
The F and G's had the J57-P-43WB
The H had the TF33-P-3
And now the H's will be re-designated J's and be refitted with a Rolls-Royce F130

So thats 10 different engines the B-52 has had in its lifetime.
 
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