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New BUFF Engines (Finally)


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After working the past 40 years on TF-33's or JT3D's anything will be a improvement.  I had one stretch in Saudi where I changed 7 TF-33's in two weeks on the same tail number(E-3C). Always a oil pressure related problem. The last 7 years on KC-135's I've changed 4 engines on a fleet about 400 airplanes and some those jets still have the same engines on the wing when they were hung when upgraded from A to R model, that is what they are hoping for.


IIRC they pulled a F108 off of 0123 early to get some data on engine fatigue in 2011. The motor was initially installed in 1984. I’ve flown tails that have never swapped R model motors since their initial mod.


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10 hours ago, fire4effect said:

Weeellll the hydromechanical MEC of the -2s IS inherently nuclear hardened. 😁

I haven't changed CFM56's frequently, always dropped them on 737's classics and NG's for lease returns but I have changed a crap load of MEC's, probably the engines weakest feature. Always wondered why the USAF never got thrust reversers for the 135 then I worked on a E-6 and I figured out why. The 135 hydraulic system would have to be seriously upgraded to handle the volume and pressure of fluid to actuate them. So just replacing the steel brakes with carbon fiber is cheaper.  

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Update

So, basically were looking at

1 Year for GE and Pratt to appeal the decision. 

2 Years to build the first 8 motors.

2 Years to modify the airframe and avionics.

2 years worth of flight testing at Edwards.

Air Force asks Congress for funding for the program.

Congress cancels engine program, Proposes buying additional B-21s.

Edited by MC5Wes
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2 hours ago, MC5Wes said:

Update

So, basically were looking at

1 Year for GE and Pratt to appeal the decision. 

2 Years to build the first 8 motors.

2 Years to modify the airframe and avionics.

2 years worth of flight testing at Edwards.

Air Force asks Congress for funding for the program.

Congress cancels engine program, Proposes buying additional B-21s.

My laughing reaction was a nervous laugh 🙂

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2 hours ago, MC5Wes said:

Update

So, basically were looking at

1 Year for GE and Pratt to appeal the decision. 

2 Years to build the first 8 motors.

2 Years to modify the airframe and avionics.

2 years worth of flight testing at Edwards.

Air Force asks Congress for funding for the program.

Congress cancels engine program, Proposes buying additional B-21s.

61129005.jpg

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12 hours ago, Prosuper said:

I haven't changed CFM56's frequently, always dropped them on 737's classics and NG's for lease returns but I have changed a crap load of MEC's, probably the engines weakest feature. Always wondered why the USAF never got thrust reversers for the 135 then I worked on a E-6 and I figured out why. The 135 hydraulic system would have to be seriously upgraded to handle the volume and pressure of fluid to actuate them. So just replacing the steel brakes with carbon fiber is cheaper.  

Let me guess. The MECs you were pulling were overwhelmingly ones overhauled at AF Depot while the most reliable ones were overhauled by the OEM. 🤨

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9 hours ago, fire4effect said:

Let me guess. The MECs you were pulling were overwhelmingly ones overhauled at AF Depot while the most reliable ones were overhauled by the OEM. 🤨

I am shocked shocked that you would disparage AFMC 2 level mx like that, even what you said is 100% true there are differences between a FAA certified and USAF repair station. 

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Is this engine a new design? It seems like you could cut a ton of time off of that. 

Not at all. It’s off the shelf; already on the BACN and C-37, as well as civilian G500 and Global Express.
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4 hours ago, SurelySerious said:


Not at all. It’s off the shelf; already on the BACN and C-37, as well as civilian G500 and Global Express.

Will the new engines give the BUFF a substantial increase in thrust/payload capability or is it more reliable/ease of MX/sustained supply chain?  Understood if you can't get into specifics on this forum.  I'm currently going through MC-J transition and the upgrade to newer engine technology feels like going from a rotary to cell phone.

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35 minutes ago, DirkDiggler said:

Will the new engines give the BUFF a substantial increase in thrust/payload capability or is it more reliable/ease of MX/sustained supply chain?  Understood if you can't get into specifics on this forum.  I'm currently going through MC-J transition and the upgrade to newer engine technology feels like going from a rotary to cell phone.

What I’ve read says same thrust class, better fuel efficiency and less maintenance intensive. I think they wanted to keep it to the same thrust to not have to completely redo the TOLD, as well as not having to do too much work to strengthen the engine pylons. 

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What I’ve read says same thrust class, better fuel efficiency and less maintenance intensive. I think they wanted to keep it to the same thrust to not have to completely redo the TOLD, as well as not having to do too much work to strengthen the engine pylons. 

I think a lot of people fail to look at the idea of a reduction in maintenance tasks and how much that multiplies when you are talking about a plane with 8 god damned motors to do oil checks and service inspections on much less fix.

That translates to either maintaining troop counts to do other tasks, or reducing the Manning requirement without negatively impacting OR rates.


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14 hours ago, SurelySerious said:


Not at all. It’s off the shelf; already on the BACN and C-37, as well as civilian G500 and Global Express.

I’d seriously hope with an existing time that it wouldn’t take multiple years to field.

And is TOLD in a BUFF that major of an event? Not like you’re doing austere ops out of dirt strips where you’re gnats assing it. 

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I’d seriously hope with an existing time that it wouldn’t take multiple years to field.
And is TOLD in a BUFF that major of an event? Not like you’re doing austere ops out of dirt strips where you’re gnats assing it. 

The BUFF isn’t ever thrust limited; it doesn’t need more. It’s stopping limited (old steel brakes suck), directional control limited, and mx/fuel limited.

Same thrust engines let you minimize change to controllability and structural problems, not exacerbate directional control problems, and keep the engines on the wing longer while increasing un-refueled range.

Edit: “isn’t ever thrust limited” = incredibly rarely, of course
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19 hours ago, 08Dawg said:

What I’ve read says same thrust class, better fuel efficiency and less maintenance intensive. I think they wanted to keep it to the same thrust to not have to completely redo the TOLD, as well as not having to do too much work to strengthen the engine pylons. 

I sympathize with the TOLD; about 10 years ago our planes got carbon brakes, best mod the Bobs had put on the airplane in a long time.  Trouble was, they didn't want to pay for the testing to redo the TOLD so all our numbers were still based on the old steel brakes.  I could kinda understand that since at the time I was in legacy MCs and we had an upcoming (though moved several times) retirement date.  I assumed that the newer MC-J would have revised TOLD since the aircraft is gonna be around for 30+ years.  Wrong.  TOLD is still based on the old brakes even though all the aircraft have been modd'd with the new ones.  So our portions of our TOLD is "more better" but you don't know how much better and still have to use the old numbers.

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1 minute ago, DirkDiggler said:

I sympathize with the TOLD; about 10 years ago our planes got carbon brakes, best mod the Bobs had put on the airplane in a long time.  Trouble was, they didn't want to pay for the testing to redo the TOLD so all our numbers were still based on the old steel brakes.  I could kinda understand that since at the time I was in legacy MCs and we had an upcoming (though moved several times) retirement date.  I assumed that the newer MC-J would have revised TOLD since the aircraft is gonna be around for 30+ years.  Wrong.  TOLD is still based on the old brakes even though all the aircraft have been modd'd with the new ones.  So our portions of our TOLD is "more better" but you don't know how much better and still have to use the old numbers.

Lockheed has the data.. the AF won’t pay for it. Same for data on AMAX climb performance and a host of other things we all get to just guess on.

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1 hour ago, herkbier said:

Lockheed has the data.. the AF won’t pay for it. Same for data on AMAX climb performance and a host of other things we all get to just guess on.

Thanks for sharing, did not know that.  Wonder how much Lockmart wants for the data?  I get having it isn't a "must" but sure would be nice to have.  Apologies for the minor thread derail.

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2 hours ago, DirkDiggler said:

Thanks for sharing, did not know that.  Wonder how much Lockmart wants for the data?  I get having it isn't a "must" but sure would be nice to have.  Apologies for the minor thread derail.

I think I read in another thread you are going through MC-J transition training; when you get to your unit, look into getting the Lockheed test pilots to come out to your Sq and give a presentation and Q&A. 
 

I’ve been to two or three of their roadshows and they were well worth the time. They did some TOLD presentations, cleared up some myths about the J and answered a ton of questions for us. I don’t have a POC, but I’d bet OGV does. 

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39 minutes ago, herkbier said:

I think I read in another thread you are going through MC-J transition training; when you get to your unit, look into getting the Lockheed test pilots to come out to your Sq and give a presentation and Q&A. 
 

I’ve been to two or three of their roadshows and they were well worth the time. They did some TOLD presentations, cleared up some myths about the J and answered a ton of questions for us. I don’t have a POC, but I’d bet OGV does. 

I'll definitely keep this in mind, thanks for the insights.

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To the best of my memory(which ain't too good nowadays) unlike the OG Herks Lockheed paid for the development of the Jay model. That's why we have to pay for all that info.

Lockheed Aero in Marietta, pronounced Mayrettah in southern, does the roadshows. Wealth of information. No idea how much they charge for it.

Dirk, don't know where you're at but if they have one at CVS I'd love to attend.

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3 hours ago, arg said:

To the best of my memory(which ain't too good nowadays) unlike the OG Herks Lockheed paid for the development of the Jay model. That's why we have to pay for all that info.

Lockheed Aero in Marietta, pronounced Mayrettah in southern, does the roadshows. Wealth of information. No idea how much they charge for it.

Dirk, don't know where you're at but if they have one at CVS I'd love to attend.

I’ll be PCSing out your way beginning of next year, if I’m able to coordinate said visit I’ll definitely reach out.

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On 10/2/2021 at 10:48 AM, DirkDiggler said:

I sympathize with the TOLD; about 10 years ago our planes got carbon brakes, best mod the Bobs had put on the airplane in a long time.  Trouble was, they didn't want to pay for the testing to redo the TOLD so all our numbers were still based on the old steel brakes.  I could kinda understand that since at the time I was in legacy MCs and we had an upcoming (though moved several times) retirement date.  I assumed that the newer MC-J would have revised TOLD since the aircraft is gonna be around for 30+ years.  Wrong.  TOLD is still based on the old brakes even though all the aircraft have been modd'd with the new ones.  So our portions of our TOLD is "more better" but you don't know how much better and still have to use the old numbers.

Same thing happened with the KC-135, but we finally did get carbon brake data.  I think it took at least 5-6 years to get though.  Hellava difference.  For the most part, I think the Air Force cared more about maintenance costs than aircraft performance.

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I can provide some insight on the J carbon brake and AMAX data as I have been involved with both. I can also provide POCs at Lockheed for the test pilot roadshow if you want to PM me.

RE: Carbon brakes. USAF completed their own testing without LM involvement, and their goals did not include assessing stopping performance differences. They were only looking at form/fit/function and mx perspective. Testing was on an E model and USAF cleared the carbon brake mod on all models. On the J, they discovered that cold brakes couldn't hold against TO power. Oops. I think a workaround has been created for that. A few other J operators completed their own testing, so I'm not sure if LM has sufficient data to update all TOLD. The primary benefit is extra brake energy capacity which would eliminate many of the brake energy limitations if implemented in in the performance manual.

RE: AMAX climbout data. LM does have this data. I have been pushing to add it to our C-130J preTOLD app as a low-cost option and major benefit for operators. Unfortunately can't get into the details of those discussions, but I'm still pushing. LM owns all J aircraft data since it was originally a commercial development effort.

RE: BUFF re-engining. Not involved with this, but my experience with engine upgrades (C-130J, C-5M, NP2000 props) tells me that more thrust should only be considered if current performance is thrust-limited over a large part of the envelope. More thrust drives a lot of other major changes - pylon structure, directional controls, stability margins, VMCs, etc. - and blows up the project scope. Primary benefits are fuel efficiency, digital controls, mx reduction, better access to parts/spares, etc.

Edited by HerkPerfMan
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On 10/1/2021 at 10:43 PM, Danger41 said:

I’d seriously hope with an existing time that it wouldn’t take multiple years to field.

And is TOLD in a BUFF that major of an event? Not like you’re doing austere ops out of dirt strips where you’re gnats assing it. 

There is one mission set where yes, TOLD in the Buff is vitally important. Read into that what you will. 

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