JayinKitsap
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New Engines On Older Planes

Wed Apr 26, 2006 5:33 am

In the IAG Portal
http://iagportal.squarespace.com/iag...4/17/new-life-for-an-old-bird.html

it discusses putting new engine models on older planes. Assuming the engine is already certified and in production, what does it take to design and certify a new engine for a given plane. This article discussed the MD-80 getting reengined with the BR715 that was used on the 717.

Do the thrusts always have to match, or can a higher thrust be used. I'm thinking of the GE NxGn for the 748 being retrofitted to the 767. If higher thrust can the MTOW be increased provided the gear is acceptable.

Can the 744 be reengined with the same when going thru conversion to a freighter?

What is the typical life of a modern engine? I confess I don't know but I would expect that a plane would require several engine replacements during its life.

Thanks for your input.

Jay
 
pilotpip
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RE: New Engines On Older Planes

Wed Apr 26, 2006 11:05 am

There are a few re-engining projects that have taken place. The most notable is probably the DC-8-70 with the CFM-56. UPS has a number of them. 727s have a number of them. UPS has RR (speys or tays, can't remember) on their 727-100s. Another one that is less frequent is Pratt JT8D-200s on a 727-200. There are a few out there and they're pretty noticable based on the much larger fuselage mounted engines.

There are a ton of considerations. Weight and balance changes, rigging, equipment locations (accessory drives, Fuel Control units, etc). And also aerodynamic considerations for both the aircraft and new engine.

In most cases, it's not a cost-effective solution. You have to have the aircraft re-certified and that is a very, very expensive procedure.
DMI
 
FredT
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RE: New Engines On Older Planes

Thu Apr 27, 2006 3:31 am

I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
texfly101
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RE: New Engines On Older Planes

Thu Apr 27, 2006 6:45 am

Take a look at the KC-135 and the B-52. Both were re-engined with larger, more powerful fuel efficient engines. Both resulted in an aircraft that had higher performance and enhanced efficiencies. There's gotta be a lot of life left in the frame and a economic reason for it to happen. The TF33 on the B-52H increased the combat radius over 600 miles. The KC-135 replacement CFM56 gave a 27% fuel savings. But since then, every proposal for the B-52 has been turned down as not cost effective enough considering frame life and projected sorties. The KC-135 re-engine will be a possiblity under the new AF Tanker project. While all the news is about the projected A vs B battle, this is actually considered to be a three way race if the re-engine makes economic sense. I'm sure Senator McCain will make sure of that.
 
Dougloid
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RE: New Engines On Older Planes

Thu Apr 27, 2006 9:03 am

Quoting Pilotpip (Reply 1):
There are a few re-engining projects that have taken place. The most notable is probably the DC-8-70 with the CFM-56. UPS has a number of them. 727s have a number of them. UPS has RR (speys or tays, can't remember) on their 727-100s. Another one that is less frequent is Pratt JT8D-200s on a 727-200. There are a few out there and they're pretty noticable based on the much larger fuselage mounted engines.

As far as notable I'd say the CV440/580 was one of the most successful re-engining programs ever. One of my homies was an electrical tech at Pacific` Airmotive and he says they figured they'd maybe do ten or fifteen at most.

Also when I worked for Garrett we did a few-the 731 Jetstar and the 731 DH125 both of which went well over a hundred frames each. The 731 Jetstar had a lot of the engineering done by Swearingen (SWACO) and it was so successful Lockheed built the Jetstar II
If you believe in coincidence, you haven't looked close enough-Joe Leaphorn
 
pilotpip
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RE: New Engines On Older Planes

Thu Apr 27, 2006 12:29 pm

Yeah, there are a few bizjets that have engine swaps available. 731s are available for Falcon 20s and Sabreliners. Then there's the eagle mod for Citation Is that puts a Williams engine on those. There are various upgrades for PT-6 applications where you put a "better" hotsection in for more power, either flat-rated which gives you more at altitude, or overall.
DMI
 
Tristarsteve
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RE: New Engines On Older Planes

Thu May 04, 2006 6:35 pm

Quoting JayinKitsap (Thread starter):
What is the typical life of a modern engine? I confess I don't know but I would expect that a plane would require several engine replacements during its life.

A modern engine will stay on the wing for around 30000hrs or 6-10 years

Quoting JayinKitsap (Thread starter):
Can the 744 be reengined with the same when going thru conversion to a freighter?

A lot of RB211-524H on B744 have been refitted with a HP module from the Trent engine making the RB211-524GT. The engine then runs about 50 degC cooler which gives it a much longer life.
But to say fit a PW4000 on a RB211 engined jumbo is a massive exercise and would never be economical.
 
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Zkpilot
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RE: New Engines On Older Planes

Fri May 05, 2006 12:22 am

Quoting JayinKitsap (Thread starter):
Do the thrusts always have to match, or can a higher thrust be used. I'm thinking of the GE NxGn for the 748 being retrofitted to the 767. If higher thrust can the MTOW be increased provided the gear is acceptable.

Whilst size and thrust, weight issues would be fine, isn't the new engines going to be bleedair less? Whilst the 748 will be designed around this issue, the 767 would have to be modified quite a bit to take this unless that engine can be fitted with air bleed...?
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jeffry747
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RE: New Engines On Older Planes

Fri May 05, 2006 4:53 pm

Quoting Pilotpip (Reply 1):
UPS has RR (speys or tays, can't remember) on their 727-100s.

UPS 721's are equipped with Rolls Royce Tays.

I don't think you can call this a re-engining program, but look at what Boeing did with the 737. They pretty much took the 737-200, ditched the JT-8s, slapped on a pair of CFM-56's, stretched the fuselage a little bit, and called it the 737-300.
C'mon Big B, FLY!
 
474218
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RE: New Engines On Older Planes

Sat May 06, 2006 12:10 am

You can't just changes engines types with out first having done extensive engineering, planning and even flight testing. Even changing between different models of the same engine requires paper work and a regulatory agency approval. L-1011's were built with both RB-211-22B engines and RB-211-524 engines. However, if I own a -22B powered L-1011 I can't buy three -524's and install them. It takes a Lockheed service bulletin to accomplish the change. This service bulletin allows for the engine change and lists about a dozen additional service bulletins that also must be accomplished along with fitting the new engines. I also have to pay Lockheed to use their service bulletin.
 
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litz
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RE: New Engines On Older Planes

Sat May 06, 2006 12:32 am

Another re-engineing program is the C5-M; they're essentially putting CF6's on the C5. Last I heard, they were in the engine-runup stage (they successfully managed engine starts a couple of months ago) with a goal of first test flight something this spring.

On the MD80->BR715 article at the top of this thread, while the two engines are essentially identical in terms of thrust and weight, I'm pretty sure the 715 is a FADEC engine; this would require some hefty avionics changes to mount it on a FADEC-less MD80, would it not?

- litz
 
Devilfish
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RE: New Engines On Older Planes

Sat May 06, 2006 8:58 am

For a sample that made the news (unflattering) a while back.....  Smile

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KC135R
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RE: New Engines On Older Planes

Sun May 07, 2006 9:57 pm

Quoting Texfly101 (Reply 3):
Take a look at the KC-135 and the B-52. Both were re-engined with larger, more powerful fuel efficient engines. Both resulted in an aircraft that had higher performance and enhanced efficiencies.

Just to clarify....

The B-52H, unlike the KC-135, was not re-engined. The B-52H does have different engines (TF-33's) than all previous versions of the airplane (all of which had some variation of the J-57 engine) but the "H" model was built like that, not changed later on.

On the other hand, the KC-135A was built with J-57 engines which were later removed and swapped to either TF-33's (KC-135E) or CFM-56's (KC-135R).
 
nitrohelper
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RE: New Engines On Older Planes

Mon May 08, 2006 8:59 am

Is it possible to put a bigger thrust,late model engine (any make) on the DC-9-30s.
I am looking at a business jet built on a 9-30 airplane. How much can we "hot rod" it ?.
Could we put two 717 pushers on it ? Anybody with a rough cost estimate, the plane is ready for a major check, so now is the time to re-engine if feasible and has some benefits

Thanks for any help.  idea  PS :If the idea is nuts ,tell me ,we can fly it "as is" .
 
Devilfish
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RE: New Engines On Older Planes

Mon May 08, 2006 9:31 am

Quoting Nitrohelper (Reply 13):
I am looking at a business jet built on a 9-30 airplane. How much can we "hot rod" it ?.

This would probably be not too cost effective, and at the end of the day you would have a relatively older airframe. Brand-new jet engines don't come cheap, nor the conversion work and certification of the new combination. It might be better to acquire a 717 available for sale from failing airlines, or coming off lease then changing the interior. Boeing tried the 717 Business Express but it was too short-legged to attract buyers. I don't know how much range extension could be achieved by an after-market modification.
"Everyone is entitled to my opinion." - Garfield
 
kaddyuk
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RE: New Engines On Older Planes

Mon May 08, 2006 10:52 am

Quoting Pilotpip (Reply 1):
aircraft re-certified and that is a very, very expensive procedure.

Anything to do with aircraft and the word "certify" is very very expensive... A license to print money if you will... :P
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JayinKitsap
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RE: New Engines On Older Planes

Mon May 08, 2006 1:36 pm

Quoting Zkpilot (Reply 7):
Whilst size and thrust, weight issues would be fine, isn't the new engines going to be bleedair less? Whilst the 748 will be designed around this issue, the 767 would have to be modified quite a bit to take this unless that engine can be fitted with air bleed...?

I was thinking of say using the GEnX for the 747-8 which will have bleed air replacing a GE CF6-80C2 on the existing plane. Obviously doing a few 767 or 747 wouldn't make sense, it would need to be like 50 or 100 to cover the certification cost. I am sure it is an endeavor like doing a 747 BCF.

It would also have to be select candidates that are due for new engines but have 6 to 12 years of life on the plane.
 
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kc135topboom
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RE: New Engines On Older Planes

Mon May 08, 2006 7:53 pm

Reengining alone will not increase the MTGW of an airplane. Both the KC-135 and DC-8-60 series had to have other modifications to increase the gross weight. Landing gear, brakes, etc.
 
greasespot
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RE: New Engines On Older Planes

Tue May 09, 2006 7:44 am

Well a few of the systems that need to be changed......

All the cockpit engine istruments

All the engine black boxes in the E & E bay

All the cables and routing

A lot if the ducting will also have to be changed

New pylon and nacelle

Plus buying two new engines ( i read some where that a CFM engine costs 5-7 million to buy each, not sure of the reliability of that infobut it is going to be costly)

paperwork change...For example to put -17 engines on te B737-200, an aircraft that is certified for -17's already, just not listed on the type certificate of the Actual airplane (previous operator did not buy it with the -17 capability) Boeing charged 250k USD. Imagine the cost to go to another engine type.

There is a reason that for the most part re-engining programs are failures.....It is to expensive and not worth it for an old airframe

The only way to re-coup the expenses is to sell up grade kits. NO one is willing to pay for engine upgrades on old airframe, and those who are usually can just buy a more modern airplane. Those who cannot buy a more modern airframe probably do fly enough to make the upgrade cost effective.


25-50 million buys a lot of fuel!!!
GS

[Edited 2006-05-09 00:45:32]

[Edited 2006-05-09 00:48:10]
Sometimes all you can do is look them in the eye and ask " how much did your mom drink when she was pregnant with you?"
 
wingscrubber
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RE: New Engines On Older Planes

Tue May 09, 2006 8:00 am

This is my favourite- a Dak with turboprops  Smile

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Arrow
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RE: New Engines On Older Planes

Tue May 09, 2006 9:25 am

Most famous and effective re-engining project was replacing Allisons with RR Merlins on the P-51. Took a mediocre performer and turned it into a world beater.
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