747400sp
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Why On 727 Re Engine With JT8 219

Tue Dec 12, 2006 9:14 am

I know the super 27 program is a 727 with JT8 217. But why they did not chose JT8 219. The JT8 219 has a bigger fan and is more powerful. So I would think it would be better for an engine for a re-engine 727 .
 
greasespot
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RE: Why On 727 Re Engine With JT8 219

Tue Dec 12, 2006 9:29 am

The re-engining was not about power. Hell a JT8D-15 will make a B727 fly at max weight.

The super 27 was about fuel effiency and noise(noise was the big part). A bigger and more powerful engine would have just cost more(to buy) for no more benifit. Plus that extra power comes with greater fuel burn..... it would have used more fuel to carry the same weight as the -217.

GS
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?"
 
flametech21
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RE: Why On 727 Re Engine With JT8 219

Tue Dec 12, 2006 10:06 am

It can be replaced with a 219, just isn't standard practice. Straight from the PW website:

Quote:
The -200 is also the exclusive power for the Super 27 re-engining program, in which Pratt & Whitney, in cooperation with Goodrich Aerostructures, is offering 727 operators a solution to achieve Stage 3/Chapter 3 compliance with improved performance. It involves replacing the two outboard engines with new JT8D-217C/219 models and adding noise suppression equipment to the center engine. The Super 27 can increase range up to 1,200 nautical miles and permits carrying up to 30 more passengers or up to 10,000 pounds in additional cargo.

The 219 usually isn't chosen because of the greater size and weight. It can be done, but requires heavier modifications to the engine mount structure to support it. Plus, the 219 is really overkill, as the increase in thrust is not necessary. That means that the 219 would actually burn more fuel than the 217 because of the additional structure weight.

The only time the 219 would be favored would be when the extra increase in thrust was wanted.
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113312
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RE: Why On 727 Re Engine With JT8 219

Tue Dec 12, 2006 11:40 am

All of the re-engined 727's at FedEx use the -217C. The center, no.2 engine, remains the -15/-17 that was originally on the plane. Even with the no.2 thrust reverser hardware removed, there was substantial additional weight in the rear associated with the bigger pod engines and their associated hydraulic reverser system. This additional weight was offset with ballast weights added to the forward pressure bulkhead.

The modified aircraft did achieve the desired Stage III noise certification as well as a boost in performance. Even with only two reversers, the stopping effect is superior to the standard "advanced" 727. Takeoff and climb performance is great too but you do have to watch out for two engine inop drift down consideration.
 
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LTU932
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RE: Why On 727 Re Engine With JT8 219

Tue Dec 12, 2006 3:30 pm

Slightly OT but still related to the 727, what about the 727QF which are operated by 5X? They were re-engined I believe with the Rolls Royce Tay (don't know which exact model). What exact modifications needed to be done for re-engining the 727 with the Tay, apart from what looks like removing the reversers from the number 2 engine? One thing that stung my eyes from seeing pictures of 5X 727s is that the QFs have a kind of hump on the number 2 engine intake, which, unlike regular JT8D powered 727s and even Super27s don't seem to have. A few pictures for comparison.

Upper Left: 727QF - Upper Right: non-re-engined 727
Bottom: Super27

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Photo © Frische Michael
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Photo © Frank C. Duarte Jr.



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Photo © Elliott Kefalas

Anyone know the mods a 727 had to get for re-engining with the Rolls Royce Tay?
 
FBU 4EVER!
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RE: Why On 727 Re Engine With JT8 219

Tue Dec 12, 2006 4:18 pm

Wrong! The -219 is NOT bigger than the 217C,or the basic -217 for that matter.The 217C and 219 are identical.The only difference is the position of a selector screw (or whatever the correct term is) on the fuel control unit that provides more thrust on the 219. Here in SAS we've got MD-80's with both types of engines.We pay Boeing/P&W a certain fee for a certain number of -219's.If we change this number it usually costs several thousand dollars.It takes just a few minutes to do the conversion.The engine data plates have -217C info on one side and -219 info on the reverse side.An adjustment on the FCU and turn the data plate and you've got either a -217C or a -219! Simple as that!
"Luck and superstition wins all the time"!
 
Blackbird
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RE: Why On 727 Re Engine With JT8 219

Wed Dec 13, 2006 4:26 am

Even a Super-27 with the -217's have an unreal climb-rate. It's actually superior to a 757 to my knowledge.
 
SlamClick
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RE: Why On 727 Re Engine With JT8 219

Wed Dec 13, 2006 4:55 am

Regarding the extra thrust, it is worth remembering that even the old "advanced" had engines (JT-8D-17) that would push the wings up to where they wouldn't fly anymore.

Huge differences between "altitude capability" and "maneuver capability" charts.

Probably quieter engines that produced no more thrust than the old -17s would still be worthwhile to install if they would extend the profitable life of this great old workhorse another ten years.
Happiness is not seeing another trite Ste. Maarten photo all week long.
 
ex52tech
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RE: Why On 727 Re Engine With JT8 219

Wed Dec 13, 2006 5:02 am

Quoting FBU 4EVER! (Reply 5):
Wrong! The -219 is NOT bigger than the 217C,or the basic -217 for that matter

Thank you, I was scratching my head thinking....was the -219 actually bigger than a -217, been over 10yrs since I touched an MD-80, I wasn't sure.

Quoting LTU932 (Reply 4):
One thing that stung my eyes from seeing pictures of 5X 727s is that the QFs have a kind of hump on the number 2 engine intake,

They had to have done that for airflow problems with the original JT-8 intake.
Not unlike the DC-10-40s, they have a "coke bottle" bulge in the #2 intake because of airflow differences between the CF-6s and the JT-9Ds.
The only real problem I could for-see with the RR mod, is now the airplane will have to make a stop over when it's tea time.
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LMP737
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RE: Why On 727 Re Engine With JT8 219

Wed Dec 13, 2006 5:42 am

Quoting Ex52tech (Reply 8):
Thank you, I was scratching my head thinking....was the -219 actually bigger than a -217, been over 10yrs since I touched an MD-80, I wasn't sure.

There the same size. AA has updated it's -217 to -219 standard. If memory serves me correctly the changes were basically with the fuel control and new fan blades. I'll do some research when I get a chance.
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LTU932
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RE: Why On 727 Re Engine With JT8 219

Wed Dec 13, 2006 6:43 am

Quoting Ex52tech (Reply 8):
They had to have done that for airflow problems with the original JT-8 intake.

OK, I see. What caused those airflow problems?

Quoting Ex52tech (Reply 8):
Not unlike the DC-10-40s, they have a "coke bottle" bulge in the #2 intake because of airflow differences between the CF-6s and the JT-9Ds.

It did actually remind me of the DC-10-40 and the MD-11, but then I opted not to compare them, as the DC-10 doesn't have the S-Duct design for the number 2 engine, like Boeing and Lockheed had. On the DC-10 and MD-11, the airflow goes straight into the engine, while on the L-1011 and 727, it passes through that S-Duct. It makes me wonder how that S-Duct affected the number 2 engine because I'm sure the Douglas design was much better suited in terms of airflow into the engine.

Quoting Ex52tech (Reply 8):
The only real problem I could for-see with the RR mod, is now the airplane will have to make a stop over when it's tea time.

 rotfl   rotfl   rotfl 
 
747400sp
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RE: Why On 727 Re Engine With JT8 219

Thu Dec 14, 2006 2:34 am

Quoting FBU 4EVER! (Reply 5):
Wrong! The -219 is NOT bigger than the 217C,or the basic -217 for that matter.The 217C and 219 are identical.

Thought the 217 had a 49 inch fan and the 219 had 55 inch fan. Maybe it is the 207 I am that thinking about, witch has the smaller fan.
 
A342
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RE: Why On 727 Re Engine With JT8 219

Thu Dec 14, 2006 3:42 am

Quoting LTU932 (Reply 10):
OK, I see. What caused those airflow problems?

I don't know exactly, but I suppose the RR Tay, having a higher bypass ratio, simply needs more air.



Today I happened to see a 722F-Super27 being offered for lease on www.speednews.com . That aircraft has -219s as outboard engines and a -17 center engine. Now that must be a rocket !
Exceptions confirm the rule.
 
FBU 4EVER!
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RE: Why On 727 Re Engine With JT8 219

Thu Dec 14, 2006 5:12 pm

747400sp: 217A,217C and 219 have the same diameter fan,but the A-version had different compressor blade shape.Also,the A used different alloys in it's construction and was unable to tackle the heat and stress of the uprated 217C/219.
"Luck and superstition wins all the time"!

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