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B747 performance with 5th engine

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B747 performance with 5th engine

Old 8th Oct 2019, 11:53
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B747 performance with 5th engine

Hello
I was looking for that on the Internet but I did not succed. Do you have or do you know how was performance of 747 affected while carrying 5th engine on the left wing?
I mean escpecialy how drag and fuel consumption were affected. I do not need all the charts. Just simple comparation for same weight and speed.
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Old 8th Oct 2019, 13:25
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Originally Posted by Rarife View Post
Hello
I was looking for that on the Internet but I did not succed. Do you have or do you know how was performance of 747 affected while carrying 5th engine on the left wing?
I mean escpecialy how drag and fuel consumption were affected. I do not need all the charts. Just simple comparation for same weight and speed.
Look here

747-400 That Flew With A 5th (Spare) Engine
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Old 8th Oct 2019, 15:49
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Boeing 747-132(SF) - American International Airways - Kalitta | Aviation Photo #0224038 | Airliners.net
Interesting read. This is about an engine removed a ferried inside due to cracks in pylon mounts.
It took engineering okay from Boeing and the FAA as well as weight and balance considerations.
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Old 8th Oct 2019, 19:48
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Originally Posted by gearlever View Post
In the 70s I worked for Iranair in Teheran. We regularly 5th podded engines to and from our overhauls in Frankfurt. On speaking to a captain regarding operating with the pod installed he said that basically they did not know it was there. I believe that 707s had a similar installation.
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Old 8th Oct 2019, 20:07
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Originally Posted by bcgallacher View Post

In the 70s I worked for Iranair in Teheran. We regularly 5th podded engines to and from our overhauls in Frankfurt. On speaking to a captain regarding operating with the pod installed he said that basically they did not know it was there. I believe that 707s had a similar installation.
Yep, the 707 did indeed have a similar installation.
But the comment of mentioned Iranair CPT doesn't cope with the article above.
Of course there are performance degredations concerning all phases of flight.

BTW, it was always a pleasure to work with Iranian colleagues. Very competent, well educated and nice people.
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Old 8th Oct 2019, 22:36
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there were a specific area in the FPPM for the 747-400 fitted with RR engines. so performances were affected. in the past some companies were publishing for the classic too. so the performance and dispatch were affected on the classic too.
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Old 9th Oct 2019, 04:13
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There is, or was, one page in the ops manual, and one or two in the performance manual. Essentially there is a there is a switch, if you will, in the electronics bay that tells the FMCs/ADCs about it. The ADCs will use reduced limits for speeds, I think around .78 mach. Max weights are reduced, and there's different trim settings to offset the yaw. The FMC will switch to a program that reflects the additional drag and performance penalties. All of the other limitations are in the perf manual. It was only ever available for JT9 and RB211's. The fan blades are all removed and there is an internal shroud to stop the engine from being rotated, so the lubrication system is generally removed. From what I've been told, it might be noticeable, but not hugely.
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Old 9th Oct 2019, 06:05
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Gear, thanks. Any chance we could find the page or two?
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Old 9th Oct 2019, 23:41
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Originally Posted by Atlas Shrugged View Post
There is, or was, one page in the ops manual, and one or two in the performance manual. Essentially there is a there is a switch, if you will, in the electronics bay that tells the FMCs/ADCs about it. The ADCs will use reduced limits for speeds, I think around .78 mach. Max weights are reduced, and there's different trim settings to offset the yaw. The FMC will switch to a program that reflects the additional drag and performance penalties. All of the other limitations are in the perf manual. It was only ever available for JT9 and RB211's. The fan blades are all removed and there is an internal shroud to stop the engine from being rotated, so the lubrication system is generally removed. From what I've been told, it might be noticeable, but not hugely.
i found in the fppm RR engines from pages 225 to 276 a little more than 2 pages .... never seen a ffpm for GE or PW engines mentionning the 5th pod only RR engines.
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