B747 performance with 5th engine
Thread Starter

Joined: Mar 2019
Posts: 77
Likes: 15
From: Prague
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.
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.

Joined: Feb 2017
Posts: 1,013
Likes: 15
From: Isla Grande
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.
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.
747-400 That Flew With A 5th (Spare) Engine

Joined: Jul 2005
Posts: 319
Likes: 96
From: Honolulu
Boeing 747-132(SF) - American International Airways - Kalitta | Aviation Photo #0224038 | !!!!!!!!!!!!!!
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.
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.
Joined: May 2008
Posts: 451
Likes: 0
From: Scotland

Joined: Feb 2017
Posts: 1,013
Likes: 15
From: Isla Grande
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.
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.

Joined: Oct 2000
Posts: 81
Likes: 0
From: CYXY YT, Whitehorse Canada
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.
Joined: Jan 2004
Posts: 1,068
Likes: 4
From: Hiding..... in one hemisphere or another
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.

Joined: Oct 2000
Posts: 81
Likes: 0
From: CYXY YT, Whitehorse Canada
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.




