Sponsor Message:
Civil Aviation Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Qantas Boeing 744 With 6 Engines?  
User currently offlineFJWH From Netherlands, joined May 2004, 969 posts, RR: 3
Posted (10 years 7 months 22 hours ago) and read 13279 times:

I don't get this picture:


View Large View Medium

Photo © Steve Ruttley



Why does this plane got 3 engines?(in total 6 or?) Under the photo it says: "5th pod carried from Sydney to Singapore". I dont understand what the photographer mend by that so that maybe it. If you click the reg.number you get to see the same plane with normal 4 engines.
Can anyone please clear this up for me?

Thanks, FJWH

[Edited 2004-05-22 14:54:24]

[Edited 2004-05-22 14:56:48]


FlightS in the next 3 months: MSP, PHX, MEM, NCE, TFS, BCN. All round trips from AMS
48 replies: All unread, showing first 25:
 
User currently offlineSpeedbudgie From United Kingdom, joined Nov 2003, 112 posts, RR: 0
Reply 1, posted (10 years 7 months 22 hours ago) and read 13099 times:

An extra engine can be ferried from one location to another attached to the wing of a 747. This engine is merely hitching a ride and is not functioning in any way. This is not a particularly common practice, but is a convenient way to get an engine from point A to point B.

speedbudgie


User currently offlineHoons90 From Canada, joined Aug 2001, 3074 posts, RR: 52
Reply 2, posted (10 years 7 months 22 hours ago) and read 13103 times:
AIRLINERS.NET CREW
CHAT OPERATOR

The plane is ferrying a spare engine in order for another aircraft of the same airline to use it at that destination, incase a spare is needed...

Edit.. too late

[Edited 2004-05-22 14:58:24]


The biggest mistake made by most human beings: Listening to only half, understanding just a quarter and telling double.
User currently offlineGreasespot From Canada, joined Apr 2004, 3086 posts, RR: 20
Reply 3, posted (10 years 7 months 22 hours ago) and read 13015 times:

They are transporting a spare engine . That is how they can do it on the 747. Somewhere in the system they need a engine and use the 747 to carry it.

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?"
User currently offlineStevenUhl777 From , joined Dec 1969, posts, RR:
Reply 4, posted (10 years 7 months 21 hours ago) and read 12669 times:

United Airlines used to do the exact same thing...maybe they still do, not sure.

User currently offlineTheflcowboy From United States of America, joined Jan 2004, 405 posts, RR: 0
Reply 5, posted (10 years 7 months 20 hours ago) and read 12548 times:

Wasnt there a UA DC-10 years ago that had to make an emergency landing because of the 4th pod?


A318, A320, A332, A333, B1900, B722, B732, B733, B734, B735, B737, B738, B772, CR1, CR2, CR7, CR9, MD80, MD81, MD82, MD8
User currently offlineJblake1 From United States of America, joined Aug 2003, 293 posts, RR: 0
Reply 6, posted (10 years 7 months 20 hours ago) and read 12409 times:

Wouldn't a extra engine that is not providing thrust create a lot of extra drag? Obviously not enough to prevent safe operation, but would I be right assume that the fuel burn rate would be significantly higher?

User currently offlineDfwRevolution From United States of America, joined Jan 2010, 1001 posts, RR: 51
Reply 7, posted (10 years 7 months 20 hours ago) and read 12249 times:

Obviously not enough to prevent safe operation, but would I be right assume that the fuel burn rate would be significantly higher?

Since an extra engine is carried very rarely and not part of standard opperation I think that, while fuel burn would be increased, it would be acceptable. There are not many ways to transport large turbofan engines, and if an aircraft is grounded because of powerplant issues, it is costing more money than a little bit of drag

[Edited 2004-05-22 16:47:27]

User currently offlineAirplanetire From United States of America, joined May 2001, 1809 posts, RR: 2
Reply 8, posted (10 years 7 months 20 hours ago) and read 12179 times:

How significantly is the fuel burn increased? Could a 747 with spare engine make a longer flight such as LAX-SYD nonstop?

-Airplanetire


User currently offlineFrancoflier From France, joined Oct 2001, 3838 posts, RR: 11
Reply 9, posted (10 years 7 months 20 hours ago) and read 12074 times:

Hey! That's fun stuff!

First time I ever saw or heard about that rarity.

But how is the engine attached to the structure? is there a special pylon that has been designed for the occasion, or does the plane originally carry provision to attach an extra pylon underneath the wing?

Can it carry other types of engine, or just the one the a/c uses?

Intersting stuff, really.



Looks like I picked the wrong week to quit posting...
User currently offlineVSXA380X800 From United Kingdom, joined May 2004, 421 posts, RR: 1
Reply 10, posted (10 years 7 months 19 hours ago) and read 11875 times:

Three questions

1. Is that aircraft particularly made for these transport or all 747s capable of this ?
2. If the 747 had 5 engines wouldn't the aircraft be unbalanced ?
3. Now if the aircraft had 6 engines, wouldn't the wings AND the aircraft be heaver and be harder to maneuver?



4 decks 4 engines 4 long haul
User currently offlineBlooBirdie From Lesotho, joined Sep 2003, 261 posts, RR: 0
Reply 11, posted (10 years 7 months 19 hours ago) and read 11789 times:

Spare engine transport happens quite often; here's another example:


View Large View Medium
Click here for bigger photo!

Photo © Don Boyd



User currently offlineFrancoflier From France, joined Oct 2001, 3838 posts, RR: 11
Reply 12, posted (10 years 7 months 19 hours ago) and read 11774 times:

And finally, can you carry pax on those such flights?

Are there any other restrictions/limitations involved?

That's a lot of questions now, hopefully someone around here knows about all that stuff...



Looks like I picked the wrong week to quit posting...
User currently offlineL.1011 From United States of America, joined Aug 2001, 2209 posts, RR: 9
Reply 13, posted (10 years 7 months 19 hours ago) and read 11647 times:

How significantly is the fuel burn increased?

It depends. If the engine is like that, allowing the blades to spin without power (windmilling) then the increase is significant. If a streamlined cover is fitted (pics in the database) then it's rather negligable.

Could a 747 with spare engine make a longer flight such as LAX-SYD nonstop?

LAX-SYD is already cargo-restricted on a base 744 AFAIK, cargo would be even moreso with the ferry engine. A 744ER, which can fly the route without cargo restriction normally, would have one carrying the engine. On less demanding routes like LAX-NRT, there would be no problem.


But how is the engine attached to the structure? is there a special pylon that has been designed for the occasion, or does the plane originally carry provision to attach an extra pylon underneath the wing?

There is provision for a pylon there AFAIK.

Can it carry other types of engine, or just the one the a/c uses?

I've only seen aircraft carrying their own engine type. I would assume any engine would be possible, but the only airplanes that I believe can do it are 747s and DC-10s, which use the same basic engines. With narrowbodies, they wouldn't be far enough away from home to need the extra engine, and the only widebodies that don't use the same basic CF6/RB211/Trent/PW4000 family are the A340 (which can't carry a 5th) and the 777 (which can't carry a third because the engines are too frickin' big)

Is that aircraft particularly made for these transport or all 747s capable of this ?

I would assume it is a factory-optional feature, like selecting a different engine type or additional fuel tankage. It seems to be something the majority of airlines, especially ones that fly to some seriously far-out destinations (like Air France and the various overseas departments) would select.

If the 747 had 5 engines wouldn't the aircraft be unbalanced ?

No because the 5th isn't running and the drag concequence is negligable, and could be cured by tapping the other side's throttles back a tad from the side carrying the engine, or by FADEC (full-authority digital engine control) automatically.

Now if the aircraft had 6 engines, wouldn't the wings AND the aircraft be heaver and be harder to maneuver?

I don't believe the 747 or DC-10 (the other plane that can do this) is certified to carry 6/5 engines.

And finally, can you carry pax on those such flights?

Absolutely. It's not an inherantly dangerous procedure, which is the criteria that blocks passengers off planes.

Are there any other restrictions/limitations involved?

If the plane is at the edge of its performance envelope as far as range/payload, then yes, one or the other would be restricted. If we're talking about a 744 on JFK-LHR, then no.


User currently offlineFrancoflier From France, joined Oct 2001, 3838 posts, RR: 11
Reply 14, posted (10 years 7 months 19 hours ago) and read 11526 times:

Thanks for the repliy L1011! interesting thread really.

I can imagine that more than a few passengers got a real surprise when they looked out the window and saw THAT prior to their take off!

Especially since it's not running...

How heavy is your common CF6/PW4000 by the way?

I see it carries a protection around the intake... Interesting...

Is the engine windmilling all the time (at least the fan spool) or is it blocked somehow?

If it windmills, how greatly does it affect drag?



Looks like I picked the wrong week to quit posting...
User currently offlineVSXA380X800 From United Kingdom, joined May 2004, 421 posts, RR: 1
Reply 15, posted (10 years 7 months 19 hours ago) and read 11522 times:

''No because the 5th isn't running and the drag concequence is negligable''

So what you are trying to say is that, If a A340-600 ( for example) has only three engines running it will reduce drag and will be unbalanced ?



4 decks 4 engines 4 long haul
User currently offlineMD-90 From United States of America, joined Jan 2000, 8508 posts, RR: 12
Reply 16, posted (10 years 7 months 19 hours ago) and read 11419 times:

No, the A346 will have asymmetric thrust vectors. But yes, it would be "unbalanced", in a way, but it has nothing to do with drag.

The fifth engine pod is tucked away pretty close to the fuselage already. The rudder is plenty powerful enough to offset it. Or the thrust levels could be managed appropriately, as L.1011 mentioned.


User currently offlineJBirdAV8r From United States of America, joined Jun 2001, 4491 posts, RR: 21
Reply 17, posted (10 years 7 months 19 hours ago) and read 11359 times:

2. If the 747 had 5 engines wouldn't the aircraft be unbalanced ?

Not really. The lateral displacement from the CG would create a very minimal moment, so the aircraft would not be "unbalanced"



I got my head checked--by a jumbo jet
User currently offlineVSXA380X800 From United Kingdom, joined May 2004, 421 posts, RR: 1
Reply 18, posted (10 years 7 months 18 hours ago) and read 11222 times:

Sorry but I have A LOT of questions to ask and things to say  Smile

Since the engine is not in use, why isn't it stored in the cargo under belly than out side( like cargo airlines do). It kind of increases complication for the pilots.
If the Engine would be carried in the underbelly, you can do two things at once, carry passengers and bring the engine to the other location at the same time.
''lateral displacement from the CG''
Can you explain ?

Thanks



4 decks 4 engines 4 long haul
User currently offlineAirTran737 From United States of America, joined Apr 2004, 3707 posts, RR: 12
Reply 19, posted (10 years 7 months 18 hours ago) and read 11218 times:
Support Airliners.net - become a First Class Member!

I can just see the new Virgin Slogan....Five engines for ultra long haul.


Nice Trip Report!!! Great Pics, thanks for posting!!!! B747Forever
User currently offlineMD-90 From United States of America, joined Jan 2000, 8508 posts, RR: 12
Reply 20, posted (10 years 7 months 18 hours ago) and read 11156 times:

VSX, it's simple. The engine won't fit!

Lateral CG displacement - a shift in the cg from side to side, rather than the typical front to rear.

You know, like how those MD-80s should be dreadfully unbalanced from having 2 seats on one side of the aisle and 3 seats on the other? Big grin


User currently offlineVorticity From United States of America, joined May 2004, 337 posts, RR: 5
Reply 21, posted (10 years 7 months 18 hours ago) and read 11130 times:

A 5th engine would increase drag on that side, as well as change the dynamics of the aircraft. The extra engine is held close to the fuseloge to reduce the moment on the aircraft (lateral displacement from the cg). The farther they place it from the cg, the greater the effect it would have on the aircrafts dynamics, because it would create a greater about the cg. My dynamics book is at work, otherwise I could be more specific  Smile

I'm assuming since they do it, it's been well studied, and they can compensate for the changes in drag and dynamics with the control surfaces.



Thermodynamics and english units don't mix...
User currently offlineStearmanNut From United States of America, joined Apr 2004, 352 posts, RR: 0
Reply 22, posted (10 years 7 months 18 hours ago) and read 11040 times:

So...It is a 747 with FIVE engines...


If wishes were horses, a Tail Dragger I would fly...
User currently offlineVSXA380X800 From United Kingdom, joined May 2004, 421 posts, RR: 1
Reply 23, posted (10 years 7 months 18 hours ago) and read 10999 times:

MD-90, Vorticity,
Thanks I understand now. So that the reason why the engine is not placed between engine one and two. This is the last question ( I hope) .Is the extra phylon only on the left wing or on both ?



4 decks 4 engines 4 long haul
User currently offlineMexicana757 From United States of America, joined Apr 2001, 3047 posts, RR: 29
Reply 24, posted (10 years 7 months 18 hours ago) and read 10968 times:

Theflcowboy

Yes, an UA DC 10 had to make any emergency landing because of the 4th pod. The flight was a schedule flight from ORD-HNL. The airplane had to return to ORD. It happened sometime in the early to mid 1990s. I can't remember that well, but I think weather played a role.


25 Vorticity : Thanks I understand now. So that the reason why the engine is not placed between engine one and two. This is the last question ( I hope) .Is the extra
26 Burg400 : The first time I saw a 747 with 5 engines was in Singapore back in 1979 it was a BA flight which was taking us onto Sydney. The day before on climbing
27 Post contains images Leezyjet : The lateral c of g is normally acheived by loading the same amount of fuel in each wing. With a 5th pod attatched, you simply add the equivelant weigh
28 Garnetpalmetto : If the Engine would be carried in the underbelly, you can do two things at once, carry passengers and bring the engine to the other location at the sa
29 Mu2 : Maybe they messed up when writing the MEL and put 5 engines on the form. OOPS!!!
30 Mu2 : Do they put this on the carousel at baggage claim?
31 Smcmac32msn : Do they put this on the carousel at baggage claim? Do they tie it to the top of the cab, or use it instead of the cab's motor? Maybe they can get it i
32 TG992 : A few points of interest.. It appears GE powered 747 aircraft can't ferry a fifth pod. As a general rule, a fifth pod operation will attract a 15% inc
33 Francoflier : I know much more about props than jets, thus there's something I'd like to know. Question: Does a windmilling jet engine (say one of those CF6 or PW40
34 Post contains images Soaringadi : **** "Could a 747 with spare engine make a longer flight such as LAX-SYD nonstop?" **** first of all the spare engines do not work when being carried.
35 Post contains images Vorticity : Question: Does a windmilling jet engine (say one of those CF6 or PW4000 ) produce more drag than if the compressors were not rotating? I guess this wo
36 MD-90 : You know I can't recall ever seeing any (pictures of) ferries other than modern Rolls and the early Pratts on the 747. Francoflier, I think the main t
37 ZK-NBT : Soaringadi, yes QF and UA do operate LAX-SYD nonstop already, but the original question asked weather they could do it when carrying a fifth pod. See
38 Francoflier : Yeah, that was my question msince apparently there's an odd shaped cover on. It has to be for drag and to prevent the engine from windmilling. I know
39 Post contains images Soaringadi : Ohh.... I mistook it.... I'm sorry ZK-NBT, and airplanetire weather is good
40 Gigneil : L-1011s could also carry a 4th RB211 underwing. N
41 123 : Years ago (around end '70's) LH had a big report about this matter. The explanation is simple. The engine is needed urgently and there is no cargo cap
42 JMChladek : I don't know if it would even be necessary to carry a spare engine from Syndey to LAX. LAX and SFO have pretty good sized maintenance facilities and I
43 VirginFlyer : JMChladek - that may not necessarily be true - I don't believe there are any American operators of the specific engine in question for the bulk of Qan
44 Gemuser : Its called a 5th pod kit and is a standard option kit on the 747 line as it was on the 707 line before it. I have pictures of both Qantas 742 & MSA (M
45 NZ1 : There is NO restriction on the carrying of passengers with the fifth pod activated. I am pretty sure that only RR engines can be fifth podded. The sta
46 N9801F : Do I remember that on DC-8's (with the old JT-3 engines), the 'extra' engine was encapsulated in a little bullet-shape carrier? (The engine was comple
47 NZ1 : Virginflyer, sorry to be picky but the engine on the bulk of the QF 744 fleet is the RB211-524HT not the -524G (slight thrust difference). The rest of
48 ScottysAir : is that something going on about engines with B747-400?
Top Of Page
Forum Index

This topic is archived and can not be replied to any more.

Printer friendly format

Similar topics:More similar topics...
Boeing 744 With 287 Seats... Money Making? posted Thu Jun 21 2007 08:28:20 by Ansett767
First Boeing 787 With Genx Engines posted Thu Feb 16 2012 14:23:38 by OD-BWH
Qantas Having Problems With The 744`s? posted Mon Sep 11 2006 01:08:05 by Qantas744ER
Why China Airlines 744 With Boeing Colors? posted Wed Sep 6 2006 19:38:14 by RedFlyer
How Boeing Did With The 744 EIS Delay? posted Wed Jun 14 2006 20:47:01 by FCKC
Question: Can Boeing Replace 744 With Larger Twin? posted Tue Jun 21 2005 18:15:21 by DAYflyer
BA 744 Flies LAX-MAN With 3 Engines...WITH Pax! posted Fri Feb 25 2005 02:51:17 by Pacific
What Your Favorite Engines On Your Boeing 744 posted Mon Feb 25 2002 17:00:16 by Baec777
Qantas Fleet Talks With Boeing,Airbus posted Mon Sep 24 2001 10:56:39 by Wirraway
744 With PW "screamer" Engines? posted Mon Jan 15 2001 23:22:26 by Qantas747-sp