KLAX
Topic Author
Posts: 1568
Joined: Fri Oct 05, 2007 7:59 am

A340-600 Inboard Engines Point Down? Why?

Fri Mar 07, 2003 2:56 am

I noticed the other day that the inboard engines on the A340-600 point downwards compared to the outboards. What is the reson behind this?

-Clovis

http://www.airliners.net/addphotos/big/ready/FWWCA34060014R.jpg
 
Leezyjet
Posts: 3541
Joined: Sun Oct 14, 2001 7:26 am

RE: A340-600 Inboard Engines Point Down? Why?

Fri Mar 07, 2003 4:37 am

That link does not work - try again and insert the picture if you can so we can see what you mean.

I work with the A346 just about every day, and to be honest I can't say I've ever noticed, although they do sit pretty low to the ground, I'll have a look next time I'm in ( but not for 2 weeks tho - on holiday now) Big grin

The only reason I can think of based on your description is that aircraft in general fly in a slightly nose up attitude, so then the slight downward angle on the engines would mean that they are able to achieve maximum airflow in the cruise as they would be paralel to the oncoming airflow, which after all is where they spend most of their running time.

Just my thought's.

 Smile
"She Rolls, 45 knots, 90, 135, nose comes up to 20 degrees, she's airborne - She flies, Concorde Flies"
 
Klaus
Posts: 20622
Joined: Wed Jul 11, 2001 7:41 am

RE: A340-600 Inboard Engines Point Down? Why?

Fri Mar 07, 2003 4:58 am

The weird thing is that the outboard and the inboard engines have a different tilt; But as far as I know, it´s indeed due to different airflow at the respective positions.

Just a little strange aesthetically...  Wink/being sarcastic


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Photo © Thomas Klein

 
KLAX
Topic Author
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RE: A340-600 Inboard Engines Point Down? Why?

Fri Mar 07, 2003 6:17 am

Okay, the picture was accepted right after I posted Big grin


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Photo © Clovis Bouhier



You can really see it there^^

-Clovis
 
sllevin
Posts: 3312
Joined: Wed Jan 30, 2002 1:57 pm

RE: A340-600 Inboard Engines Point Down? Why?

Fri Mar 07, 2003 9:19 am

I'd be willing to bet that in flight, as the wingtips flex upwards and the wing "warps" a little, the outboard engines align quite similarly to the inboards, and most favorably into the airflow.

Steve
 
manzoori
Posts: 1459
Joined: Sun Sep 22, 2002 7:08 am

RE: A340-600 Inboard Engines Point Down? Why?

Sat Mar 08, 2003 3:03 am

Steve,

I'd have thought so too but in this shot the inboard engine still looks like it points down compared to the outboard engine


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Photo © Sung-Yang Tong



The mystery continues! I'll ask my Airbus colleagues at work on Monday and see if they have any clues.

Cheers!

Rez
 Wink/being sarcastic
Flightlineimages DOT Com Photographer & Web Editor. RR Turbines Specialist
 
Klaus
Posts: 20622
Joined: Wed Jul 11, 2001 7:41 am

RE: A340-600 Inboard Engines Point Down? Why?

Sat Mar 08, 2003 3:38 am

The same effect can be seen on other aircraft types as well; In many cases, the engines are canted horizontally rather than vertically. And the only reason I know of is indeed the airflow at the location where the engines are mounted.

There is no benefit to mounting the engines pointing straight forward if the airstream in cruise doesn´t follow the same straight line (due to the "bow wave" created by the fuselage, for instance).

It had been discussed in this thread before:
http://www.airliners.net/discussions/tech_ops/read.main/30558/4/
 
KLAX
Topic Author
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RE: A340-600 Inboard Engines Point Down? Why?

Sat Mar 08, 2003 4:34 am

Thanks for the info Klaus. Still a great looking plane...I had some more shots of it accepted today, including a landing Big grin

-Clovis
 
Klaus
Posts: 20622
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RE: A340-600 Inboard Engines Point Down? Why?

Sat Mar 08, 2003 4:45 am

She´s a beauty, indeed! Big grin

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