jgore
Posts: 518
Joined: Sun Feb 17, 2002 2:41 am

I Thought Engines Are Parallel Aligned To Fuselage

Mon Nov 11, 2002 12:14 pm

Looking at this picture, I noticed that engines are not parallel aligned to the fuselage. Instead, they seem to be in-bound aligned.
Am I correct ? . If so, why they are installed that way ?, Is this a common pattern in all aircrafts ?.


View Large View Medium
Click here for bigger photo!

Photo © Tim Samples


Regards

Jgore  Smile
 
AJ
Posts: 2295
Joined: Wed Nov 03, 1999 3:54 pm

RE: I Thought Engines Are Parallel Aligned To Fuselage

Mon Nov 11, 2002 12:48 pm

Yes, you're correct. 'Toeing' in of wing mounted engines reduces stresses on the wing root allowing lighter structures to be used.
 
Guest

RE: I Thought Engines Are Parallel Aligned To Fuselage

Mon Nov 11, 2002 12:50 pm

I'm not sure why the engines appear to mounted the way they are in this picture, but canting the engines on aircraft with aft mounted powerplants is almost universal. They are mounted with the engine inlets outboard a few degrees. One of the explinations that I remember from one of my type rating ground schools regarding the outward canting of the engines (as seen from the front) was to minimize the rudder forces required in the case of engine failure. Also, it's common to mount the engines on larger single-engine aircraft with a significant cant. Next time you get a chance go look at a late model Bonanza. It will really surprise you. You'd think the airplane would fly sideways through the air.

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

RE: I Thought Engines Are Parallel Aligned To Fuse

Mon Nov 11, 2002 2:28 pm

Typically the engines are canted to account for airflow and shockwaves from the fuselage; either to reduce drag, or increase effectiveness, or both.

The reason on the MD-80, for example, that the engines are distinctly canted upwards is to account for the airflow and it goes up over the wing and then down again.

Steve
 
nikes
Posts: 38
Joined: Mon Aug 27, 2001 9:26 am

RE: I Thought Engines Are Parallel Aligned To Fuselage

Tue Nov 12, 2002 12:48 pm

Wow ... i never knew that ... you would think that a component of thrust is "wasted" by having the engines like that.

-Nikes
 
jgore
Posts: 518
Joined: Sun Feb 17, 2002 2:41 am

RE: I Thought Engines Are Parallel Aligned To Fuselage

Wed Nov 13, 2002 6:14 am

Thanks for your 2 cents.

Regards

Jgore  Smile
 
bio15
Posts: 1048
Joined: Fri Mar 23, 2001 8:10 am

RE: I Thought Engines Are Parallel Aligned To Fuselage

Fri Nov 15, 2002 6:34 am

I have read posts about this question previously. The consensus was that it is due to the bow wave generated by the nose of the aircraft. It's like a boat moving through the water. You can see the lines of water forming an angle with the nose, as if it had caught a rope (not sure about the picture of that  Smile). With the planes it's the same thing but with air so you can't see it. And engines are tilted inward to meet the greatest amount of air which will be coming in that angled direction. Don't know if I was clear

-Alfredo
 
jgore
Posts: 518
Joined: Sun Feb 17, 2002 2:41 am

RE: I Thought Engines Are Parallel Aligned To Fuselage

Fri Nov 15, 2002 11:05 pm

You mean they take some air away from the nose in order to avoid the friction of the nose with the air ?

Jgore  Smile
 
bio15
Posts: 1048
Joined: Fri Mar 23, 2001 8:10 am

RE: I Thought Engines Are Parallel Aligned To Fuselage

Tue Nov 19, 2002 4:55 am

No, the air strikes the nose as usual. The nose splits the air and pushes it outward so the aircraft can penetrate, and the engine tilt is to catch the most of this deflected air.

Here you can see the water wave I mentioned. Notice the boat moves the water that way, same as aircraft move the air. Picture the kid with his arms extended and a pair of engines hanging down.  Smile



Saludos
-Alfredo
 
jgore
Posts: 518
Joined: Sun Feb 17, 2002 2:41 am

RE: I Thought Engines Are Parallel Aligned To Fuselage

Wed Nov 20, 2002 11:59 am

ohhhhh yeah, i got the point Big grin

Thank you very much

Jgore  Smile

Who is online

Users browsing this forum: Yahoo [Bot] and 17 guests