Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
Northwest727
Topic Author
Posts: 379
Joined: Sat Jul 30, 2005 10:38 am

MD-11 "Bent" Fuselage In Flight?

Sat Mar 03, 2012 11:11 pm

Hi everyone,

While I was looking at pictures of MD-11s, I noticed that in flight, the fuselage appears to "sag" down ahead of and behind the wings. Am I just going out of my mind and seeing things, or is this actually the case?


View Large View Medium
Click here for bigger photo!

Photo © Szabo Gabor
View Large View Medium
Click here for bigger photo!

Photo © Szabo Gabor


View Large View Medium
Click here for bigger photo!

Photo © Ben Wang



Thanks
 
User avatar
Starlionblue
Posts: 20798
Joined: Fri Feb 27, 2004 9:54 pm

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 1:13 am

Quoting Northwest727 (Thread starter):
While I was looking at pictures of MD-11s, I noticed that in flight, the fuselage appears to "sag" down ahead of and behind the wings. Am I just going out of my mind and seeing things, or is this actually the case?

It's not an illusion. Fuselages definitely sag like that. Just like a long plank would sag if you put it crosswise over an i-beam.
 
User avatar
Horstroad
Posts: 595
Joined: Thu Apr 08, 2010 8:19 pm

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 2:00 am

Yes fuselages bend. But it is hardly visible from this perspective the images show, at least I can not see it. Except for the curvature behind the wings. But if that's what you mean, that's just like the aft fuselage of the MD-11 is shaped, even on the ground.

This effect is well visible in this photo


View Large View Medium
Click here for bigger photo!

Photo © Daan Krans - AirTeamImages

 
User avatar
DocLightning
Posts: 22251
Joined: Wed Nov 16, 2005 8:51 am

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 3:06 am

The 777-300/ER is visibly bent in flight.
 
User avatar
DocLightning
Posts: 22251
Joined: Wed Nov 16, 2005 8:51 am

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 7:38 am


View Large View Medium
Click here for bigger photo!

Photo © ShaneShanghai
View Large View Medium
Click here for bigger photo!

Photo © William T Shemley


View Large View Medium
Click here for bigger photo!

Photo © Terry Wade
View Large View Medium
Click here for bigger photo!

Photo © Didier JH Goursolas

 
User avatar
n901wa
Posts: 472
Joined: Thu Oct 15, 2009 5:38 pm

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 3:20 pm

Its a carryover from the DC-10. Both the DC-10 and MD-11 had this bend/taper. From what I was told was it gives the nbr 2 eng a nose up angle with the spacing between the trunk and the top of the fues equal. You can see it in this photo I took in HNL. and you can see it in this photo I took of the MD-11 and use the hangar opening as a straight line. HTH  
Last WAL/DAL DC-10 out of HNL
Big version: Width: 2970 Height: 2076 File size: 429kb
812 in LAX


[Edited 2012-03-04 07:37:37]
 
Fabo
Posts: 1174
Joined: Tue Aug 16, 2005 1:30 am

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 8:33 pm

Very visible on 757-300.
 
Viscount724
Posts: 19316
Joined: Thu Oct 12, 2006 7:32 pm

RE: MD-11 "Bent" Fuselage In Flight?

Sun Mar 04, 2012 9:06 pm

I think what you're seeing is the way the upper fuselage begins to slope slightly downward starting slightly ahead of the rear door, as on the DC-10.
 
aviopic
Posts: 2423
Joined: Sat Mar 13, 2004 7:52 pm

RE: MD-11 "Bent" Fuselage In Flight?

Sat Mar 10, 2012 8:26 am

Quoting Northwest727 (Thread starter):
Am I just going out of my mind and seeing things, or is this actually the case?

I've no information about you and the state of your mind 
But the other two are both correct.
It's easy to play tricks on the human mind with photography(or with vision in general) as every photographer knows.
And a fuselage does distort as can be clearly seen in a photo I made years ago.


View Large View Medium
Click here for bigger photo!

Photo © Willem Honders

 
CosmicCruiser
Posts: 2521
Joined: Tue Feb 22, 2005 3:01 am

RE: MD-11 "Bent" Fuselage In Flight?

Sat Mar 10, 2012 10:53 am

Quoting Viscount724 (Reply 7):
I think what you're seeing is the way the upper fuselage begins to slope slightly downward starting slightly ahead of the rear door, as on the DC-10.

I agree
 
musang
Posts: 818
Joined: Sun Apr 08, 2001 4:11 am

RE: MD-11 "Bent" Fuselage In Flight?

Sat Mar 10, 2012 11:11 am

Interesting thread.

I think there are a couple of different phenomena being discussed here though. I think the original post referred to the belly of the MD-11. Later mention of the MD-11 / DC-10 upper rear fuselage below the no. 2 engine refers to a design feature, as n901wa says, which is one of the type's signature visual characteristics.

Personally, I don't see a "bent" fuselage belly profile on the 757, and suggest that what can be seen is the parallel but unaligned belly profile ahead and aft of the wing. The rear fuselage is a deeper cross-section that the forward i.e. behind the wing/fuselage fairings it doesn't return to the same depth as the fwd fuselage. The 727 is the same.

However, the 777-300 pics are interesting. Displaying them large and placing a ruler on the screen, there does seem to be a mis-alignment of the belly fwd vs. aft of the wing. It does appear bent. The area for scrutiny is near the centre of the frame in each of the 777-300 pics, taken with telephoto lenses, so there's minimal peripheral distortion, so brilliantly illustrated in aviopic's wide-angle Caravan image.

Other candidates for this phenomenon may include the A340-600 and DC-8-61/3/71/73 so I'd look for long focal length, side profile shots.

I once heard that large ships e.g. supertankers are built with a bent hull to take account of the curvature of the earth, and know that the towers of suspension bridges (e.g. Humber, Severn, Verrazano Narrows etc.) are out of parallel for the same reason. However I would not think this is a consideration in aircraft design!

Regards - musang
 
zanl188
Posts: 3864
Joined: Sat Oct 21, 2006 9:05 pm

RE: MD-11 "Bent" Fuselage In Flight?

Sat Mar 10, 2012 11:58 pm

We can't have a "Does the fuselage bend?" thread without the containership flexing video.

So without further ado....

http://www.youtube.com/watch?v=qEkErF51Uxg&feature=related
 
Flighty
Posts: 9963
Joined: Thu Apr 05, 2007 3:07 am

RE: MD-11 "Bent" Fuselage In Flight?

Mon Mar 12, 2012 1:15 am

A fisheye effect could also be doing this. You would have to true the image against a known straight object, unless image processing is smart enough to do this "holistically." Which I am not sure about, if we are talking about hundreths of a degree.
 
CosmicCruiser
Posts: 2521
Joined: Tue Feb 22, 2005 3:01 am

RE: MD-11 "Bent" Fuselage In Flight?

Mon Mar 12, 2012 2:31 am

no manual diagrams show nor text mention this.
 
Northwest727
Topic Author
Posts: 379
Joined: Sat Jul 30, 2005 10:38 am

RE: MD-11 "Bent" Fuselage In Flight?

Mon Mar 12, 2012 2:01 pm

Quoting aviopic (Reply 8):
I've no information about you and the state of your mind

Sometimes, I wonder about myself 

Who is online

Users browsing this forum: Fiver and 10 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos