LY777
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Why Don't 757s Have The Same Nose As 737/727/707s?

Sat Sep 15, 2012 8:54 pm

All Boeing narrowbodies (707/727/737) have the same nose, except the 757, why?

[Edited 2012-09-15 13:56:22]
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IMissPiedmont
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Sat Sep 15, 2012 8:58 pm

Boeing went with a common cockpit and type rating of the 757 and 767
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PHX787
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Sat Sep 15, 2012 9:20 pm

Quoting IMissPiedmont (Reply 1):
Boeing went with a common cockpit and type rating of the 757 and 767

Apparently as well, the 767 and the 777 share very similar cockpit components. (IIRC, isn't the 767 section 41 the same as the 777?)
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Viscount724
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Sat Sep 15, 2012 9:54 pm

Quoting PHX787 (Reply 2):
isn't the 767 section 41 the same as the 777?

According to Reply 16 in this 2010 thread, the only part of section 41 that's the same is the frame around the cockpit windows and the radome.
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BoeingGuy
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Sun Sep 16, 2012 6:58 pm

Quoting IMissPiedmont (Reply 1):
Boeing went with a common cockpit and type rating of the 757 and 767

That has nothing to do with the OP's question. The shape of the nose itself has no relation to whether the flight deck instruments are identical enough to achieve a common type rating.

Quoting PHX787 (Reply 2):
Apparently as well, the 767 and the 777 share very similar cockpit components.

The 767-400 and 777 have a few similarities in the flight deck (a relatively few actually) but again nothing to do with the OP's question.

To be honest I don't know the answer to the OP's real question but perhaps a long time Boeing person who worked on the 757 program can?
 
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Starlionblue
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Sun Sep 16, 2012 7:26 pm

Quoting BoeingGuy (Reply 4):
Quoting IMissPiedmont (Reply 1):
Boeing went with a common cockpit and type rating of the 757 and 767

That has nothing to do with the OP's question. The shape of the nose itself has no relation to whether the flight deck instruments are identical enough to achieve a common type rating.

If memory serves, the 757 had to have the cockpit seats at a certain height above the ground to share the rating with the 767. And that's why the 757 nose shape has a lot to do with the type rating.
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OldAeroGuy
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Sun Sep 16, 2012 8:15 pm

Quoting BoeingGuy (Reply 4):
Quoting IMissPiedmont (Reply 1):Boeing went with a common cockpit and type rating of the 757 and 767
That has nothing to do with the OP's question. The shape of the nose itself has no relation to whether the flight deck instruments are identical enough to achieve a common type rating.

Actually. the shape of the 757 nose was dictated by the 767 flight deck arrangement. The 757 nose had to widened and the flight deck floor had to be slanted down to accommodate the 767 flight deck displays. In addition, the flight deck floor had to be lowered, so you step down to enter the 757 flight deck, but step up to enter on the 767's.

The distinct 757 nose was created by these modifications.

Quoting Starlionblue (Reply 5):
If memory serves, the 757 had to have the cockpit seats at a certain height above the ground to share the rating with the 767. And that's why the 757 nose shape has a lot to do with the type rating.

The ground height was not important, but forward view was. The 757 and 767 have a similar forward view on approach. This is another reason why the 757 flight deck floor slopes down.
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tdscanuck
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Mon Sep 17, 2012 12:15 am

Quoting BoeingGuy (Reply 4):
Quoting IMissPiedmont (Reply 1):
Boeing went with a common cockpit and type rating of the 757 and 767

That has nothing to do with the OP's question. The shape of the nose itself has no relation to whether the flight deck instruments are identical enough to achieve a common type rating.

It's not just about instruments. The view has to be comparable; there was just no way to get the same visual field in a 737-style cockpit to be close enough to the 767 for common rating.

Tom.
 
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bikerthai
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Tue Sep 18, 2012 6:38 pm

Quoting OldAeroGuy (Reply 6):
The 757 nose had to widened and the flight deck floor had to be slanted down to accommodate the 767 flight deck displays. In addition, the flight deck floor had to be lowered, so you step down to enter the 757 flight deck, but step up to enter on the 767's.

The distinct 757 nose was created by these modifications.

So is the following statement an urban myth:

The nose of the 757and 767 are also structurally the same for production purposes? I thought I heard somewhere that from cockpit window forward, the 767 and 757 have the same nose shape.

bt
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HaveBlue
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Tue Sep 18, 2012 6:59 pm

Quoting OldAeroGuy (Reply 6):
Actually. the shape of the 757 nose was dictated by the 767 flight deck arrangement. The 757 nose had to widened and the flight deck floor had to be slanted down to accommodate the 767 flight deck displays. In addition, the flight deck floor had to be lowered, so you step down to enter the 757 flight deck, but step up to enter on the 767's.

The distinct 757 nose was created by these modifications.

Very interesting, never ever heard of that. And that's why I love these forums!
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DocLightning
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Tue Sep 18, 2012 10:23 pm

Quoting bikerthai (Reply 8):
The nose of the 757and 767 are also structurally the same for production purposes? I thought I heard somewhere that from cockpit window forward, the 767 and 757 have the same nose shape.

No, that is absolutely false. One need only look at both aircraft to see that it's not true. The parts of the nose visible from the cockpit need to be the same shape, yes, but the entire nose is markedly different.

As for the 707, 727, and 737, recall that Boeing decided to use the same nose for all three to simplify design and construction. Pilots really don't like the 737 nose and there are issues with visibility and ergonomics. When it came time to design the 757, Boeing designed an entirely new narrowbody nose for the reasons outlined in this thread.

It turned out that the 737 would outlive the 757 (something I don't think Boeing forsaw at the time). Boeing can't change the nose of the 737 to match the 757 (although it would make pilots happier) because it would basically make the aircraft into an entire new type and mean that pilots would not be able to move from the 737-classics to the 73G/73MAX series.

You will notice that the A320 and the DC-9 series have similar noses with a "droopy" profile, much like the 757. I am given to understand that pilots like that sort of profile a lot more.
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Viscount724
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Wed Sep 19, 2012 1:39 am

Quoting DocLightning (Reply 10):
As for the 707, 727, and 737, recall that Boeing decided to use the same nose for all three to simplify design and construction.

The forward fuselage section of the 707 is not identical to the 727 and 737, and I don't even think the 727 and 737 sections are completely identical. The 707 in particular has a deeper fuselage from top to bottom than the 727/737.
 
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bikerthai
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Wed Sep 19, 2012 1:18 pm

Quoting DocLightning (Reply 10):

No, that is absolutely false.

As with most urban myth, there is a sliver of truth.

I found this"

http://seattletimes.com/news/business/757/part03/

"And hanging on Condit's office wall, framed and signed, is one of White's original renderings of how he thought the 767 cab could be fitted to the 757. "

I guess this is where it started. The article is an interesting read.

bt
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kanban
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Wed Sep 19, 2012 3:56 pm

actually they got tired of A.netters complaining about 50 year old designs...      
 
AAR90
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Wed Sep 19, 2012 5:42 pm

Quoting LY777 (Thread starter):
All Boeing narrowbodies (707/727/737) have the same nose, except the 757, why?

707 is late 1950's design.
727/737 are early 1960's designs.
757 is late 1970's design.

The 727 & 737 followed the original 707 fairly quickly (in time) so their designs were essentially modifications to the original 707 aircraft. There was a significant gap in time before the 757 was developed and there was significant improvement in aerodynamics (and other areas) during that time.

Different era = different designs.
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HAWK21M
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Thu Sep 20, 2012 6:31 am

Cockpit commonality between the B757 AND B767 determined this.

Quoting DocLightning (Reply 10):
It turned out that the 737 would outlive the 757 (something I don't think Boeing forsaw at the time).

Agreed.....
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PurdueAv2003
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Thu Sep 20, 2012 7:44 am

Quoting Viscount724 (Reply 11):
It turned out that the 737 would outlive the 757 (something I don't think Boeing forsaw at the time). Boeing can't change the nose of the 737 to match the 757 (although it would make pilots happier) because it would basically make the aircraft into an entire new type and mean that pilots would not be able to move from the 737-classics to the 73G/73MAX series.

I don't think the new cockpit would have changed the type. Look at the changes in wing and pylon structure between the classics and NG. In fact, I had heard a rumor once that Boeing had originally considered the 757 Forward Nose section for the NG, but someone at WN didn't like the look of the design, so they reverted back to the older design.
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tdscanuck
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Thu Sep 20, 2012 4:18 pm

Quoting PurdueAv2003 (Reply 16):
I don't think the new cockpit would have changed the type. Look at the changes in wing and pylon structure between the classics and NG.

The wing/pylon structure doesn't have any impact on crew commonality...the flight deck design has huge impacts. For the same reasons that the 757 and 767 needed very similar flight decks to have a common crew rating, the 737 can't change noses.

Tom.
 
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DocLightning
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RE: Why Don't 757s Have The Same Nose As 737/727/707s?

Thu Sep 20, 2012 5:33 pm

Quoting PurdueAv2003 (Reply 16):
I don't think the new cockpit would have changed the type. Look at the changes in wing and pylon structure between the classics and NG. In fact, I had heard a rumor once that Boeing had originally considered the 757 Forward Nose section for the NG, but someone at WN didn't like the look of the design, so they reverted back to the older design.

Not at all. As TDSCanuck says, a change in the cockpit changes the type rating for the crew. WN cares not one whit about the look. They care that every single last pilot on their payroll can fly every single last plane in their fleet.
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