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-   -   Shorten a big plane ,rather than stretch a smaller one (https://www.pprune.org/rumours-news/622575-shorten-big-plane-rather-than-stretch-smaller-one.html)

fitliker 17th Jun 2019 00:08

Shorten a big plane ,rather than stretch a smaller one
 
Has anyone successfully shortened a big aircraft to make a smaller one ?
Rather than stretch the 737 ,which already a stretched 707 , why did they not cut twenty feet of the front and twenty feet off the back of a 757 ?
A shortened 757 might work better than an over stretched 707.

Anilv 17th Jun 2019 01:02

i believe the wings are design for a specific mission, ie what works for a 757 for flights more than 3 hours will not be as effecient as a wing designed specifically for shorter flights. Also the bigger engines on the 757 would cost more, the landing gears also as they are tall to enable the engine clearance.

Shortening aircraft has been done before.
The 747 was shortened which resulted in the 747-SP.
The A320 was shortened to produced the A319/318
The 707 was shortened and became the 720

Anilv

stilton 17th Jun 2019 01:13

Boeing proposed a shorter 757-100 but there were no takers, the seat costs were far better to go with the standard-200 model


Furthermore a shorter version of the -200 would be ‘overbuilt’ and heavier than optimal as the structure was optimized for a larger aircraft


Always more economical to stretch than shrink

Bend alot 17th Jun 2019 01:57

The prototype B757 rolled out 37 years ago.

The B737 needs a new clean sheet replacement.

20% more fuel efficient than the NG should be realistic, a focus on passenger comfort a priority.

Lockable overhead bins and live data feeds standard.

Wizofoz 17th Jun 2019 02:11

The 737-500 and 600 where both shortened versions, and neither were very popular. Similarly, the F-70 was a shortened F-100.

The problem is shortening an aircraft usually results in an over-engineered aircraft, where as stretching one and doing whatever engineering is necessary to accommodate the stretch leave one just about right.

The 777-300ER is probably the best example of a successful "stretch".

Imagegear 17th Jun 2019 05:00


a focus on passenger comfort a priority,
Only in your dreams, if they could get away with it we would all be anesthetised, stacked on pallets and lashed down.

IG

ShyTorque 17th Jun 2019 05:07


Has anyone successfully shortened a big aircraft to make a smaller one ?
Try looking up the Boeing 747SP.

Remember watching that type in the Far East, climbing like no other.

DaveReidUK 17th Jun 2019 06:51


Originally Posted by Wizofoz (Post 10495373)
The 737-500 and 600 where both shortened versions, and neither were very popular.

That's an understatement, at least in the case of the -600. While Boeing sold almost 400 of the -500 series, only 69 -600s were ever built, almost half of those for a single airline (SAS).


Originally Posted by ShyTorque (Post 10495415)
Try looking up the Boeing 747SP.

Remember watching that type in the Far East, climbing like no other.

A great performer, but commercially it fared even worse than the short 737s - there's no way that selling 44 aircraft got anywhere close to covering the NRCs.

stilton 17th Jun 2019 10:42


Originally Posted by Bend alot (Post 10495370)
The prototype B757 rolled out 37 years ago.

The B737 needs a new clean sheet replacement.

20% more fuel efficient than the NG should be realistic, a focus on passenger comfort a priority.

Lockable overhead bins and live data feeds standard.



live data feeds sound like a good idea, locking the overhead bins in the hope this will speed evacuations, preventing passengers from taking their carry ons is not


In the heat of the moment, despite any and all PA announcements passengers will delay evacuation even further as they attempt to pry open the ‘inexplicably’ jammed bins and retrieve their duty free, etc, some will not give up until they’re found by the fire services later


It’s a well intended idea that will actually make things worse

The Bartender 17th Jun 2019 12:11

The only way you will stop pax from trying to evacuate with their luggage, is to remove the bins and put everything in the hold...

Bend alot 17th Jun 2019 12:22


Originally Posted by stilton (Post 10495667)




live data feeds sound like a good idea, locking the overhead bins in the hope this will speed evacuations, preventing passengers from taking their carry ons is not


In the heat of the moment, despite any and all PA announcements passengers will delay evacuation even further as they attempt to pry open the ‘inexplicably’ jammed bins and retrieve their duty free, etc, some will not give up until they’re found by the fire services later


It’s a well intended idea that will actually make things worse

Open lockers and close lockers only by cabin crew.

Soon all learn only cabin crew can open and close the bins - just like waiting for a meal or a drink - must wait and takes time.

Mac the Knife 17th Jun 2019 12:30

"........anesthetised, stacked on pallets and lashed down."

Which would be a great deal pleasanter than travelling cattle-class for long journeys these days....

Mac

krismiler 17th Jun 2019 13:08

Something designed from the start for a specific purpose will usually be better than adapting something else to fit. There is normally a bit of leeway with a design and some variation is feasible but there comes a point where a new design would be a better option. The DC8 Super 60s series was stretched to about the longest practical length possible for a narrow body and any further increase in passenger numbers needed to be accommodated through increased width rather than length. Had the A380 been a commercial success there was the possibility of increasing the length but there wasn't enough demand for an upgraded variant.

nonsense 17th Jun 2019 13:23


Originally Posted by Imagegear (Post 10495411)
Only in your dreams, if they could get away with it we would all be anesthetised, stacked on pallets and lashed down.

As an Australian, many hours from pretty much anywhere else, YES PLEASE!

WHBM 17th Jun 2019 13:27

There have actually been quite a number over time, some mentioned above. Most major manufacturers have done one or more shrinks. The A319 is probably the most successful of all, but the 737-500 also sold in good numbers. Both types had good secondhand value as well.

I think a BAC One-Eleven prototype was unique in being physically cut and lengthened to be the prototype series 500, and then the same airframe was again cut and shortened back to be the prototype series 475.

Lord Bracken 17th Jun 2019 13:40

The 777-300 / 300 ER are not really streches in the true sense of the word, the 777 programme from the design stage always planned two fuselage lengths and A, B and C 'market' ranges.
The A380-800 is actually a shrink, the wing is optimised for the longer fuselage -900 which never went into production.

Smythe 17th Jun 2019 13:58

In some respects, the 787-3 was shortened..at least the wingspan...

oldchina 17th Jun 2019 14:15

A330 sales were sluggish until the shrink A330-200 came along to kill off the 767

oggers 17th Jun 2019 14:31


Originally Posted by fitliker (Post 10495341)
Has anyone successfully shortened a big aircraft to make a smaller one ?
Rather than stretch the 737 ,which already a stretched 707 , why did they not cut twenty feet of the front and twenty feet off the back of a 757 ?
A shortened 757 might work better than an over stretched 707.

The 737 is not a stretched 707.

tdracer 17th Jun 2019 18:15

It's probably worth noting that the 737-500/600 are basically the same size as the 737-200 - which was technically a stretch of the 737-100 (granted not many of the -100 variant were built). What killed the 757 was that when the 737NG came along (particularly the -900 variant), it could do most of what the 757 could do and had better operating economics, only falling short on range. Further, the 737 was way cheaper to build than the 757
'Shrinking' an existing design seldom goes well - as noted the wing is too big and heavy and much of the rest of the structure is similarly sub-optimal. Off hand, I can only think of the A319 as a reasonably successful 'shrink', while the A318 was a major flop.


A great performer, but commercially it fared even worse than the short 737s - there's no way that selling 44 aircraft got anywhere close to covering the NRCs.
The 747SP filled a specific need for more range - trading payload for fuel. I don't think the SP was a financial failure - at least not a major one. The market and NRC structures were far different in those days so it was much cheaper to bring the SP to market than it would be today, and the margins that aircraft sold for were much larger.


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