PC12Fan
Topic Author
Posts: 1967
Joined: Sat Jan 27, 2007 11:50 pm

Restarting A Production Line 101 Question.

Tue Jul 10, 2012 5:58 pm

OK, we've all seen those "should Boeing reintroduce the 757?" type threads to the point of nausa - which in philosophy I agreed with BTW, but that's another thread.  

At any rate, my question is how difficult would it be to replace the "tooling" needed for the construction of these aircraft? I mean, the tooling was built once before. Surely there are records somewhere where the plans could be accessed. It's been done already, you know? That should reduce the production costs somewhat since it doesn't have to be designed from scratch.

Again, production 101 question so I'm just looking at this from someone that really has no idea about this particular process. Thanks.
Just when I think you've said the stupidest thing ever, you keep talkin'!
 
roseflyer
Posts: 9606
Joined: Fri Feb 13, 2004 9:34 am

RE: Restarting A Production Line 101 Question.

Tue Jul 10, 2012 6:15 pm

Quoting PC12Fan (Thread starter):

At any rate, my question is how difficult would it be to replace the "tooling" needed for the construction of these aircraft? I mean, the tooling was built once before. Surely there are records somewhere where the plans could be accessed. It's been done already, you know? That should reduce the production costs somewhat since it doesn't have to be designed from scratch.

Tooling isn’t where the significant cost would likely be. There is significant infrastructure cost involved, but also an obsolete design that would need to be brought up to standard. There is no where to manufacture the 757 fuselage any more. The building where it was made is now a shopping mall, so it would have to be created from scratch. I’m guessing that Spirit in Wichita could probably be contracted to do it, or it could be done in house by Boeing again. As far as wing production goes, again there is no wing laydown, but there is wing laydown for the 737NG in Renton, and it is possible that they could find a way to make the infrastructure work. Again there’s no final assembly location, but that’s something that can be overcome.

The bigger problem is that the supply chain is gone for the airplane which consisted of thousands of suppliers around the world. Spares production is virtually nonexistent, so there’s no supplier network to make all the parts. Furthermore the designs are obsolete and stagnant. Therefore they would have to be brought up to current standards. Many of the old suppliers likely wouldn't even want to build parts again or would charge extremely high prices. I doubt the FAA would grant a waiver to resume production after 10 years without having to requalify the designs and parts to some degree. That is massive cost, and at that point you might as well start over. Restarting the 757 production line would likely take more engineering work than the entire 747-8 program did and that would be if they kept the 757 as is and didn’t even try to improve it.

There have been many people saying it was a bad decision that the tooling and infrastructure was scuttled, but in reality the design is dead and the FAA is not going to allow parts to be re-used without meeting current requirements. With no supply chain in place, obsolete designs, and no infrastructure, the 757 design is about worthless unless some third tier manufacture wanted to copy some it and create a subpar airplane as a science project (like what COMAC did with the ARJ21).

[Edited 2012-07-10 11:17:21]
If you have never designed an airplane part before, let the real designers do the work!
 
smittyone
Posts: 1336
Joined: Thu Feb 09, 2012 12:55 am

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 1:46 pm

Quoting Roseflyer (Reply 1):
Spares production is virtually nonexistent

Not that I disagree with the unfeasbility of restarting a production line, but is this statement really true? I mean I was thinking that there must be a fairly robust market to produce the most commonly replaced parts for an aircraft that has almost 1000 airframes still in (heavy) service.

Also, does 'parts availability' factor into whether an aircraft type retains its FAA or other certification?
 
rfields5421
Posts: 5543
Joined: Thu Jul 19, 2007 12:45 am

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 2:02 pm

Quoting SmittyOne (Reply 2):
there must be a fairly robust market to produce the most commonly replaced parts

Certainly.

However, it is the thousands of almost never replaced parts that are the problem for the supply chain.
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 3:04 pm

Quoting SmittyOne (Reply 2):
Not that I disagree with the unfeasbility of restarting a production line, but is this statement really true? I mean I was thinking that there must be a fairly robust market to produce the most commonly replaced parts for an aircraft that has almost 1000 airframes still in (heavy) service.

Line Replaceable Units will still be in some state of low-rate production. But things you can't really replace, or almost never replace, are likely stopped. Most components have a Component Maintenance Manual and can be rebuilt or repaired; the majority of spare parts (that aren't consumables like seals) are overhauled, not new.

Quoting SmittyOne (Reply 2):
Also, does 'parts availability' factor into whether an aircraft type retains its FAA or other certification?

Spares availability should have nothing to do with type certification; the type certificate is against a design, not a particular aircraft. It just says "If you have this design, it complies with the FARs". It says nothing about how you get the design.

Spares availability is most likely to come into play with the airworthiness certificate and operating certificiate. If you don't have spares and you fall out of type design, that aircraft's airworthiness certificate isn't valid. If you can't maintain a type, then you won't be allowed to add that type to your operating certificate.

Tom.
 
User avatar
kanban
Posts: 3642
Joined: Sun Jan 06, 2008 1:00 am

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 4:16 pm

Quoting Roseflyer (Reply 1):
Spares production is virtually nonexistent


Having spent years in the Boeing Spares system, 757 spares are stocked both at Boeing and at suppliers, plus Boeing has suppliers that will build anything not available. the biggest problems are the lead times, spares planners look at lead-times and sales rates to pre order parts (landing gear components typically require three years so processes are set up with the supplier to partially machine to the broadest configuration and hold further finishing until needed.). Items like flaps, rudders, etc have a exchange process where the airline can lease a replacement while their unit is being repaired.. the leased unit is the zero timed when returned. incidentally all manufacturing plans are still available.

But back to the question of restarting.. first a new wing/fuselage and FAL assembly site must be located and built, second Boeing would not just throw the old a/p back into production without updating and adding items necessary for a competitive edge (a 757MAX if you will). That could mean redesign of tooling. Then comes long lead procurement of wing line tooling. the development of a supplier base can take 3 years... Then there is the economics .. If we start the idea today, in 2 years we'll have product definition to take to the airlines that would deliver 5 years later.. so will the product be competitive in 7 years? are there enough customers to warrant the cost? Now some may argue with my time line.. compared to a revamp of something in production it takes longer. and yes common supplier items with the767 and tanker line would shorten it a bit.
 
smittyone
Posts: 1336
Joined: Thu Feb 09, 2012 12:55 am

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 4:53 pm

Thanks Men, that is really good info.

Quoting kanban (Reply 5):
Boeing would not just throw the old a/p back into production without updating and adding items necessary for a competitive edge (a 757MAX if you will

Does seem like it would be more profitable to just design a new aircraft if you'd be redoing the engines and the wings at the very least anyway!

How sweet would a 757-sized '787' be!?
 
canoecarrier
Posts: 2569
Joined: Sat Feb 14, 2004 1:20 pm

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 5:11 pm

Quoting Roseflyer (Reply 1):
There is no where to manufacture the 757 fuselage any more. The building where it was made is now a shopping mall, so it would have to be created from scratch.

I assume you're talking about the area that has that apartment/condo development and the Target store south of the plant? The Seattle Times just ran an article about how the 737 line in Renton is land starved and facing some challenges to get more production out of the existing plant after Boeing sold off "excess land" 10 years ago.

http://seattletimes.nwsource.com/htm...echnology/2018604845_boeing05.html

As an aside, what happens to the tooling once they close down a production line? I'd assume some of the tools can be used on other aircraft, but others may be specific to that aircraft type? Are they destroyed or sold off to suppliers?
The beatings will continue until morale improves
 
User avatar
kanban
Posts: 3642
Joined: Sun Jan 06, 2008 1:00 am

RE: Restarting A Production Line 101 Question.

Thu Jul 12, 2012 9:36 pm

Quoting canoecarrier (Reply 7):
what happens to the tooling once they close down a production line?


some are stored if used to make spares or for aircraft repairs, although the repair guys have their own and can rebuild most structure without tooling ... most assembly jigs and join tools are transported off site, cut up and sold for scrap.
 
planemaker
Posts: 5411
Joined: Mon Aug 25, 2003 12:53 pm

RE: Restarting A Production Line 101 Question.

Sat Jul 14, 2012 6:43 am

Of course, a completely different kettle of fish but interesting in that it is the only commercial aircraft program that I can think of that has been re-started is the Twin Otter. The DH program was shut down by Boeing in 1988 and was re-started in 2007 by Viking (Viking acquired all the the legacy DH type certificates from BBD.)

http://upload.wikimedia.org/wikipedia/commons/6/61/First_Flight_Twin_Otter_Series_400_C-FDHT.jpg
Nationalism is an infantile disease. It is the measles of mankind. - A. Einstein
 
User avatar
lightsaber
Crew
Posts: 11728
Joined: Wed Jan 19, 2005 10:55 pm

RE: Restarting A Production Line 101 Question.

Sat Jul 14, 2012 10:20 pm

Quoting planemaker (Reply 9):
the only commercial aircraft program that I can think of that has been re-started is the Twin Otter.

As an enthusiast, I hope one day the DC-3 too:
http://en.wikipedia.org/wiki/Basler_BT-67

Quoting PC12Fan (Thread starter):
how difficult would it be to replace the "tooling" needed for the construction of these aircraft? I mean, the tooling was built once before. Surely there are records somewhere where the plans could be accessed. It's been done already, you know? That should reduce the production costs somewhat since it doesn't have to be designed from scratch.

That depends on the technology of the aircraft. The simpler the design, the cheaper it is. In particular is newer alloys are superior substitutes (crack propagation, yield tensile strength, corrosion resistance, and hardness).

Quoting rfields5421 (Reply 3):
However, it is the thousands of almost never replaced parts that are the problem for the supply chain.

   But for the 757, they should be producible.

To others:
However, why would one? The 757 is heavy and has a high maintenance burden versus the 737/A320. Now much of the 737's lower maintenance burden is due to customer demand for improvements to cut the maintenance bill. Due to the high sales, Boeing has continually improved the subsystems. That is not so with the 757.

There is no cheap way to make the 757 competitive on missions under 3,000nm vs. the 737-9 (MAX) or the A321NEO. The 757 simply has too much weight and maintenance burden to be competitive.

IMHO, we'll see a TATL MAX or NEO soon too. Once that happens, the last 757 market is gone.
It will take a new airframe to be competitive.

Lightsaber
"They did not know it was impossible, so they did it!" - Mark Twain
 
Aircellist
Posts: 1241
Joined: Fri Oct 08, 2004 8:43 am

RE: Restarting A Production Line 101 Question.

Mon Jul 23, 2012 11:11 pm

Quoting kanban (Reply 5):
landing gear components typically require three years

If I'm not wandering too far out of topic, how come it is that long?
"When I find out I was wrong, I change my mind. What do you do?" -attributed to John Maynard Keynes
 
zanl188
Posts: 3434
Joined: Sat Oct 21, 2006 9:05 pm

RE: Restarting A Production Line 101 Question.

Tue Jul 24, 2012 12:28 am

Quoting planemaker (Reply 9):
Of course, a completely different kettle of fish but interesting in that it is the only commercial aircraft program that I can think of that has been re-started is the Twin Otter

Romanian 111 production comes to mind.
Legal considerations provided by: Dewey, Cheatum, and Howe
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: Restarting A Production Line 101 Question.

Tue Jul 24, 2012 12:37 am

Quoting Aircellist (Reply 11):
Quoting kanban (Reply 5):
landing gear components typically require three years

If I'm not wandering too far out of topic, how come it is that long?

It's the forgings that do it.

Landing gear main struts are forged from incredibly high spec exotic steel. The steel mills don't run it very often and, when they do, there are only a few forges in the world capable of doing the forging and they like to work in batches. As a result, they have to start waaaaay before the gear is actually due because they have essentially zero capability to expedite if they get behind. Then you have a huge machining job (which takes a long time because the material is so strong) followed by an incredibly exhaustive NDI regimen...and that's just to get the strut ready for the rest of the gear to be assembled onto it.

Tom.
 
Aircellist
Posts: 1241
Joined: Fri Oct 08, 2004 8:43 am

RE: Restarting A Production Line 101 Question.

Tue Jul 24, 2012 7:39 pm

Quoting tdscanuck (Reply 13):
It's the forgings that do it.

Thank you very much.

So, part of the delay would be for the availability of the forge, part for the availability of the raw material and part for the task itself, plus, finally, some kind of contingency just in case... How much of each, again if I may ask ?

... I'm pretty curious... because I somehow compare it with the length of time it takes my violinmaker to make a double-bass... which has come down from about a year, for the first he made, to about six or seven months, for the most recent ones. Carving (mostly), scuplting, heat forming, gluing, varnishing...
"When I find out I was wrong, I change my mind. What do you do?" -attributed to John Maynard Keynes
 
roseflyer
Posts: 9606
Joined: Fri Feb 13, 2004 9:34 am

RE: Restarting A Production Line 101 Question.

Tue Jul 24, 2012 7:45 pm

Quoting Aircellist (Reply 14):


So, part of the delay would be for the availability of the forge, part for the availability of the raw material and part for the task itself, plus, finally, some kind of contingency just in case... How much of each, again if I may ask ?

As a side note, there is a shortage of landing gear for 777s and 737NGs as well. Boeing has increased production rates, but that has limited the number of landing gear available for overhaul. Landing gear overhaul is an expensive and time consuming process that takes place every 10 years or so. Airlines have to schedule their landing gear overhaul 2 years in advance in order to ensure they will have refurbished gear to put on their airplane when they send the existing gear for overhaul.
If you have never designed an airplane part before, let the real designers do the work!
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: Restarting A Production Line 101 Question.

Tue Jul 24, 2012 7:49 pm

Quoting Aircellist (Reply 14):
So, part of the delay would be for the availability of the forge, part for the availability of the raw material and part for the task itself, plus, finally, some kind of contingency just in case... How much of each, again if I may ask ?

The figure of ~3 years gets tossed around within the industry fairly often but I don't know what the breakdown there is between the raw material melt, the forge, the actual finishing, and the contingency. I would guess the forge is the longest lead but that's just a guess.

Tom.
 
dynamicsguy
Posts: 442
Joined: Tue Jul 08, 2008 9:24 am

RE: Restarting A Production Line 101 Question.

Wed Jul 25, 2012 7:55 am

Quoting planemaker (Reply 9):
Of course, a completely different kettle of fish but interesting in that it is the only commercial aircraft program that I can think of that has been re-started is the Twin Otter.

Another bush plane being revived is the Government Aircraft Factory N24 Nomad which is due to restart production as the Gipps Aero GA18.

Who is online

Users browsing this forum: jonchan627 and 11 guests