trouble 't mill?

[Thirty Eight South]

4 weeks and counting, can't remember where the pictures come from, but they show 787 barrel sections 41/5-19 mis-match, a recognized problem with this manufacturing method borrowed from the MV-22 fuselage manufacture method
BusinessWeek has learned that Boeing's engineers are wrestling with several significant technical and production problems that could threaten the scheduled 2008 delivery of the jetliner
At a time when Boeing has left itself with little margin for error, the wide-ranging series of glitches could create a domino effect if they aren't resolved quickly. The worst news: The fuselage section -- the big multi-part cylindrical barrel that encompasses the passenger seating area -- has failed in company testing. That's forcing Boeing to make more sections than planned, and to reexamine quality and safety concerns.
http://www.businessweek.com/magazine/content/06_25/b3989049.htm

+ Systems not installed.
+ Workmanship issues with the horizontal stabilizer.
+ Temporary fasteners that will have to be replaced.


Those are only some of what 787 workers at The Boeing Co.'s Everett plant face as the mad dash begins to get the first Dreamliner assembled and out the factory door by July 8.



http://i200.photobucket.com/albums/aa164/38south_photo/B1.jpg

http://i200.photobucket.com/albums/aa164/38south_photo/B2.jpg

http://i200.photobucket.com/albums/aa164/38south_photo/B3.jpg

[Dan Winterland]

I suspect there aren't too many people in Seattle laiughing about Airbus' misfortunes with the A380 right now.

[lomapaseo]

Typical pre-production problems and probably far easier addressed (with a large hammer) than rerouting a gazzillion miles of wires.

[Sallyann1234]

Are Boeing still designing a new airplane in the 21st century in INCHES?

[A Very Civil Pilot]

What's wrong with inches?
What about the (albeit 20th century space shuttle being in measures of roman chariots?
(Link to well-worn internet story!) http://www.seiyaku.com/reference/shuttle.html

[Sallyann1234]

Yes that's an interesting quote, but doesn't really justify the design of a new aircraft in an obsolete measurement system (if that really is the case?).
Try this link instead:
http://mars.jpl.nasa.gov/msp98/news/mco990930.html

[skiingman]

What's wrong with inches?

You must be that bald curmudgeon engineering prof who slapped me around with customary units I'd never heard of before but apparently are awful important to bald old people. Rankine what?

[Spodman]

...doesn't really justify the design of a new aircraft in an obsolete measurement system...Look a bit more closely, you'll see the ruler is metric, metric inches that is...

[Marvo]

They should have used Withworth.... I have several withworth spanners in my loft going spare..

[Max Angle]

far easier addressed (with a large hammer)Rather hard to address anything made in carbon fibre with a hammer I would have thought

[wobble2plank]

Can't they just heat it up with the missus's hairdryer and smudge it into shape with an engineers thumb :confused:

Thats what my lad does with his (late) airfix models ;)

Sheesh, all those engineering degrees outthought by a six year old :p

[james ozzie]

We should remember the Gimley Glider was partly caused by a SNAFU with non SI units

[Sallyann1234]

Isn't it time that aviation finally bit the bullet and standardised on SI units? How can such a safety-conscious industry continue to live with so many superfluous calculations and so many proven causes of error?
Sorry, I realise this is serious topic drift.

[john_tullamarine]

Isn't it time that aviation finally bit the bullet and standardised on SI units?

Some of us might even opine that the sorry mess could best be corrected by going back to slugs and poundals ..... real units with some meat to them ...

[forget]

With you 100% there JT. See what Bony had to say about 'metrication'. :ok:

http://i21.photobucket.com/albums/b270/cumpas/nap.jpg

[hetfield]

Yeah, let's have the rest of the world pennies and pounds, lefthand driving, fish and chips and a queen.....

[forget]

Location Sydney? You've already got three out of four.:)

[hetfield]

Yeah, the $ must be an accident:O, don't know 'cause not very good in history:*

[Sallyann1234]

Some of us might even opine that the sorry mess could best be corrected by going back to slugs and poundals ..... real units with some meat to them ...

It's relatively unimportant which standard is used. The key thing is that everyone uses the same one.
Since almost every country has adopted SI units, and the great majority of the world's population are taught in them, surely it is time that a great international industry fell into line. Not for the sake of appearance, but because of the undoubted benefits of efficiency and safety that will follow.
My original question is still unanswered - is the 787 really being designed in inches?

[Mad (Flt) Scientist]

If it is, its probably safer that way.
There's no especial risk in any given system of units; it's mixing systems that causes issues. Which would be riskier - sticking to inches and 'thou' on the Seattle production line, or having a switchover to millimetres - likely on just one programme at that.
"Gee, what's the standard tolerance, 10 (thou) mil?". NASA's inadvertent collision with Mars wasn't because of using metric or imperial - it was using BOTH that caused it. Sticking to what you know is often a good idea.

[The Bartender]

Sticking to what you know is often a good idea.

Agreed, but are all the subcontractors in this "international build-off" used to building in imperial units? :hmm:

[john_tullamarine]

it's mixing systems that causes issues

Aye .. the laddie speaks the truth ... I guess all engineers agonised for a term or so during their first undergraduate year coming to grips with 438,972 different systems of units of measure ..

.. mind you ... I was about 35 before I encountered the cheval (and had not the slightest idea what it was) .. I still am greatly confused as to why it isn't closer to the HP (at least, for those for whom size is important .. the English HP is bigger than the French) and as to 75kg.m/s, well that just about confuses me beyond comprehension ....

... then again, the Canadian French use CV for the English, rather than the French HP ... I think now .. I should just admit defeat ... give up and go to bed ..

The key thing is that everyone uses the same one.

Of course that is the answer to MFS' concern ... apologies if my imperfect attempt at humour caused me to be taken seriously .... I am rarely serious ..

are all the subcontractors in this "international build-off" used to building in imperial units

.. ah .. therein lies the empire whose name is QA ...

[james ozzie]

In Australia they regularly sell land in "perches" and size houses in "squares" - the salesperson could not tell me what a "square" was - well it is 100 square feet. Cannot recall what a perch is.

Feels a bit Dickensian.

And next, the cubic fortnight....???

[Mad (Flt) Scientist]

As a linear measure, a perch (also rod, or pole) is 1/4 of a chain, which is 22 yards (cricket pitch length). A perch is therefore 22/4=5.5 yards or 16.5 feet.

As an acre is an area one chain by one furlong, I'd take a guess that as a unit of land, a perch might be 1/4 of an acre i.e. 1 perch by one furlong.

edit: just wikipediaed it, and a perch as a unit of area actually an area one rod by one rod (or indeed, one perch by one perch) so there are 160 perches to the acre. Another useful fact learned. I think we'll use perches for our next wing area non-dimensionalisation.

[skiingman]

Metric fasteners in the US cost significantly more than their inch sized counterparts. Same materials, the tooling exists, the price is higher.

I've not found an anti-roll bar on any car from Europe, NA, or Asia that is manufactured to a metric size. Yet all of them specify the size in millimeters...gotta love the 25.4 millimeter bar.

I guess all engineers agonised for a term or so during their first undergraduate year coming to grips with 438,972 different systems of units of measure

Past first year, still find it outrageous and annoying.

The PS/SAE HP/DIN HP/CV/whatever stuff is not my idea of fun. Oddly enough, I haven't yet found the watt that isn't a watt. Am I not looking hard enough?

This idea that the units don't matter so long as the system is consistently applied also seems a bit weak to me. It is very easy for me to remember how the watt is defined. Its easy for me to relate it to units like the volt and ampere. It is considerably less easy and less accurate for me to do such mental gymnastics with whatever system of units. It would appear to me that the SI system and the technical units related to it are just plain better than the alternatives.

In any case, even if one doesn't care to admit that one system is inherently better than another, surely its obvious that multiple systems in use will cost lots of cash and time in order to avoid safety and quality problems.

[john_tullamarine]

Some thoughts ..

(a) all nonsense aside, life would be very much easier, and the system much safer, if we had ONE set of consistent, easily defined/derived units .. even if that would defeat the joys of in-house jargon etc ... and, of course, it doesn't matter an iota what ethnic origins such a system might have ...

(b) with mixed units, the PE folk are reasonably well off .. having been tortured in the initial undergraduate environment we all are quite comfortable with a rigorous application of units and unit to unit conversions ... however, for everyone else in the Industry, it is a recipe for disaster .. as shown by several well publicised events .. Gimli, for one.


Thread creep ... I've totally forgotten what the thread topic was ... a most wonderful aspect to PPRuNe is thread diversion and thread creep ... one picks up some gems of information along the way ...

[Bolty McBolt]

Metric V Imperial
I have a memory of a Mars landing craft that hit the mars surface at mach 3 because 1 part of the team were working in meters and the other feet and the calculations didn't mix :ok:

here is the link http://en.wikipedia.org/wiki/Mars_Climate_Orbiter

[MikeAlphaTangoTango]

Sorry for bringing the thread backto Earth with a bump but I'd love to know how Boeing are going to fix that little feature! Is it a hoax? Or have they got another one in build nearing completion?

[deeceethree]

Getting back to the main subject of this thread, this quote appears to come from someone close to the project, and can be found at this link, under the COMMENTS section:

http://www.thedigitalaviator.com/blog/?p=402

"I’ve heard the misalignment was caused by one of the fixtures used to hold the section, and not by the section itself, apparently it was causing a distortion and thereby the misalignment. Adjustments to the fixture resolved the problem and everything lined up. I believe the other problem is a fastener shortage and they have people running around like mad devils rounding up alternate suppliers. As you stated problems crop up as they progress, but nothing of a major concern. I have my invitation along with thousands of others, so I would assume the roll out on 7/8/7 will proceed as planned."

Seems to be sorted!

[bvcu]

There was a link to a 'seattle times' article on flights website a few days ago in an article ref using the KC767 for the rollout rehearsal. In the article there was a lot more info , also a very serious witch hunt to find the employee who had posted the pics !!!!

[ARINC]

AWG and AF both alive and well on the A380

[Choxolate]

On the subject of units - I am a PPL but like to keep a "watching" brief on the commercial forums (fora?).

Is it just history that the units in aviation are such a mix? as examples:
Altimeter settings in hectopascals (aka millibars) or inches of Hg
Altitude (in most place) in feet
Runway lengths in feet or metres
Distances in nautical miles

On light aircraft I have flown I have come acoss the following mixes of units :-
Fuel capacity in US gallons, litres, imperial gallons, kilos or pounds
Weight & balance in lbs and inch pounds, kilos and kilo cms
Air speeds in Knots, mph or Km/hour
Tyre pressures in lb/sq in or bar
Oil capacities in litres, US quarts, imperial pints
Boost in inches (of Hg?)

I know that a lot of these are "inherited" from the country of manufacture of the aircraft , but for safety and ease of use I have always been surprised that there is no standardisation.

It is just too easy to cock up a weight & balance calculation because of mixed units.

[john_tullamarine]

as examples:

.. ah ... music to an old engineer's ears ..... just like grandma's kitchen recipes .. a bit of this ... a bit of that ...

I guess that, eventually, we will find ourselves driven to a sensible metric system for all the sensible reasons which accrue ...

[411A]

I know that a lot of these are "inherited" from the country of manufacture of the aircraft , but for safety and ease of use I have always been surprised that there is no standardisation.

Why are they different, Choxolate?

Envy...and as a result, others have to be different.

Why envy?

Simply because, where aviation (in general) is concerned, the USA (and not to forget the UK in many areas) have more or less dominated the world for many many years in design and manufacture of aircraft, and others, are just so darn pi**ed off about this, that they just have to be 'different'.
Especially the 'metric' crowd, and those that follow it.:rolleyes:

The 'mass' (instead of 'weight') folks, or 'inches/feet is outdated' crowd will never be satisfied, and that is truly their collective problem...pure unadulterated envy, and their burden.

I really do have to laugh about this whole affair.

[Choxolate]

Blame the French - it usually works !! :ok:

[The Bartender]

Especially the 'metric' crowd, and those that follow it.:rolleyes:

That would be pretty much everyone, except USA, Burma, Liberia, and a few others, according to Wikipedia... :hmm:

[PIGDOG]

Hence forth, all references to speed, be it in relation to aviation or not, should be made in furlongs per fortnight (fpf).

http://en.wikipedia.org/wiki/Fortnight

and also

http://en.wikipedia.org/wiki/List_of_unusual_units_of_measurement

for a bit of a laugh.

[Sallyann1234]

I have my invitation along with thousands of others, so I would assume the roll out on 7/8/7 will proceed as planned.

And while we're on the subject of multiple standards, will you be attending on 7th August or 8th July?

[forget]

And while we're on the subject of multiple standards, will you be attending on 7th August or 8th July?

That is very very good! I like. :D:D

[N1 Vibes]

Again - getting back to the thread.....

So Boeing says it's the tooling eh? What is it they say about a 'bad' engineer always blaming his tools? :}

[Grunf]

N1,
'someone" said it was tooling. Fact is it was not.

Problem was resolved long time ago the usual way (gap within predicted limits). Don't you people think this was expected? If you have a barrel of that size it is EXPECTED to have gaps. Nothing unusual, nothing unpredicted.

Still going well, wait a little bit more and you'll see it.

Cheers

[Trash Hauler]

In this day and age of precision engineering that kind of gap would not be expected. Somewhere along the process a human SNAFU has occurred and sure as eggs the human is probably looking for a new job.

In the mean time Boeing (as was Airbus) are busy preserving their reputation.

TH

[ornithopter]

So we want to measure energy - how shall we do it?

We could use the English system and choose one of about a hundred measures including British Thermal Units, Foot Pound Force, Horsepower per hour etc of which there is an arbitary conversion to the others somewhere....now where did I put it again?

Or we could use SI units and have the same measure no matter what sort of energy we are measuring. There are no arbitary conversions, each unit is compatible with the others and we don't have to mix up conversion factors all over the place.

It doesn't matter who invented it, it works so well that is is far superior to Imperial measurement.

Having said that, re-tooling is very expensive and the transition very hard, and people are used to the system of measurement they were brought up with. It certainly sounds better to say "quarter pound" than "about 100 grams". Also, in various places, non SI units are very valuable, like Knots for navigation. In the end though, people do get used to new units and the SI system has such value it is worth considering.

Also, even if you did make your manufacturing in SI, what standard thread would you use? And what head for your screws - Phillips, Cross head, Posidrive etc. Standardisation goes on and on and on. Sometimes it is a blessing, other times a curse. Often its better to stick to what you know.

And 411A - I'm not envious of your measurement system at all - I just think its too unwieldy. Your arbitary use of a gallon being 3.78 litres is just as arbitary as the English gallon being 4.54 litres - neither is better.

[Rhumdo]

All very clever, but you're missing the point - 1 gallon = 8 pints... 8 pints of lovely foaming ale. Going out for an 8 pinter and a curry doesn't really translate into SI... 4 litres and a piquant, yet flavorsome, spicy dish?

It's not rocket science, if it was, the Mars Landers probably would have made it

[forget]

And 411A - I'm not envious of your measurement system at all - I just think its too unwieldy. Your arbitary use of a gallon being 3.78 litres is just as arbitary as the English gallon being 4.54 litres - neither is better.

Quite wrong. The Imperial job is FAR better. Why the Murcans chose to change it - only they know.

1 GALLON of WATER = 10 POUNDS.

Stuck in the jungle? You can do all sorts with that little gem.:ok:

[ornithopter]

Fair enough - that's one of the arbitary numbers I had forgotten.

I'm envious of your gallons now! :}