View Full Version : 747 maintenance manuals - issue from 1990 lacking detail
FairWeatherFlyer
30th Oct 2019, 23:42
There was a story on The Register a few days ago about an issue from many years ago with 747 manuals, there's a certain style to their articles and headlines which may annoy the uninitiated, but here it is:
The Register: I'm not Boeing anywhere near that: Coder whizz heads off jumbo-sized maintenance snafu (https://forums.theregister.co.uk/forum/all/2019/10/28/who_me/)
The technical side of the story is plausible if a bit sketchy but the journalist hasn't fully researched the story. It would be interesting to know what actually happened from the maintenance perspective, i.e. there must have been an update that went out with a notice of the previous omission? I'm also left wondering if this IBM RS6000 CD-Rom multimedia solution was the only format the manuals were available in? I.e. there's far less impact if 90% of the world was still using paper manuals at the time?
I think it would be useful to get a bit more detail on this to get the article amended with the extra information. The reporting of the comment about "I saw no press reports of bad maintenance." is a little disingenuous. I'm not sure I'd expect the mainstream press to pick up on the many updates and ADs and that comment doesn't even reflect a complete survey just what one (interested) person happened to notice or not notice.
DaveReidUK
31st Oct 2019, 08:42
After reading the comments on that article, I'll never complain about thread drift on PPRuNe again ! :O
The reporting of the comment about "I saw no press reports of bad maintenance." is a little disingenuous. I'm not sure I'd expect the mainstream press to pick up on the many updates and ADs and that comment doesn't even reflect a complete survey just what one (interested) person happened to notice or not notice.
The RS/6000 software used to display maintenance manuals may not have fallen under the scope of an airworthiness directive. The worst that could have happened is that, for a major failure in the procedures involved with maintenance work, the organizations using the defective tools/data/processes might be de-certified until the problem was remedied. It's the sort of process detail that, absent a newsworthy incident involving an aircraft, the mainstream press' eyes would just glaze over.:zzz:
FairWeatherFlyer
3rd Nov 2019, 10:19
The RS/6000 software used to display maintenance manuals may not have fallen under the scope of an airworthiness directive.
Indeed, but there must be some unfortunate combinations of events where you can end up in a risky state, e.g. instructed to replace A+B+C components and C is omitted from list, then if A+B are replaced but deteriorate due to absence of new C...
This does remind me a bit of modern e-readers. I've heard mixed opinions of these for technical books from "great, I can carry everything around" to "won't touch them because the repagination/formating ruins the content". Device independent output is surprisingly non-trivial.
Device independent output is surprisingly non-trivial.
This is true. The solution at Boeing (some time ago) was to abandon development of various tablet solutions for factory job control and go back to paper. In the 1990s, these tablets were custom devices running custom software. And pretty bulky and under powered compared to an iPad. The paper copy as authority to perform a particular function eliminated a lot of problems with the early hardware. References to drawings in the job paper which could be retrieved on RS/6000 workstations were pretty clear if the computer terminal failed to serve up the correct drawing.
The PDF document format is pretty reliable. In part because it is actually a paper document formatting language at it's heart. And using an off-the-shelf commercial reader tends to be more reliable than custom solutions. With millions of users, Adobe is likely going to hear about missing content pretty quickly if the general public starts to lose pages from their favorite novels.
MathFox
7th Nov 2019, 16:46
The PDF document format is pretty reliable. In part because it is actually a paper document formatting language at it's heart. And using an off-the-shelf commercial reader tends to be more reliable than custom solutions. With millions of users, Adobe is likely going to hear about missing content pretty quickly if the general public starts to lose pages from their favorite novels.
Though with sufficiently complex software, one will encounter bugs. I wonder how a PDF reader would act when there's insufficient memory to load (or transform) a large bitmap image. Will the entire image be dropped, some pixels dropped, etc?
I wonder how a PDF reader would act when there's insufficient memory to load (or transform) a large bitmap image.
In my experience, one gets the 'Loading ...' animation. Sometimes for an interminable period of time. The reader renders content within the viewing window. And re-renders if the document is scrolled. So I'm guessing that it's not so much the overall image size as the amount of information to be displayed within the selected view area.