Originally Posted by
Fly Aiprt
Thanks Tobin, BDAttitude and clearedtocross.
Of course nobody suggested any FCC could be programmed in Java. That was an
example as to the basics of specifying code is all about managing exceptions and crosschecks. Sorry if it wasn't clear.
Here is a link to some research done in programming a 737 version some years ago.
http://www.cse.cuhk.edu.hk/~lyu/paper_pdf/00005291.pdf
Interesting to see what languages were tried, and what delays it takes for even some experimental version.
C, C++, Pascal and Ada are not uncommon.
And yes it appears the MCAS "fix" has been rushed and not really tested in the real world.
One wonders what would have happened if FAA was still under the influence of Boeing and had returned the airplane to flight...
I think it is a little unfair to say that the MCAS fix has been rushed, The requirement on the FCCs was completely changed - nothing to do with MCAS apart from that was why the FCC design assumptions were revisited. So now they don't run independently from what has been said they have to work with one shadowing the other. This in some areas is a large logic change. There will be a standard development test sequence of standard software unit test, bench test with avionics connected then to an aircraft simulation cab then to a live aircraft. Each time testing being carried out at different levels and then full regression testing to ensure nothing in existing code has been broken. It looks like a regression test on the live aircraft in one of the recent tests found a problem. That is why regression testing is done. As someone who has spent many 'happy' hours regression testing systems I can assure you it doesn't matter what the expertise of the programmer is, and what the pressure is from management it is rare that there will not be problems moving to the live environment, especially in real time systems. The subsequent fault fixes may even cause new issues to be found in what had been working code.