If faster proc. chips are used, must an aircraft go through new certification?

[Ignition Override]

A couple of pilots said that if an Airbus gets faster chips for the FMC, new testing is required by 'our friends' at the FAA. Some of our A-320 pilots are not at all impressed with the speed on our A-320/319, and I certainly was not when flying the 757 a few years ago.

Are these standard products during production, or based on airline-specific FMC etc price options? Our A-320s seem to have a limited load when departing SAN on a fairly long route, due to second-segment requirements with the limited engine FADEC settings, from what I heard years ago. If so, are the FADEC settings for short- or long-term engine wear?

[NWSRG]

I was going to ask a similar question myself. Given the massive increase in computing performance since the A320 was introduced, is the system hardware and software updated at any stages to take advantage of this. Presumably, the entire control systems would have to be retested exhaustively before these changes could go live. Maybe it is just easier to stick with old technology until the next generation arrives? Also, given the time difference between them, would there be many differences in the hardware / software of, say, the A321, A320, A319 or A318?

[ICT_SLB]

Speed doesn't really come into it. Most avionics still use X86 chips because the computing requirements are well below that needed by the average PC. A lot of these older chips are no longer available for which one solution is to rehost the software on to Pentiums or similar. The problem with this is that the code may not work without a LOT of modifications. Brand H ran into this big time when they did their Gen Av programme a few years back and it took a long time to get all the bugs out even with - or maybe because of - autocoding. Don't forget that for any critical task you have to requalify the software to DO-178B which can be horrendously expensive.

One of the additional problems with FMCs is that, because of the CDU interface, they're getting a lot of tasks for which they were not designed. This means that not only must the new software be qualified to an appropriate level (more critical = more testing)but also the original core might need to be updated too if its level is no longer appropriate.

[mono]

Hi there,

The airline I work for has put at least 4 software mods onto the Bus FMGC's since I started.

It is the equipment that has to be certified not the whole a/c.

I have even carried out software updates on the line using a dataloader (either onboard or using a portable loader)

This applies to all a/c equipment and there are specific airworthiness notices which pertain to the various software which can be loaded. (AWN #43 is one)