Originally Posted by
BDAttitude
So there's a fix and they do not mandate it?!
Some combination of data have triggered this bug and 7 approches have been identified.
So who guarantees that no 7 + x approches exist right now or are inserted later with DB updates?
Still find it strange.
No direct knowledge of this case, but sometimes a software update may require an associated hardware update. So while installing the new s/w is easy and cheap, the associated h/w may not be. If an operator never plans to operate into one of the seven affect airports, they may not want to be bothered (or pay for) the associated changes.
Shortly after EIS of the 747-400, Boeing came out with an EICAS s/w update to correct some issues with the original s/w. However it wasn't just a s/w update, it required a hardware change as well. Well, there was a certain operator who couldn't be bothered to update the hardware and so wouldn't incorporate the update. This operator also happened to be the launch customer and so had most of the affected aircraft. So finally the FAA issued an AD mandating the new s/w. Due to the unfortunate wording of the AD, it meant that every single time Boeing updated the 747-400 EICAS software, Boeing had to obtain an 'Alternate Method of Compliance' (AMOC) to the AD (which isn't trivial).