Originally Posted by
tdracer
I'm right in the middle of that program, and I can absolutely guarantee that event had absolutely nothing to do with software - glitch or otherwise. You're basically just making
up.
It is related to Ice Crystal Icing - a poorly understood phenomena that has also affected CF6, PW2000, and GE90 engines over the years.
GE is looking at addressing the GEnx issue using software, but that's just because that can be done quicker and cheaper than a hardware change. It's also far from a given that the s/w change will actually work.
I am not "making stuff up" the information came from that unreliable source Aviation Week.
"
Boeing says the flight test effort is focused on “verifying operational elements” of a change to the engine control software. The testing included monitoring the development of ice crystals on the GEnx-2Bs powering RC021, one of the company’s test airframes that has recently been used to evaluate fuel system upgrades and other performance improvements. The fully-instrumented aircraft was originally designated for 747-8I launch customer Lufthansa, but was retained as a test asset after the German carrier opted not to take the modified airframe.The software changes to the GEnx-2B full authority digital engine control unit are designed to help the engine itself detect the presence of ice crystals when the aircraft is flying through a convective weather system. If detected, the new algorithms will schedule variable bleed valves to open and eject ice crystals that may have built up in the area aft of the fan, or in the flowpath to the core. The modification to the GEnx control logic leverages similar changes made to improve the ability of the CF6 to operate in similar icing conditions."
Boeing, GE Test Upgrades To Counter Engine Icing
And to return to my original point if there is an error in that 'new' software (like an incorrect assumption on the effects of icing (e.g, whether liquid water can be found at -40C above FL400 - it can) and therefore what changes are required in the engine; then the engines' software could all make the same incorrect decision on icing. I am not saying that they will I am saying that they could, there is no such thing as error free software or error free design (unless of course you have 'fixed the last bug' ) The software design/code itself becomes the common mode failure point and the number of engines is immaterial.