Amiga500 wrote:Just to take a simple example of something that might fall somewhere between the cracks...
Are they reusing the 777's FBW system? Avionics, flight control computer, software stack, cabling specs, actuators etc?
If so - the top down examination will have to carefully consider the effects of operating it within a composite structure (considering things like Lightening strike).
If not - does that mean a complete re-write of the 777s FBW software stack and possibly even changes to the FCC depending on computational workload?
As usual, the devil is in the details.
http://interactive.aviationtoday.com/av ... -avionics/ tells us the amount of change in the 777X systems is a lot bigger than you are envisioning.
Everything from displays to EFB to wireless connections to cameras to wired data busses to central processors to FDRs to sensors to FBW system to data management system to actuators are changing.
This article was written in 2017 so the scope of the changes had to be evident by then, thus part of the planning.
A lot of this stuff has its origins in the 787 but also a lot of it is changed or expanded upon for 777x so it will need its own certification activities.
An interesting quote from QR's CTO:
New capabilities with the touch-screen displays and customer experience network will be the biggest operational changes, while the CCS will be the biggest change on the avionics front. The fact that this is a “connected” aircraft will also enable more streamlined maintenance activities like remote fault diagnostics, sending software to the aircraft and getting data from the airplane. This will be new for the 777, but does exist today on the 787.
I think the new CCS with new and more powerful General Processing Units alone makes the avionics system as a whole a whole new certification effort, not to mention all the features/systems that did not even exist on 777 "classic".
This is not MCAS shoe horned into an existing FCC and existing flight control design with roots in the 60s/70s.