Re: Boeing 737 and 737 MAX software

[Dennis Lee Bieber <wlfraed@ix.netcom.com>]

On Thu, 07 Nov 2019 17:12:53 -0800, Paul Rubin <no.email@nospam.invalid>
declaimed the following:

>Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:
>> 	Unless things have changed severely -- GE Aviation (formerly Smith's
>> Aerospace, formerly Lear Siegler) produces the 737 FMS software (and also
>> the processor boxes).
>
>It looks like Collins Aerospace (formerly Rockwell Collins) is now
>getting some heat over the flight deck software:
>
>https://www.nytimes.com/2019/11/07/business/boeing-737-max-collins.html

	Though "the displays" don't really process sensor information. The FMS
sends display instructions to the display boxes, which then format and
render the actual screens. Unless they believe the display boxes should
have taking those display instructions and done local matching (for
example, AoA sensor vs a gyro pitch angle, and then "red-flagged" the
display of those items).

	If Collins is now building the FMS processor boxes, they must be
building them to the same specification as the GE boxes -- since the
"BootROM" which GE provided the older boxes underwent updates for the MAX
model, yet was tested on the same old processor boxes (It won't run on the
very oldest as those had a different memory map -- pre-MAX BootROM used a
memory layout that was common to both generations of processor boxes; the
MAX software moved some stuff into a region that doesn't exist on the
oldest).

	I'm fairly certain that the FMS for MAX was also GE effort -- though
that may have been the waypoint/navigation/routing/fuel management stuff,
with Collins maybe doing the sensor and flight control integration stuff.
{I'd been on the BootROM/"platform" side of the building, FMS was another
room}




-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
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