Re: Boeing 737 and 737 MAX software

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

On Fri, 12 Apr 2019 00:46:31 -0700 (PDT), tranngocduong@gmail.com declaimed
the following:

>
>I know nothing about the software. But I don't think it is written in Ada. If it was, programmers must have chosen a wrong subtype.
>
	It's Ada... (In the past, I was doing maintenance on the FMS "BootROM"
code -- which, while not the actual run-time flight software, is
responsible for doing CRC checks of the software and databases, reading new
software from dataloaders, and loading which application is to run based
upon external settings. The FMS software links with the same base "OS".

>In the crashed Ethiopian 302 aircraft, ~30 seconds before impact, the nose points 40 deg. toward ground, and the AoA indicates 75 deg. As 40 + 75 = 115 > 90 deg., this would imply negative airspeed.

	With a big enough tail wind, negative airspeed is possible... Also, AoA
is the relative angle of air flow over the wing, and independent of nose
attitude. An inverse micro-burst (air coming straight up from the ground,
rather than down from above) could register a high AoA even with the nose
pointing down.


-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
	wlfraed@ix.netcom.com