Re: Boeing 737 and 737 MAX software

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

On Fri, 05 Apr 2019 14:16:20 -0700, Paul Rubin <no.email@nospam.invalid>
declaimed the following:

>Does anyone know anything about this?  It has been under some criticism
>lately.
>
>I have heard that the 777 software was almost entirely in Ada.  It also
>sounds as if Boeing's software operation may have slipped in recent
>years, not good news for the 737 MAX.

	Unless things have changed severely -- GE Aviation (formerly Smith's
Aerospace, formerly Lear Siegler) produces the 737 FMS software (and also
the processor boxes).

	However, I have the impression (from TV news) the software is
functioning /as designed/. Some reports have indicated that Boeing designed
the hardware (and corresponding software requirements) such that only one
sensor is used for the MCAS subsystem -- and a fault in that sensor results
in MCAS attempting to prevent a (non) stall by pushing the nose down. Some
hints in the news that Boeing is changing the requirements (well, in truth,
the news only says Boeing is changing the software) to have MCAS
cross-reference with other flight parameter data -- and making an optional
bit of hardware (additional sensors) standard.


-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
	wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/