PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 1
Old 24th Jan 2012, 08:43
  #1129 (permalink)  
Join Date: Jul 2009
Location: France - mostly
Age: 80
Posts: 1,689

Thanks for the information on the BUSS.

Some time ago a post claimed that it displays AoA and nothing else. Would it be possible to retrieve information on how it works internally, i.e. what input data it uses and how these data are combined/processed to drive the display?

See for example AF447 UAS by Joelle Barthe
The BUSS is optional on A320/A330/A340. It is basic on A380, being part of the ADR Monitoring functions.

This indication is based on angle of atack (AOA) sensor information, and is therefore not affected by erroneous pressure measumements.

The BUSS comes with a new ADIUR standar (among other new system standards), where the AOA information is provided through the IRs and nor through the ADRs. This enables selecting all ADRs off without loosing the STALL WARNING PROTECTION.
The AOA information provides a guidance area in place of the speed scale. When the crew selects all ADRs OFF, then:

- The Back-Up Speed Scale replaces the PFD speed scale on both PFDs,

- GPS Altitude replaces the Altitude Scale on both PFDs.

The Back-Up Speed Scale then enables to fly at a safe speed, i. e. above stall speeds, by adjusting thrust and pitch.

Last edited by HazelNuts39; 24th Jan 2012 at 09:06. Reason: P.S.
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