Unreliable airspeed and 2 ADR off
Thread Starter
Joined: Jan 2013
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From: Utopia
Unreliable airspeed and 2 ADR off
Hi guys,
In Unreliable airspeed checklist, under "Affected ADR identification" process there is a line that mentions to keep one ADR on. I understand that in the older checklist one ADR was kept on to maintain STALL WARNING protection. However, after the modification one ADR is kept on to prevent the flight control laws from using two coherent but unreliable ADR data. So, what data will flight control law use from the remaining ADR?
In Unreliable airspeed checklist, under "Affected ADR identification" process there is a line that mentions to keep one ADR on. I understand that in the older checklist one ADR was kept on to maintain STALL WARNING protection. However, after the modification one ADR is kept on to prevent the flight control laws from using two coherent but unreliable ADR data. So, what data will flight control law use from the remaining ADR?
Joined: Dec 2002
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From: UK
CMpilot1, if you are referring to an Airbus 320, 330/340, see Airbus WIN: https://www.airbus-win.com/wp-conten...ircraft_en.mp4
This may help.
This may help.
Joined: Jun 2007
Posts: 3,443
Likes: 39
From: Wanderlust
CMpilot1
I think you are talking about irreversible BUSS.When two ADRs are showing same value but wrong they will use that as correct rejecting the third and ELAC will use it to keep normal law erroneously. But since here all are faulty you switch off any two and aircraft will go in alternate law. The only data used is AoA for stall warning. The third is not switched off hoping for ice melting and recovery at lower altitude. But if it doesn't happen then the third is also switched off to get the BUSS which cannot be reversed.
I think you are talking about irreversible BUSS.When two ADRs are showing same value but wrong they will use that as correct rejecting the third and ELAC will use it to keep normal law erroneously. But since here all are faulty you switch off any two and aircraft will go in alternate law. The only data used is AoA for stall warning. The third is not switched off hoping for ice melting and recovery at lower altitude. But if it doesn't happen then the third is also switched off to get the BUSS which cannot be reversed.
Thread Starter
Joined: Jan 2013
Posts: 68
Likes: 0
From: Utopia
CMpilot1
I think you are talking about irreversible BUSS.When two ADRs are showing same value but wrong they will use that as correct rejecting the third and ELAC will use it to keep normal law erroneously. But since here all are faulty you switch off any two and aircraft will go in alternate law. The only data used is AoA for stall warning. The third is not switched off hoping for ice melting and recovery at lower altitude. But if it doesn't happen then the third is also switched off to get the BUSS which cannot be reversed.
I think you are talking about irreversible BUSS.When two ADRs are showing same value but wrong they will use that as correct rejecting the third and ELAC will use it to keep normal law erroneously. But since here all are faulty you switch off any two and aircraft will go in alternate law. The only data used is AoA for stall warning. The third is not switched off hoping for ice melting and recovery at lower altitude. But if it doesn't happen then the third is also switched off to get the BUSS which cannot be reversed.
Vilas,
Even in the aircraft that doesn't have BUSS has the same procedure as the one equipped with the BUSS
The above is the procedure of the aircraft that doesn't have BUSS.
The above is the procedure listed in 2014 FCOM. If you compare the old one and the new one, you will notice that the info about STALL warning protection is removed. You must be aware that a modification has been carried out routing the AoA through IR instead of ADR enabling STALL warning even with all ADRs off. So, I don't think keeping one ADR on is to provide STALL warning. For melting of the ice.....ok...maybe..
Joined: Jun 2007
Posts: 3,443
Likes: 39
From: Wanderlust
Vilas,
Even in the aircraft that doesn't have BUSS has the same procedure as the one equipped with the BUSS
The above is the procedure of the aircraft that doesn't have BUSS.
The above is the procedure listed in 2014 FCOM. If you compare the old one and the new one, you will notice that the info about STALL warning protection is removed. You must be aware that a modification has been carried out routing the AoA through IR instead of ADR enabling STALL warning even with all ADRs off. So, I don't think keeping one ADR on is to provide STALL warning. For melting of the ice.....ok...maybe..
Even in the aircraft that doesn't have BUSS has the same procedure as the one equipped with the BUSS
The above is the procedure of the aircraft that doesn't have BUSS.
The above is the procedure listed in 2014 FCOM. If you compare the old one and the new one, you will notice that the info about STALL warning protection is removed. You must be aware that a modification has been carried out routing the AoA through IR instead of ADR enabling STALL warning even with all ADRs off. So, I don't think keeping one ADR on is to provide STALL warning. For melting of the ice.....ok...maybe..
