ADIRS wind
Joined: Aug 2011
Posts: 43
Likes: 0
From: Tokyo (ENRI)
There are some delays in the ADIRS for the wind speed and direction. Mostly due to filtering of the signal and some computation delays. But we talk 50 - 100ms here. I am not aware of a significant specific delay for the instantaneous wind.
Joined: Dec 2002
Posts: 2,775
Likes: 353
From: UK
I am not familiar with the A320, but previous discussions suggested lag / filter, or smoothing delays of up to 30 sec. This provided a reasonable estimate of average wind speed; and although instantaneous wind can be quickly accessed, it may not be ‘now’, nor consider gusts.
“Wind speed and wind direction are available parameters in FDM data that are calculated in FMS. However these parameters cannot be used for analysis because it is known that FMS wind has a velocity bias of several knots, and a direction bias of several degrees. These deviations are caused by inaccuracies in the calculation of the drift angle, from the aircraft sensor data.”
https://www.futuresky-safety.eu/wp-c..._D3.4_v2.0.pdf
related:-
https://core.ac.uk/download/pdf/53034171.pdf
https://core.ac.uk/download/pdf/53034581.pdf
https://www.skybrary.aero/bookshelf/books/2069.pdf
“Wind speed and wind direction are available parameters in FDM data that are calculated in FMS. However these parameters cannot be used for analysis because it is known that FMS wind has a velocity bias of several knots, and a direction bias of several degrees. These deviations are caused by inaccuracies in the calculation of the drift angle, from the aircraft sensor data.”
https://www.futuresky-safety.eu/wp-c..._D3.4_v2.0.pdf
related:-
https://core.ac.uk/download/pdf/53034171.pdf
https://core.ac.uk/download/pdf/53034581.pdf
https://www.skybrary.aero/bookshelf/books/2069.pdf
Joined: Aug 2011
Posts: 43
Likes: 0
From: Tokyo (ENRI)
vilas
Which wind vector is this? Certainly not the one displayed on the ND. OP asked about the ADIRS calculated wind vector. There is no real delay in that calculation. It simply uses track/inertial velocities/TAS and some attitude parameters to calculate instantaneous wind.
Which wind vector is this? Certainly not the one displayed on the ND. OP asked about the ADIRS calculated wind vector. There is no real delay in that calculation. It simply uses track/inertial velocities/TAS and some attitude parameters to calculate instantaneous wind.
