Dear colleagues,
I've presented this in the Tech Log forum and received good operational pointers from flying colleagues, but I'm also interested these technical aspects, and that is your forte.
I'm discussing what technical implications it would have to loose all pitot tubes on the 737-800.
I'm also unsure if the GS indication in the ND is solely GNSS-based. Can't find it in the books either. Does anyone know?
I was told it would disappear in the event of all pitots being u/s.
But I'm sure one can get GS from selecting TK/GS from the ISDU on the aft overhead panel.
Then.. the F/D is an indication of where the FCC wants you to steer. To know this, the FCC receives information from the ADIRU via the FMC. E.g. flying straight and level, then pulling off the thrust will give us a pitch up command from the F/D to maintain altitude. To know this the FCC needs information on atmospheric conditions from the ADC in the ADIRU.
The maintenance manual also states that it will BOV (Bias out of view) if it receives unreliable info from the ADIRU.
But I was told one still has the F/D when all pitot tubes are u/s.
How can this be?
Thanks for all pointers
