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Yeah nah
8th Jun 2022, 07:27
Can anyone offer any insight into the new Honeywell H3 FMGC standard now available on the 320? In particular, what is behind Airbus’s decision to prioritise the vertical path over selected speed when in a “latched on profile descent”?

15 years of pulling speed to comply with ATC speed requests and then possibly adding a bit of speed brake to maintain or regain the profile if slowing in DES mode, but now the aircraft is maintaining a “latched on profile descent” at the expense of the selected speed unless I muck about in the MCDU or select OP DES or VS, the latter two then requiring an adjustment to selected Altitude to comply with coded STAR constraints.

Someone should have said “If it ain’t broke, don’t fix it”.

Any real world experience managing this “not really selected speed” whilst “latched on profile”. How is it working for you?

Sidestick_n_Rudder
8th Jun 2022, 11:28
I’m not familiar with the new FMS standard, but it seems similar to Boeing VNAV, which keeps the profile even if it means flying significantly faster than the tgt speed.

it actually works quite well on Boeings. The only difference will be that instead of using speed brakes to maintain the path, you will use the speed brakes to maintain the speed…

PEI_3721
8th Jun 2022, 13:19
Is this change a reflection that ATC procedures prioritise computerised flight paths over speed; but speed - time - distance management still required ?

By constraining flight path (FMS Auto), it is more natural to use thrust - airbrake to manage speed opposed to using a secondary effect of these to manage flight path ?