Hi all read the fcom2 page 676 etc and i know the different modes are for but was wondering what is the idea for the stby button is used for other than arming the aiii to display arm etc. Example Like if i select pri in the mode selection than if i press the stby i can get vmc, imc a111 etc so not quite sure on the stby operation if i select pri in the mode select button

From messing around with it a bit, it seem as thought whatever you have selected on the stby line, is what gets selected as the active mode the next time you press the "mode" button. So if you're in PRI mode, and you have IMC showing the stby line, the next time you press the mode button you'll go from PRI to IMC. Just try it and you'll see what I mean. So it's basically like a pre-select button, so if you know you'lI want to be in a specific mode at some point, you can select that on the stby line and then all you need to do is press the mode button once to activate.I could be way wrong, but that's what it seems like to me.

To activate AIII ARM, push the STBY function key on the HUD control panel. When armed, "AIII ARM" is displayed on the standby mode display line and "AIII ARM" is displayed on the combiner. Approximately five seconds after the requirements for ILS approach criteria are satisfied, the AIII mode is automatically activated

thx for that but stull doesn explain this though

what is the idea for the stby button is used for other than arming the aiii to display arm etc.

Exactly for that, no other thing. It's like a VHF radio with a stby freq... Just that you "preselect" a mode here.

Exactly for that, no other thing. It's like a VHF radio with a stby freq... Just that you "preselect" a mode here.

thx for ur reply