Automated Air-Gnd Switching for Mode S
When considering an installation of Mode S, be aware that the current line of thinking from the CAA is that an automated means of Air/Gnd mode switching being required. (TGL 13 Rev 1 specifies a means of selecting GND mode on the ground although not specifically automatic)
With retractables that would normally mean squat switch connection, and whilst at present the CAA allow fixed gear to be approved without automated Air/Gnd they are considering insisting that all fits have automated switching.
This means that even the 'direct slot in' replacements need some modification to existing looms.
I guess if your installer already has a pre-approved series mod for the aircraft type they could get round this but otherwise expect to need squat switch wiring :-)
Regards
N