Readback September 2016 Issue
Reader Feedback: September 2016
I found the reader question and your response about squawking standby in the May issue interesting because Mode S transponders and especially ADS-B Out configurations have SBY/ALT positions when a GPS position is received rather than ON/ALT without a GPS position. At least that is how my Avidyne IFD540/AXP340 system works. The transponder powers up in SBY mode and automatically switches to ALT mode during the takeoff run. Perhaps Iím wrong, but my understanding is that the SBY position has a different transmission profile for Mode S than the ALT mode and that is reflected in what ATC sees.