Originally Posted by
slip and turn
So how does a 737-MAX 8 or a 738NG or any other late model aircraft know when to transmit via ADS-B that it has become airborne? And if it does, and gets it wrong at 93kts groundspeed, against what are all its subsequent pressure altitude reports calibrated?
To meet the requirements of DO-260B 2.2.3.2.1.2 c 1 the aircraft will use the normal indication for the OFF message; weight off wheels, squat switch, rad-alt and set the airborne indicator in the ADS-B Extended Squitter message.