AMC1 ACNS.D.ELS.020 On-the-ground status determination

• ED Decision 2013/031/R found in: GM Remote Aerodrome Air Traffic Services (ED 2019/004/R) Issue 2 (Jul 2020)

AMC1 ACNS.D.ELS.020 On-the-ground status determination ED Decision 2013/031/R The automatic determination of the on-the-ground status should be obtained from: (a) Weight On Wheel (WOW) sensor: When the aircraft is equipped with an automatic sensor to determine if the aircraft is on the ground (i.e. Weight On Wheel sensor), this sensor should be used as the on-the-ground status source of the transponder. For Aircraft with transponders that have access to at least one of the following parameters (ground speed, radio altitude, airspeed) the following validation check should be performed when detected ‘on the ground’ and the air/ground status should be overridden and changed to ‘airborne’ if [Ground speed > 50 m/s (100 knots) OR airspeed > 50 m/s (100 knots) OR radio altitude> 15 m (50 feet)]. Note: Care should be taken to ensure the wiring of the WOW to the correct transponder pins. (b) automatic algorithm : If ground speed, radio altitude, or airspeed parameters are being used in the algorithm and the ‘on-the-ground’ condition is being reported or if the on-the-ground status has been commanded via the TCS subfield, the on-the-ground status is to be overridden and changed to ‘airborne’ if : Ground Speed OR Airspeed > X or Radio height > 15 m (50 ft). Note 1: Care should be taken to ensure that the chosen threshold values of X are such that the aircraft can never report ‘on ground’ status when in the air, and should be based on the aircraft nominal performance. Note 2: Systems that support Enhanced Surveillance and ADS-B might use available airborne parameters in their automatic algorithm to determine if they are on the ground. More information can be found in Subpart D section 4.