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When to set your Transponder to Alt

Asked by: 7138 views Private Pilot

I'm on my 5th instructor and am being "re-programmed" on procedures... I am training in Class B and typically set the transponder to Alt when I cross from the parking area onto the taxiway... my new instructor suggest setting the transponder to Alt as soon as clearance gives me the squawk code.. any thoughts? Thanks, Jeff

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1 Answers



  1. John D Collins on Jan 01, 2016

    Here is the current guidance from the AIM dated 12-10-15, paragraph 4-1-20 (a)(3):

    Transponder and ADS-B operations on the ground. Civil and military aircraft should operate with the transponder in the altitude reporting mode (consult the aircraft’s flight manual to determine the specific transponder position to enable altitude reporting) and ADS-B Out transmissions enabled (if equipped) at all airports, any time the aircraft is positioned on any portion of an airport movement area. This includes all defined taxiways and runways. Pilots must pay particular attention to ATIS and airport diagram notations, General Notes (included on airport charts), and comply with directions pertaining to transponder and ADS-B usage. Generally, these directions are:

    (a) Departures. Select the transponder mode which allows altitude reporting and enable ADS-B (if equipped) during pushback or taxi-out from parking spot. Select TA or TA/RA (if equipped with TCAS) when taking the active runway.

    (b) Arrivals. Maintain transponder to the altitude reporting mode or if TCAS-equipped (TA or TA/RA), select the transponder to altitude reporting mode. Maintain ADS-B Out transmissions (if equipped) after clearing the active runway. Select STBY or OFF for transponder and ADS-B (if equipped) upon arriving at the aircraft’s parking spot or gate.

    I personally leave my transponder on and in the ALT mode at all times.

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