Anonymous asked in Cars & TransportationAircraft · 6 years ago

Who should pilots listen to when they get a hit on the TCAS? The instrument or ATC?


I am a private pilot and I fly single-engine crates ( c-172 and c-150 ) under VFR conitions, mostly in uncontrolled airspace, sometimes in controlled airspace at larger airports. Although I don't use a TCAS for the type of flying that I do I am courious what the proper procedure is when pilots get a TCAS hit. Do they obey the instrument or listen to ATC?

I just read a story ( an old story ) about two airliners that nearly collieded over Japan in 2001. It appears from the story that the pilots of both planes along with the controllers faced the situation with more confusion than procedures. Here is a link for te article if anyone wants to read it,_Japa...

9 Answers

  • Favorite Answer

    It depends on the system installed. not all TCAS gives the pilot a‘Resolution Advisory

    TCAS I was developed to accommodate the general aviation (GA) community and the regional airlines. This system issues ‘Traffic Advisories’ (TAs) to assist pilots in visual acquisition of aircraft. TCAS I is mandated on aircraft with 10 to 30 seats, although TCAS II may be installed instead.

    TCAS II is a more sophisticated system which provides the information of TCAS I, and also analyzes the projected flight path of approaching aircraft and issues ‘Resolution Advisories’ (RAs) to the pilot to resolve potential mid-air collisions. TCAS II is required internationally in aircraft with more than 30 seats or weighing more than 15,000 kg.

  • 6 years ago

    TCAS. It will give the pilots of both aircraft instructions on how to not collide. Think for example if TCAS tells one plane to climb and another to decend, but one pilot listens to ATC who says the opposite of the instrument cause the controller doesnt know what TCAS is saying. Now both planes are on a collision course again. Thats why you listen to TCAS, its required to be followed by the airlines I know of.

    There are also times when you get a really good controller who is on his toes and lets you know up front your TCAS may go off in a minute but please do not follow it. In those cases when I know ATC is looking out that well I know of TCAS being ignored.

  • 6 years ago

    They should always listen to TCAS, it is the law to listen to TCAS. This is because a couple of years ago a DHL cargo plane and an aircraft carrying Russian schoolchildren crashed into each other mid air, this is because in one of the countries pilots were trained to listen to air traffic control and the other country was trained to listen to TCAS, both planes alarmed because they were at the same altitude and TCAS told one pilot to descend and one to ascend, ATC told the plane that was told to ascend to descend so both planes descended, consequently they collided. after that it was international law that planes should always listen to TCAS.

  • AIM-7
    Lv 5
    6 years ago

    TCAS would take priority. Its constantly scanning the airspace around your aircraft and is the first to alert of you of an intruder target. If another aircraft is coming directly at you, time is of high importance and I'm not going to go talking over the radio asking for bearing, altitude, and range information. I'm going to take the TCAS alert as valid and perform the appropriate evasive maneuver(s). The TCAS can alert you a lot fast than an ATCO can. Especially if the ATCO's workload happens to be high.

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  • TCAS gets triggered when ATC screwed big time...

    ...therefore, TCAS takes priority over the ATC who's currently NOT at the same page like reality is.

  • 6 years ago

    I believe that TCAS warnings are heeded above ATC.

  • 6 years ago

    TCAS is recommended to listen too

  • 6 years ago

    TCAS comes first, and it should be. Whenever you trust the ATC, this might occur:Überlingen_mid-air_...

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