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Under IFR and radar environment. ETA Delay of more than 20 min. Do I need to let ATC know?

Asked by: 1872 views Instrument Rating

What does it mean when someone ask to extend their clearance time?

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  1. Wes Beard on Sep 22, 2012

    I think there are two questions here:

    Under IFR and radar environment. ETA Delay of more than 20 min. Do I need to let ATC know?

    Under a radar environment, you do not have to report to ATC that you are going to arrive at your destination 20 minutes later than planned. They can see you on their radar screen and are tracking you. Reference AIM 5-3-3 section 2(b).

    You will also notice early on in section 5-3-3 that you are required to report to ATC if your average TAS differs by 5% or 10kts whichever is greater. This does not take into account the winds at your cruising altitude. If the winds are stronger than expected and you are late… no need to report. If, for some reason, you change power settings and that changes or TAS by more than stated above then you need to report.

    What does it mean when someone ask to extend their clearance time?

    Typically, pilots will receive clearance void times when (1) flow control is in use at the destination airport or (2) they are taking off IFR from an uncontrolled airport.

    Flow control is used when multiple airplanes are trying to land at the destination airport at roughly the same time. Instead of requiring airplanes to hold over a fix somewhere wasting fuel, they are held on the ground at their home field. The pilots will receive a clearance with a window to use that clearance. Southwest 1123 cleared to JFK as filed…. clearance vaild at 1125 void at 1129. The pilots may request they extend that time to finish last minute checks and other items.

    Departing from an uncontrolled field IFR requires the pilot to obtain a clearance from the FSS clearance delivery telephone number. They will be issued a clearance like this N123AB cleared to KELP as filed… clearance void if not off the ground by 1125am and not in contact with ATC by 1135am. These pilots, if they can contact FSS on the ground can also ask to extend their clearance time.

    There might be another example but I can’t think of any more.

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