airplane radios

Lost of Comms under IFR

If a loss of communication occurs in IFR conditions, you must continue the flight according to the acronym “AVEenue of FAME”. Let’s go over the components of the acronym:

  • A: Fly the assigned route as per last ATC clearance received.
  • V: If being vectored, fly the direct route from point or radio failure to the fix, route, or airway specified in the vector clearance.
  • E Fly the route that ATC has advised you to expect in a further clearance.
  • F Fly the route filed on the flight plan.
  • A Fly your last assigned altitude
  • M Be aware of minimum altitude (MEA) for IFR operations
  • E Fly the altitude ATC has told you to expect in a further clearance.

Note that “AVEF” refers to the route, while “AME” refers to altitude. 

Once reached, you need to have a plan in place to leave the clearance limit. Be sure not to descend below MEA before being established on the approach.

When experiencing a two-way radio failure, it is your responsibility to select an appropriate altitude for the particular route segment being flown; and to make any necessary altitude adjustments for subsequent segments.

If you have received a “expect further” communication that contains a higher altitude than what is currently being flown at an upcoming waypoint or time, maintain either the last assigned altitude or MEA (whichever is higher) until you reach that time or fix. Climb to the expected altitude upon reaching the time or fix. If the “expect further” communication contains a lower altitude, either the last assigned or MEA should be maintained (whichever is higher) until the time or fix that was specified to leave your clearance limit is reached.

If below Emergency Safe Altitude “ESA” (within 25 – 100 miles) or the Minimum Safe Altitude “MSA” (within 0 – 25 miles) and not established on an approach; make a climb above the relevant safe altitude until you are established on the approach.

If you are given an altitude to expect and make the climb to that altitude before the radio failure occurs, it is no longer “expected”, and the last assigned altitude or MSA should be flown; once again, whichever is higher.

If receiving an EFC containing a lower altitude, maintain either assigned altitude or MEA (whichever is highest) until the designated time/fix is reached.

 

Leaving the Clearance Limit:

Once reaching the Initial Approach Fix, commence the descent and approach as close as possible to the expected “further clearance time” if one has been issued, or as close as possible to the ETA calculated from the flight plan or amended with ATC if a further clearance time has not been issued.

If no time or fix was received,  start the descent as described above over the clearance limit; and proceed to the fix from which the approach begins.

 

While in the Pattern

 

 

 

 

 

If comms are lost in the pattern, look for the green light gun signal from the tower (signifying you are cleared to land). If no lights are received by the tower on your first approach, fuel permitting, go around. Land on the second approach if no light gun signals have been received from the tower. You can refresh on your light gun signals by viewing the picture above!

 

Radar Approaches:

Initiate lost communication procedures if no transmissions are received for 60 seconds while being vectored to final, 15 seconds while on ASR final approach, or 5 seconds while on PAR final approach.

If unable to reestablish communication and maintain VMC, proceed with published IAP  or previously coordinated instructions.

Maintain the last assigned altitude or MSA (Whichever is higher, or ESA if beyond 25 NM) until established on an instrument approach.

Be aware of where you are in relation to the missed approach point. You can climb, but don’t turn until you reach MAP.

So What About IFR Lost Comms in the Real World?

If you lose your comms while flying under IFR there are some commons sense steps you can take to ensure the best outcome possible for your flight.

Lost Communications while in VFR Conditions:

  • 14 CFR 91.185 is clear to say: “If the failure occurs in VFR conditions, or if VFR conditions are encountered after the failure, each pilot shall continue the flight under VFR and land as soon as practicable.”
  • That means if you are in VMC or encounter VMC after you lose comms, squawk 7600 and proceed to land as soon as practicable under VFR conditions (basically land at the first airport that works for you safely and logically).  Towered or non-towered airport does not matter, choose the best safe choice and land.

Lost Communications while in IMC (Instrument Meteorological Conditions)

  • Follow the steps outlined in the beginning of this article (AVEF-AME).  But also use common sense….
  • Check your Mic and Headphone jack and ensure your headset is plugged in.
  • Ensure you do not have a stuck mic (you may notice a TX annunciation on your radio if you do or hear the sidetone).
  • Check the volume on your radio, test the volume by turning of the squelch (pulling the volume knob or pressing the “SQ” button).
  • It is rare to lose your entire radio all at once, did you recently touch any buttons or switches on the audio panel or intercom? If so, flip them back to previous positions.
  • Try the last known frequency you were on.
  • Try reaching another ATC facility on 121.5 (guard frequency).  Transmit “Any station, your callsign, looking for name of ATC facility you are trying to reach”  Alternatively you can transmit “In the blind your message, in the blind”.  While “in the blind” is not something commonly heard on the radio, if an ATC facility hears it on guard or any other frequency they should know you are transmitting blindly hoping someone hears you, but you do not have two-way radio comms with any facility currently.  “In the blind” does not refer to you being in IMC.
  • If you establish contact with another aircraft you can ask them to relay your callsign to ATC and have them give you a new frequency to try.
  • Squawk 7600, continue listening, disable squelch, you may be able to receive and not transmit, perhaps you will be able to follow instructions or acknowledge instructions with an IDENT.
  • Try listening for ATC over VOR frequencies (using your NAV radio).  They may try to relay instructions to you via a nearby VOR frequency.

Example IFR Lost Comms Procedure:

  • You are flying east from MLD Malad City VOR direct Kemmerer Muni (EMM).  You were assigned 9,000′ and told to expect 11,000′ in 10 minutes.  Your filed ETA at EMM is 1519.  The time now is 1442 and you experience two-way radio failure.  You had filed MLD to GEGME then EMM.
  • In this case we need to immediately determine our altitude we need to be at.  We use AME (assigned, minimum altitude for IFR operations, or expected), and we chose the highest of the three to fly until we arrive at an approach which would allow us to descend lower.  In this case our altitude will need to be 13,000′ as that is the lowest IFR altitude to fly east bound off route (OROCA).
  • We would fly direct EMM at FL130.
  • Our route is determined by either the Assigned, Vectored, Expected, or Filed (in that order AVEF).  In this case we had filed MLD to GEGME to EMM, but were last assigned direct EMM.  You should fly direct EMM, then turn outbound on the approach course (assume using the RNAV RWY 16 approach).  You will fly outbound to MIKAE and you can begin descending to 11,700′.  You arrive at MIKAE at 1513, so you enter the hold (you can continue descending in the hold to 11,700′ if you have not already reached that altitude).  You will leave the hold as close to 1519 as possible and proceed inbound on the approach, following the published step down altitudes (treat it as being cleared for the approach at 1519).  Pray you break out early and can land.

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