Narrative:

This report is about a systemic issue in the us ATC system. It potentially could affect any high performance aircraft flying IFR in the united states. It concerns ambiguity with lost communications procedures that has arisen since the advent of more complex STAR arrival procedures. I have not actually had an event happen; as they are extremely rare. I am aware of the issue because I am required to discuss lost comm procedures during [training]; which I did on this flight. I have students review the lost comm procedures in flight manual (FM). I then ask them how they would get the aircraft on the ground in the event of lost communications in IFR conditions. 98 percent of them tell me that they would descend via the arrival both vertically and laterally. This is a correct response if they have been cleared to 'descend via'; but it is an incorrect response if they have not received a descend via clearance. Lost comm procedures in the fars; aim; and our FM all say to maintain the 'highest of 1. Assigned altitude 2. Minimum for IFR flight 3. Or expected; for the route segment being flown. Got that- 98 percent of pilots still give the wrong response immediately after reading the procedures in FM. Adding to the confusion; some arrivals; such as the Hustn4 in clt; have a lost communications box with instructions printed right on the arrival plate. But these would technically only apply after receiving a 'descend via' clearance. As an aside; after discussing this with ATC controllers at dca tower; approach; and center; the controllers are also unsure as to the proper procedure. They default to the technical answer; but not with any confidence. This issue exists because of advancements in technology and the resulting more complex arrival procedures with multiple altitude constraints. It also exists because the lost comm regulations were written when airlines were flying dc-4s and have never been updated. A further complication is that the FAA is a large bureaucratic organization and changing an far is hard. This problem can be fixed by adding one sentence to every arrival procedure. All they would have to do is have a lost communications box on every arrival plate and add the following sentence as the first sentence:'in the event of lost communications; fly the procedure laterally and descend to comply with the altitude restrictions on the arrival'. They could fix this in one revision cycle.

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Original NASA ASRS Text

Title: An air carrier Check Airman noted that lost communications procedures written 40 years ago and not updated since are difficult to correctly apply to the complex STARS designed for 'Descend Via' clearances.

Narrative: This report is about a systemic issue in the US ATC system. It potentially could affect any high performance aircraft flying IFR in the United States. It concerns ambiguity with Lost Communications procedures that has arisen since the advent of more complex STAR arrival procedures. I have not actually had an event happen; as they are extremely rare. I am aware of the issue because I am required to discuss Lost Comm procedures during [training]; which I did on this flight. I have students review the Lost Comm procedures in Flight Manual (FM). I then ask them how they would get the aircraft on the ground in the event of lost communications in IFR conditions. 98 percent of them tell me that they would descend via the arrival both vertically and laterally. This is a correct response if they have been cleared to 'Descend Via'; but it is an incorrect response if they have not received a descend via clearance. Lost comm procedures in the FARs; AIM; and our FM all say to maintain the 'highest of 1. assigned altitude 2. minimum for IFR flight 3. or expected; for the route segment being flown. Got that- 98 percent of pilots still give the wrong response immediately after reading the procedures in FM. Adding to the confusion; some arrivals; such as the Hustn4 in CLT; have a Lost Communications box with instructions printed right on the arrival plate. But these would technically only apply after receiving a 'Descend Via' clearance. As an aside; after discussing this with ATC controllers at DCA tower; approach; and Center; the controllers are also unsure as to the proper procedure. They default to the technical answer; but not with any confidence. This issue exists because of advancements in technology and the resulting more complex arrival procedures with multiple altitude constraints. It also exists because the Lost Comm regulations were written when airlines were flying DC-4s and have never been updated. A further complication is that the FAA is a large bureaucratic organization and changing an FAR is hard. This problem can be fixed by adding one sentence to every arrival procedure. All they would have to do is have a Lost Communications box on every arrival plate and add the following sentence as the first sentence:'In the event of Lost Communications; fly the procedure laterally and descend to comply with the altitude restrictions on the arrival'. They could fix this in one revision cycle.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.