QUESTION: A question which arises periodically in instrument training is the issue of lost communications, and the phrase clearance limit. Section 91.185(c) tells us to fly the last assigned route to the clearance limit, and then if its where an approach starts to wait there for the ETE to run out, or if not, to go straight to somewhere from which an approach starts and wait there. The question is what to consider as the clearance limit in this situation?
For example, an IFR flight plan from KSBY to KFRG will have a route of flight like SBY V1 JFK, with KFRG in the destination block. The clearance would typically be cleared to Farmingdale as filed. Thus, KFRG is the clearance limit, but there is no navigation radio on that airport to which one can navigate direct other than with GPS or the like. The problem arising is there is no way for the non-GPS types to navigate from JFK VOR to KFRG other than via one of the instrument approaches. In normal operations, they’ll be given vectors to final, or at worst, cleared to one of the approach IAFs like FRIKK intersection via the DPK radial or direct to the Babylon NDB. However, if a non-GPS aircraft loses communications, they have no way to comply with the cleared route of JFK direct KFRG.
Many instrument instructors teach that in the lost communication situation, one should consider the last point in the route of flight block (i.e., JFK VOR), not the destination airport (i.e., KFRG), to be the clearance limit, and either hold there if the approach starts there, or if not, to proceed directly from that point to a point from which an approach may be commenced (i.e., FRIKK or BBN), and not try to fly over the airport first. Other instructors insist that since the airport is the clearance limit, you have to go there before you go anywhere else (i.e., go from JFK VOR direct to KFRG and then to FRIKK or BBN). Unfortunately, there’s no real way to do that.
I’ve searched the AIM and IPH, and haven’t found any clear guidance. Obviously, § 91.3(b) trumps § 91.185(c), so in this emergency situation, you can do what you think best to get on the ground safely. However, I’d like to know the textbook answer for how to deal with this situation.
ANSWER: Ref. § 91.153(a)(5); § 91.169(a)(1); § 91.185(c)(3)(ii); Instrument Flying Handbook FAA‑H‑8083‑15A on pages 11‑8 and 11‑9, the “Communication/Navigation System Malfunction” paragraph; FAA Aeronautical Information Manual, Chapter 4, para. 4‑4‑3 c. 2.; and Chapter 6, Section 4, para. 6‑4‑1 3. (c) on page 6‑4‑2; and FAA Aeronautical Information Manual in Chapter 5, Section 1, para. 5‑1‑8 b.; Since the aircraft is not GPS‑equipped, the pilot should have listed the IAF on the flight plan routing.
In your question, you said the pilot filed:
“. . . an IFR flight plan from KSBY to KFRG will have a route of flight like SBY V1 JFK, with KFRG in the destination block. . . . . The problem arising is there is no way for the non-GPS types to navigate from JFK VOR to KFRG . . .”
You are correct, there is no way for a non-GPS equipped aircraft to navigate from the JFK VOR to KFRG. It has always been my understanding that the pilot should file a routing that takes into consideration the aircraft’s navigation equipment capabilities. In accordance with the Aeronautical Information Manual in Chapter 5, Section 1, para. 5‑1‑8 b., it states, in pertinent part, “. . . : It is vitally important that the route of flight be accurately and completely described in the flight plan.” For the planned flight in your question, where the aircraft is not GPS equipped, the pilot should have filed a flight plan with the routing as either:
KSBY via V1 DPK to either BBN or FR with the destination as KFRG
or
KSBY via V1 JFK to either BBN or FR with the destination as KFRG
In the “Instrument Flying Handbook” FAA‑H‑8083‑15A on page 11‑8 (the paragraph noted as Communication / Navigation System Malfunction), it states “. . . However each IFR flight should be planned and executed in anticipation of a two-way radio failure.” If a failure of communications occurs in IFR conditions, the procedures that the pilot should follow in regards to routing, altitude, and when to leave the clearance limit are explained in the “Instrument Flying Handbook” and are also addressed in § 91.185(c).
Now in your example (i.e., SBY via V1 to JFK to KFRG), if a pilot were to lose communications where the clearance limit is KFRG, ATC would expect the pilot to fly via the ATC clearance routing and altitude to the IAF for the approach to the runway of intended landing. ATC would expect the pilot to depart the IAF as close as possible to the ETA, as calculated from the filed or amended (with ATC) ETE. In your example, the ATC clearance was SBY via V1 to JFK to KFRG, which makes the IAF as being either the Babylon NDB or FRIKK LOM/IAF, and then depart the IAF as close as possible to the ETA, as calculated from the filed or amended ETE. Meaning, the routing would be SBY via V1 to JFK to the IAF (to either the Babylon NDB or FRIKK LOM/IAF) to KFRG.
In the “Pilot/Controller Glossary” of the FAA Aeronautical Information Manual on page PCG C‑3, the term “clearance limit” is defined as: “The fix, point, or location to which an aircraft is cleared when issued an air traffic clearance.” In your example, you said KFRG was the “clearance limit” issued by ATC.
In the FAA Aeronautical Information Manual, Chapter 6, Section 4, para. 6‑4‑1 3. (c) on page 6‑4‑2, it states:
(c) Leave clearance limit.
(1) When the clearance limit is a fix from which an approach begins, commence descent or descent and approach as close as possible to the expect further clearance time if one has been received, or if one has not been received, as close as possible to the Estimated Time of Arrival (ETA) as calculated from the filed or amended (with ATC) Estimated Time En Route (ETE).
(2) If the clearance limit is not a fix from which an approach begins, leave the clearance limit at the expect further clearance time if one has been received, or if none has been received, upon arrival over the clearance limit, and proceed to a fix from which an approach begins and commence descent or descent and approach as close as possible to the estimated time of arrival as calculated from the filed or amended (with ATC) estimated time en route.
Just to let you know, we did discuss your question with our FAA Procedures Standards Branch, AFS‑420. It was their opinion that we should consider adding a new subparagraph (3) to the Aeronautical Information Manual, Chapter 6, Section 4, para. 6‑4‑1, 3. (c) on page 6‑4‑2 to address the scenario in your question. We are working this issue with our Commercial Operations Branch, AFS‑820, and we are proposing to add a new subparagraph (3) to the Aeronautical Information Manual, Chapter 6, Section 4, para. 6‑4‑1, 3. (c) that would read as follows:
(3) If unable to navigate to the clearance limit (such as in the case of where the aircraft is being radar vectored to a destination airport that does not have a ground‑based navigation aid), the pilot is expected to proceed to the IAF for the approach to the runway of intended landing via the routing and altitude as described in paragraph 6‑4‑1 c. 3(a) and (b). The pilot should then depart the IAF from where the approach begins, commence descent or descent and approach as close as possible to the expect further clearance time if one has been received, or if one has not been received, as close as possible to the Estimated Time of Arrival (ETA) as calculated from the filed or amended (with ATC) Estimated Time En Route (ETE).
Furthermore, we are also considering making another revision in the Aeronautical Information Manual, Chapter 5, Section 1, para. 5‑1‑8 b. 1. to read as follows:
b. Airways and Jet Routes Depiction on Flight Plan
1. It is important for the pilot to accurately and completely describe the planned flight route in the route section of the flight plan. In order to simplify the proposed flight route for ATC, pilots should file the routing via airways or jet routes established for use at the altitude or flight level planned. One of the reasons for a flight plan is to give ATC the pilot’s intentions in the case of lost communications. It is always recommended that pilots file flight plans assuming that their aircraft will encounter a loss of communications. Except when a pilot is being radar vectored, an instrument approach begins at an initial approach fix (IAF). Therefore, the IAF should always be listed in the route section of the flight plan. In a non-radar environment, a pilot should not accept a clearance unless the aircraft has the navigation equipment to fly to that clearance fix/location. We realize that in many of today’s modern aircraft, most are equipped with global positioning systems that allows a pilot to fly direct to a location regardless of whether the airport has a ground‑based navigation radio aid.
As a point of clarification about your one statement above where you stated “. . . Obviously, § 91.3(b) trumps §91.185(c), so in this emergency situation, you can do what you think best to get on the ground safely . . .” That statement is not entirely correct. Granted in an emergency situation (emphasis added: “emergency situation”), § 91.3(b) does permit a pilot to deviate from any rule in part 91 to the extent required to meet the emergency. However, a loss of communication is not automatically an emergency. Under a loss of communications, ATC would expect the pilot to comply with § 91.185, unless there is an emergency.
