A pilot has planned a flight to another airport, and the weather indications at the destination require an alternate airport to be included in the flight plan. An ILS and a VOR approach exist at the selected alternate airport with standard alternate minimums. The airplane to be flown is not equipped with an ILS glide slope indicator, but it has a VOR.

If the weather at the alternate airport at the estimated time of arrival to that alternate airport is indicated to be a 700 foot ceiling and 3 miles of visibility is this pilot in the above hypothetical situation violating a regulation by filing that alternate airport?

Another way to word this question is, does the approach that the selection of the alternate airport is based on actually have to be an approach the aircraft is equipped to execute?

Based on the regulation wording in §91.169 this is unclear. Do any relevant letters of interpretation exist? Otherwise, can you please provide some written evidence to support an answer on this point?

I have emphasized some of the wording pertaining to how this ties in with a flight plan below in the related FAA regulation. Nowhere in this wording does it say anything about the aircraft having to be able to actually execute any of the approaches mentioned, only that they're "published for that airport".

I am asking this because it seems contrary to common sense ADM, yet it does not appear to be prohibited.

§91.169(c) IFR flight plan: Information required.

(c) IFR alternate airport weather minima. Unless otherwise authorized by the Administrator, no person may include an alternate airport in an IFR flight plan unless appropriate weather reports or weather forecasts, or a combination of them, indicate that, at the estimated time of arrival at the alternate airport, the ceiling and visibility at that airport will be at or above the following weather minima:

(1) If an instrument approach procedure has been published in part 97 of this chapter, or a special instrument approach procedure has been issued by the Administrator to the operator, for that airport, the following minima:

(i) For aircraft other than helicopters: The alternate airport minima specified in that procedure, or if none are specified the following standard approach minima:

(A) For a precision approach procedure. Ceiling 600 feet and visibility 2 statute miles.

(B) For a nonprecision approach procedure. Ceiling 800 feet and visibility 2 statute miles.


1 Answer 1


I have not found any LOI's that cover this specifically but a broad interpretation of

§ 91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.


(d)Instrument flight rules. For IFR flight, the following instruments and equipment are required:


(2) Two-way radio communication and navigation equipment suitable for the route to be flown.

Once can broadly say that if you intend to fly an ILS (alternate or not) 91.205 requires suitable equipment i.e. an ILS receiver and CDI capable of displaying as such.

  • 2
    $\begingroup$ To put it another way you could say he can only take credit for that alternate if the forecast meets on the non-precision alternate minima since his a/c can only do non-precision approaches. $\endgroup$
    – John K
    Jul 30, 2019 at 3:07
  • 1
    $\begingroup$ @JohnK sure. That's common sense. Where is it written? $\endgroup$ Jul 30, 2019 at 3:56
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    $\begingroup$ Seriously, does everything need to either be specifically allowed or specifically prohibited? Have we lost our ability to discern intent? You know what the intent is here, right? If you had a mishap as a result of filing for an alternate where the mins were below what your equipment was capable of, would you feel comfortable explaining your decision making process to the NTSB? $\endgroup$ Jul 30, 2019 at 4:08
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    $\begingroup$ @RyanMortensen "equipment suitable for the route to be flown" is clear enough for me since the "route to be flown" could include the trip to the alternate. I don't think that requires too much legalistic parsing of language in this case. $\endgroup$
    – John K
    Jul 30, 2019 at 4:16
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    $\begingroup$ And don't forget the general regulation on "careless or reckless" operation of aircraft. $\endgroup$
    – user
    Jul 30, 2019 at 6:22

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