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Procedure for loss of GPS inside FAF/FAWP…i cant navigate to what I cant see.

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Aircraft Systems, Commercial Pilot, FAA Regulations, Flight Instructor, General Aviation, Instrument Rating, Private Pilot, Weather

For this example, I'll reference the attached RNAV(GPS) RWY 18 at Ely Nevada. (KELY) However I'm sure we can find many examples of this situation.

You are flying this published approach into the mountain valley at Ely Nevada, just are inside the FAF (FEILL) descending through 7000 in solid mist & fog.

Suddenly you lose GPS functionality. (The screen goes out, a bird takes off your antenna, Russians hijack the satellites...whatever... The point is you no longer have access to GPS derived information)

Now, sitting in the soup with no Nav source, how do you navigate the missed approach? Your RW18 Waypoint and your first Waypoint along the Missed Approach track (ZOLOB) are both GPS derived.

I'm expecting we'll get a "this is how I would handle it" answer and I am interested to hear if someone has a checklist/procedure for this situation but I'm most interested in regulatory policy. Beyond the RAIM related stuff, I can't seem to locate any firm guidelines. 

https://aeronav.faa.gov/d-tpp/1901/05163R18.PDF

1 Answers



  1. Mark Kolber on Jan 08, 2019

    You can’t find any **firm** guidelines because there are none. You are dealing with an emergency situation.

    Here’s what you do have. Flying into an area with this type of terrain, it would have been a good idea to have had a plan to begin with. That’s kind of a key when flying into an area like this, whether VFR or IFR. There is plenty of guidance on that, starting with FAR 91.103’s mandate to have “all available information,” specifically including “alternatives available if the planned flight cannot be completed.” Yours is the type of question which shows how important that is.

    What would I do? In all cases I would begin a climb immediately.

    1. There is a VOR approach with a simple VOR missed. Based on that, I would fly direct to the VOR and execute that missed, calling ATC as soon as I got airborne.

    2. There is an ODP. In this case it’s much identical to the VOR missed.

    3. Assuming none of the above and no other navigational alternatives, I’d just do the best I could. Even with just the GPS plate, I have some idea what course I need to follow from my present position and what altitude I need to climb to to avoid hitting rocks. If it’s not the Russians, but the equipment in my airplane, nice to have an EFB with GPS. If it is the Russians, , and even if it was the Russians, there is information about the terrain in the area which might help.

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