Lost GPS on approach

jssmith.lh

jssmith.lh

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Goldthwaite flyer
I came across something today I haven't seen mentioned and couldn't find anything in formal or
informal references. It's when you're flying a GPS approach with a waypoint for a missed approach
hold and no other way to identify the waypoint. What's the procedure for the missed if you lose your GPS and you're not in contact with a controller?
 
You're down to "make a plan and fly it" at that point. Dial up 7600 on the way. Too many variables to answer the question as-is, like what other equipment is on board? Some aircraft have removed their other nav sources, so they're gonna be winging it worse than someone who can just navigate back to somewhere with an ILS... or VMC. Also leads into a discussion of how and why one might pick certain alternates and have appropriate fuel on board to reach them.
 
Ummm... I used to have a LORAN, and it never let me down, until the system was sabotaged.
 
Are you actually thinking lost comms or just not talking to Approach (i.e. On tower or CTAF or just can't get a word in due to congestion)?
 
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Hard to answer without knowing what else you have in the airplane, where you are, and what the weather is.
 
I've lost a GPS signal, while below Approach coverage, in the clouds. Not fun. The missed had a long runway heading segment, so I just held heading and climbed at Vy until I could regain contact. Then the GPS came back (I suspect there was a jammer on the beach below -- there was a big surfing event going on).

Terrain was on my right and open ocean on the left and straight ahead.
 
denverpilot said:
You're down to "make a plan and fly it" at that point. Dial up 7600 on the way. Too many variables to answer the question as-is, like what other equipment is on board? Some aircraft have removed their other nav sources, so they're gonna be winging it worse than someone who can just navigate back to somewhere with an ILS... or VMC. Also leads into a discussion of how and why one might pick certain alternates and have appropriate fuel on board to reach them.
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If you're still in comms range with ATC I wouldn't play with my transponder, I would however let them know my situation.
 
If you are unfortunate to be in a Cirrus, the procedure is pull the chute when the magenta line goes away.
 
KA550 said:
If you are unfortunate to be in a Cirrus, the procedure is pull the chute when the magenta line goes away.
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Man, you would think that would be automated by now.
 
Go missed, fly runway heading or whatever procedure states to the altitude give on plate. Navigate to nearest VOR or fix with radials hold and shoot appropriate approach.

You should have a low enroute chart with you that will show intersections that you can use.
 
GCA319 said:
?? If one is in ATC contact, ATC can give them alternate missed instructions regardless of approach type.
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Wally is speaking with technical accuracy - the term "Alternate Missed Approach" has a precise meaning in the TERPS world, and RNAV approaches do not have them. Many ILSes do.

I suspect you and @jordane93 are speaking more colloqially to mean a "substitute" missed approach such as radar vectors, rather than the officially designated and evaluated "alternate missed approach".
 
GCA319 said:
?? If one is in ATC contact, ATC can give them alternate missed instructions regardless of approach type.
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That is not correct. ATC facilities aren't trained in TERPs. Now, if ATC has the aircraft in radar contact they can provide a vector below the MVA (MIA center). Pilots need to understand such radar services are not available at many airports.
 
RussR said:
Wally is speaking with technical accuracy - the term "Alternate Missed Approach" has a precise meaning in the TERPS world, and RNAV approaches do not have them. Many ILSes do.

I suspect you and @jordane93 are speaking more colloqially to mean a "substitute" missed approach such as radar vectors, rather than the officially designated and evaluated "alternate missed approach".
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Ah, ok. I know what you're speaking of now.
 
aterpster said:
That is not correct. ATC facilities aren't trained in TERPs. Now, if ATC has the aircraft in radar contact they can provide a vector below the MVA (MIA center). Pilots need to understand such radar services are not available at many airports.
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Yeah,I know what you guys are speaking of now and you're correct and yes, substitute missed instructions are not available at most airport in the country...just the larger ones (and some of the smaller ones within the facilities airspace).
 
GCA319 said:
Yeah,I know what you guys are speaking of now and you're correct and yes, substitute missed instructions are not available at most airport in the country...just the larger ones (and some of the smaller ones within the facilities airspace).
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They are not available on RNAV IAPs. On ILS they are generally available where the missed approach goes to a VOR or NDB.
 
jssmith.lh said:
I came across something today I haven't seen mentioned and couldn't find anything in formal or
informal references. It's when you're flying a GPS approach with a waypoint for a missed approach
hold and no other way to identify the waypoint. What's the procedure for the missed if you lose your GPS and you're not in contact with a controller?
Click to expand...
If I knew there was a direction that was free of obstacles at and above my altitude, I would climb to the MSA in that direction until I could contact a controller. Otherwise, I would circle-climb to the MSA, with the initial turn away from relevant obstacles shown on the approach chart. I would squawk 7700 once I was established in the climb. (I would alter that procedure if other circumstances made it necessary or appropriate, e.g., restricted areas, high traffic areas, reaching VFR conditions, etc.)
 
aterpster said:
They are not available on RNAV IAPs. On ILS they are generally available where the missed approach goes to a VOR or NDB.
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So a controller who has radar contact with an aircraft all the way to the ground (like at a class C or B primary airport for example) cannot issue "substitute" missed instructions to an aircraft on an RNAV approach? Are you able to cite a source backing that up? Not arguing or anything, I'm legitimately curious. I've been given substitute instructions many times at larger airports on different types of approaches both when WX was low enough that there was a decent chance of a missed approach and in training situations (on IFR flight plans).
 
GCA319 said:
So a controller who has radar contact with an aircraft all the way to the ground (like at a class C or B primary airport for example) cannot issue "substitute" missed instructions to an aircraft on an RNAV approach? Are you able to cite a source backing that up? Not arguing or anything, I'm legitimately curious. I've been given substitute instructions many times at larger airports on different types of approaches both when WX was low enough that there was a decent chance of a missed approach and in training situations (on IFR flight plans).
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Did you read my Post #20? Here it is:

That is not correct. ATC facilities aren't trained in TERPs. Now, if ATC has the aircraft in radar contact they can provide a vector below the MVA (MIA center). Pilots need to understand such radar services are not available at many airports
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See attached excerpt from ATC Handbook.
 

Attachments

  • Vectors below MVA.pdf
    123.4 KB · Views: 7
I live in the sticks so many airports here don't have ATC comm to the MDA. Some don't have comm to the MSA.
I looks like the best option with comm is fly the missed heading(s) until you can get back with ATC. If it's lost
GPS -and- lost comm I'd fly the alternate. I'm sure there are other opinions :->
 
GTN flight manual supplement says to use the dead reckoning feature to fly to VFR IRRC.
 
bnt83 said:
GTN flight manual supplement says to use the dead reckoning feature to fly to VFR IRRC.
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Might want to check the manual again....

The dead reckoning feature doesn't exist in terminal mode. Only enroute. The question was about approaches. When you lose a signal while in terminal mode, all you get is a big box in the middle of the screen that says "No GPS Position."
 
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