Dead Reckoning IFR?

[Arnold]

In the TACAN thread the legality of Dead Reckoning (DR) while IFR was raised. My reading of the regs/AIM is that off airway routing is not dependent on the method of navigation, rather the ability of the ATC system to accommodate it.

I have essentially done this in the distant past. IFR with VOR + VFR only GPS. The routing has a kink. I want to cut a corner but I'm nowhere close to the destination VOR. I simply say: "XYZ Center, GoSlow N12345 requests xyz heading until able direct destination VOR." Often approved, or "I have your request."

This is really no different from DR except for the level of certainty.

 

[brcase]

I like the question...

So how about file direct to a fix or waypoint, like on an airway? Sometimes this seems like the only reasonable way to get from the departure procedure to the Low Altitude chart. Without GPS sometimes the only way to navigate to that point is by Dead reckoning until you pick up the airway. If I miss the fix by a mile or to left or right really doesn't seem like much of an issue.

Brian

 

[tonycondon]

look up the note "MEA Gap" which still exists at least on one segment Southeast of Salt lake City. Dead Reckoning is the expectation since nav signal is not guaranteed at the MEA. and that is on an airway!

 

[chemgeek]

In the TACAN thread the legality of Dead Reckoning (DR) while IFR was raised. My reading of the regs/AIM is that off airway routing is not dependent on the method of navigation, rather the ability of the ATC system to accommodate it.

I have essentially done this in the distant past. IFR with VOR + VFR only GPS. The routing has a kink. I want to cut a corner but I'm nowhere close to the destination VOR. I simply say: "XYZ Center, GoSlow N12345 requests xyz heading until able direct destination VOR." Often approved, or "I have your request."

This is really no different from DR except for the level of certainty.

Prior to IFR GPS (but with a non-TSO GPS or even a LORAN on board) it was definitely possible to get a direct-to vector if in radar coverage, e.g. "NXXXXX requests direct KXXX, a vector of 036 would work well" (wink, wink, nod, nod). This was granted as often as not in non-congested traffic areas, and I'm sure ATC was on to where the heading was coming from. As long as radar coverage was available, and the assigned altitude was above MVA, all was good. The non-TSO GPS or LORAN course was always a lot straighter and more reliable than the VOR airway tracking.

 

[MauleSkinner]

A radar vector is still technically a radar vector, even if it’s based on a DR solution.

 

[luvflyin]

Prior to IFR GPS (but with a non-TSO GPS or even a LORAN on board) it was definitely possible to get a direct-to vector if in radar coverage, e.g. "NXXXXX requests direct KXXX, a vector of 036 would work well" (wink, wink, nod, nod). This was granted as often as not in non-congested traffic areas, and I'm sure ATC was on to where the heading was coming from. As long as radar coverage was available, and the assigned altitude was above MVA, all was good. The non-TSO GPS or LORAN course was always a lot straighter and more reliable than the VOR airway tracking.

Yeah. I was getting ready to give a FAR91.### equipment suitable to route being flown and VFR only GPS don’t cut it speech. But once you con the controller into giving you a vector you’re good to go. You ain’t DR’n anymore.