ATC referencing DME when no DME present

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ATC often issues instructions with DME references to VFR traffic.

For example, "maintain X knots until 10 DME for sequencing" or "stay west of extended runway center line until 5 DME, cleared to land blah blah".

Now, I've gotten these instructions plenty of time in non-DME-equipped light singles.

Technically, should one be declining these as "unable" or just accept the fact that you know what they are asking and can comply visually (assuming the navaid is on field or at some other easily visually-referenced location)?
 
In this case, I have told them "Negative DME equipped, will comply using GPS". I've never had a negative response form ATC with this. I think that GPS is so common, ATC uses "DME" incorrectly. If you're not DME equipped, you can't accept the restriction.......

Of course you bring up a point I hadn't considered: are they asking for DME from the NavAid or from the runway. I think the clearance and restriction might clear it up depending on how it's used.
 
I fly /U all the time. IFR and VFR. I fly out of the same airport, at almost the same time, 5 days a week. After two years of doing this, I have to remind the controllers multiple days a week that I can't go direct.

In my case, "unable direct, request heading xxx to join Vyyy." And I've had to decline approaches and ask for opposite direction because of the lack of DME. They don't like it, but "unable" and what you can do seems to work most of the time.

As far as VFR, I'd just tell them negative DME and ask for a landmark.
 
Some controllers (including myself sometimes, no doubt) do use DME to mean "miles away." As long as you can do it, we don't really care what equipment you use to make the restriction.
 
Bernoulli Fan said:
Some controllers (including myself sometimes, no doubt) do use DME to mean "miles away." As long as you can do it, we don't really care what equipment you use to make the restriction.
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True, but do you actually state DME in those instructions?

I've thrown out more than my share of "until 5 mile final," etc and I think that is where the confusion may come into play here....and I don't care how it's measured, and it's really not THAT critical if I'm phrasing it that way.

But if someone is throwing out, "until 5 DME" that would seem a tad more critical to me in compliance, and I would want to know if a pilot couldn't do it as requested.
 
Might be different in the terminal environment. For center, if it's that critical, we'll just make the restriction 5 miles sooner to provide a pilot error buffer.

I don't think I've ever said "DME" on frequency, but probably on the line or in general conversation with another controller.
 
Bernoulli Fan said:
Some controllers (including myself sometimes, no doubt) do use DME to mean "miles away." As long as you can do it, we don't really care what equipment you use to make the restriction.
Click to expand...

I get "maintain 4000, crossing 30 M North EYW" a lot going to the keys, which I always thought odd - since the airway isn't really north so much as east.

Always figured that if it mattered that much, the crossing restriction would be at a fix, and being 100m out, ATC would say something if 700fpm wasn't good enough. And I've actually met a lot of those folks - they are on island time in Everglades/Miami :)

But a real question - I assume crossing restrictions like that are more advisory in nature?
 
drunkenbeagle said:
I get "maintain 4000, crossing 30 M North EYW" a lot going to the keys, which I always thought odd - since the airway isn't really north so much as east.

Always figured that if it mattered that much, the crossing restriction would be at a fix, and being 100m out, ATC would say something if 700fpm wasn't good enough. And I've actually met a lot of those folks - they are on island time in Everglades/Miami :)

But a real question - I assume crossing restrictions like that are more advisory in nature?
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4,000 @ 30 keeps you above that tethered ballon.......
 
Bernoulli Fan said:
Might be different in the terminal environment. For center, if it's that critical, we'll just make the restriction 5 miles sooner to provide a pilot error buffer.

I don't think I've ever said "DME" on frequency, but probably on the line or in general conversation with another controller.
Click to expand...

That makes sense. If you make the mistake (and it would be viewed as a mistake) of buffering 5 miles of space in the terminal environment, your nickname is likely to be "the human ground stop..." or something else with a lot of cuss words mixed in :)
 
I flew /x on a ferry flight, but then again I didn't have any radios or avionics either. I dont know when controllers starting getting so uppity about trying to get into class c with no xpndr.
 
A lot of the Old Guard still say things like this... just relax, they'll be retired eventually. ;)
 
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