Reporting Distance as DME/GNSS
 

Hi All

What is the general consensus on reporting distance as GNSS/DME on CTAFs? I've always found it peculiar someone would bother reporting distance as 30 GNSS to Doomadgee, considering I don't ever recall a DME being installed there. 30 miles would suffice for me, I will make the assumption you're using a GPS to get that distance.

It's like you're reading my mind. I love "approximately 31 nautical miles GN double S".

Have you determined you are 31nm from your GNSS or because you just flew over farmer bob's dam which is 3 thumb widths and a hair from the airport on the WAC? :ok:

Plus I was under the impression the AIP said to do it, but I'll that to someone who is annoyed by the use of "31 GNSS" to look that up.

The bigger question is: What is the source of the direction information?

I think the report should be: "Springfield traffic, ABC is three one miles, by gee enn ess ess (or e.g. Deduced reckoning), to the north west, by magnetic compass (or e.g. Directional Gyro) inbound, estimating circuit area two three, Springfield."

That results in substantially different decisions in my cockpit than if the report was merely: "Springfield traffic, ABC is three one miles to the north west inbound, estimating circuit area two three, Springfield." How can I possibly plan around that, if I can't figure out how you figured out where you are with reference to Springfield?

GNSS is Global Navigation Satellite System (GPS). Nothing to do with DME.

Provided the information references the ARP, and the pilot has an approval for the use of the GPS, it is endorsed in his/her logbook and the unit is certified for aviation use, then it is perfectly acceptable.

Personally I always said nm in CTAFs. Even in a jet. But that's just me.

You learn in this game your way isn't the only way, and there are many ways to get the job done within the rules safely.

Agree! It doesn't matter where it comes from; if it's possibly not accurate (3 thumb widths+hair), then say "approximately".

?? Give us an example of where the distances could be so different at a location that would result in a "substantially different decision".

Unless it is a report to ATC IAW ENR 1.1 21.3.3, keep the R/T verbal-diarrhoea-free and use "miles".

Wow, Bloggs, really?

Lead Balloon sums the whole thing up perfectly (USING SARCASM by the way) - it doesn't matter to the receiving station how you got the info - as long as it's accurate!!! :ok:

If the broadcast says the position is by reference to GNSS and DG, I will scratch my left arse cheek. If the report says the position is by reference to DR and magnetic compass, I will scratch my right arse cheek. :}

Something really needs to be done about getting a 'like' button on this forum.

Lapstrap undone, LB? :} :eek:

My understanding was it was only required to clarify the distance as DME/GNSS if there was a DME at the station you were reporting to, i.e. Tamworth for example. That was what I meant by the DME reference.

But great to know to know I'm not the only one!

I always treat position broadcasts from randoms with great skepticism. When I hear GNSS I drop the skepticism. Actually, no, wait, I'm still skeptical AF.

This is exceptionally good advice and many out there should take note :ok:

Oh, FFS, Leady! How could you get it so wrong? It should be your *right* arse cheek if by GNSS, and *left* arse cheek if by DR/compass/whatever.

Y'know, I used to respect your posts...until now.

"Oztraya, mate!" - at its best! Never, ever, will you hear this ridiculous distinction overseas...

You forgot about "by wristwatch."

At the speed at which some of youse guys travel, by the time you said all of that, I would bet London to a brick, that you're now a whole lot closer to around 25 'miles' inbound....
And, 'we' all know that 'we' navigate in NM, don't we?

Like, in the ole AFIZ days, a jet reporting at '30miles' would generally take about 7 mins 'exactly' to reach circuit area.....

Give or take ten seconds or so.....

Cheers:}

I'm embarrassed to realise I'd mixed up the northern and southern hemispheres. In the southern hemisphere the rule is, of course: "Scratchy lefty turning north and scratchy righty turning south."

Another important point made by AOTW. As you know, AOTW, the timing references are increasingly diverse and so it is increasingly important to include the reference in the broadcast. "By wristwatch/iPhone/iPad [with statement of IOS version] /Android [with statement of device and operating system version] / etc." That will determine which nostril I pick.

I've heard that Lead Balloon's primary time base, when flying is an elderly analogue clock radio. Apparently he listens to the AM radio "Shock Jocks" when in the cruise. It's a back up just in case the ADF goes bung.. :O