Divergence
- Thread starter that1guy
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- Mike Monroney Aeronautical Center
It was in a briefing because of a situation that needed looked at. I’ll try to get an answer from the QCG. I use fixes for overflights all the time esp when an aircraft is on an airway. If I know the radial the aircraft is on I’ll just use 20 degrees for a little extra room but it helps me climb thru or descend thru without gaining 3 miles or stopping someone at an intermediate altitude. The way it was briefed was that for initial separation ( in this case off the runway ) headings must be used. And to me that contradicts the word “courses” in the .65
Wow. I've been to four facilities in completely different regions in my career (none in the East, I suppose), and all have accepted instructing an aircraft to proceed direct to a fix as part of divergence. Hell, two facilities had tools to facilitate this: One used a page on an IDS4 system recording what the direct heading is to relatively local airports/VORs from that airport, and the other had a Windows app called "Fixfinder" that would display the heading to any airport/VOR in CONUS from that airport.
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- Mike Monroney Aeronautical Center
Any chance someone could provide a link to FIXFINDER. Been trying to get that here for years. I also find it very odd at the assessment from the QCG.
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If you have NIDS, ask your NIDS person to ask their tech support contact. Its not an official app or anything... a controller made it and lets them use it.
I had it on a flash drive before I left my last fac, was going to contact the author to publish it here, but I think I gave the drive to the person taking over.
Stinger
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I've always just used a combination of Airnav.com and skyvector.com to get headings to other airports/vors/fixes.
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- Mike Monroney Aeronautical Center
We use skyvector here which is fine, my last facility had the fixfinder.
I agree with MJ that we need more info here. I mean if you issue a 280 heading to 1 and a direct XXX VOR which is a 300 to the 2nd and the 280 tracks a 290 because of the wind and the direct XXX VOR tracks a 300 because he's direct then yeah you're gonna have a loss there.
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- Mike Monroney Aeronautical Center
I inquired about the situation yesterday got a response from the FAA today unfortunately it was told to me and was not giving in writing. The response of “no fix for initial separation” was used for the specific situation that had happened here, which was first aircraft (C182) direct VOR (HDG 26
and second aircraft (CRJ9) Rwy HDG 243. It didn’t work mostly because of how the skyline tracked. What I didn’t like was the blanket statement “no fix for initial separation.” So that was what was questioned. They responded with, if you are going to use a fix or two fixes for divergence you must be able to prove that the courses will diverge. Therefore if you recognize that one or the other are not tracking a heading that will be at least 15 degrees then you need another form of separation or you need to get 15 another way. (Hard heading). I’m not overly satisfied with the response but I think it echoes what most of us feel that you need 15 degrees. However you get it they don’t care but you need it and need to prove you had it. The question started from the Briefing not specifically saying that this was only an assessment of the situation and not how they feel about divergence as a whole. Sorry to be long winded and if it’s not satisfactory in the response.
and second aircraft (CRJ9) Rwy HDG 243. It didn’t work mostly because of how the skyline tracked. What I didn’t like was the blanket statement “no fix for initial separation.” So that was what was questioned. They responded with, if you are going to use a fix or two fixes for divergence you must be able to prove that the courses will diverge. Therefore if you recognize that one or the other are not tracking a heading that will be at least 15 degrees then you need another form of separation or you need to get 15 another way. (Hard heading). I’m not overly satisfied with the response but I think it echoes what most of us feel that you need 15 degrees. However you get it they don’t care but you need it and need to prove you had it. The question started from the Briefing not specifically saying that this was only an assessment of the situation and not how they feel about divergence as a whole. Sorry to be long winded and if it’s not satisfactory in the response.See that's crazy to me ... If you can hypothetically stick a 15 degree protractor on the scope and show you've got 15 degrees, who gives a damn? Why is so much emphasis on headings when both the book and FAA say it's about their track not the heading... We all know there are days when 15 degrees doesn't buy you 15 degrees...
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No that’s a good explanation. It’s exactly what I would have expected. Them saying the fix isn’t good for divergence meant it can’t be used to satisfy the 15° rule without actually having 15°, which isI inquired about the situation yesterday got a response from the FAA today unfortunately it was told to me and was not giving in writing. The response of “no fix for initial separation” was used for the specific situation that had happened here, which was first aircraft (C182) direct VOR (HDG 26
but there’s always someone...But they'll let you have less than 15 degrees actual track if you issue a 300 and a 315. But a 300 and a direct that's supposed to be 315 doesn't count, if you don't get 15 degrees track, because headings and direct to fix are not the same.
See that's funny bc we've had people fry over 15 degree hard headings not buying true 15 and them pinning it on them needing 15 degrees track even w hard headings... Which by your explanation(s) is incorrect and it shouldn't have been an issue... Which I'm always on Team Less Rules/More Ambiguity... I guess I just always want 15 track, regardless of heading... Much like a 30 degree intercept for ils... Doesn't matter heading, just need 30 or less track...
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Im so glad I don't work at a facility that has the time to argue over this stuff
GulfBravoPapa
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Just use multi-function Z and it will tell you the aircraft's track (among a slew of other information I don't understand)
Mike Kilo
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This is where the whole “consider aircraft performance and characteristics” comes into play. If a Cessna blows into a B737 and you take no action to correct it, that’s on you. We use headings along with RNAV departures for separation, but we monitor the heading to ensure the track is correct.
That shouldn't have happened. When the 7110.65 was changed back in 2010 they provided an explanation with how the rule works. If you give a one aircraft 200 degree turn and another 215 and it ends up being less due to wind or other reasons then you're supposed to be clear
This is the official statement of the FAA briefing on it: http://tfmlearning.fly.faa.gov/publications/atpubs/ATC/BGChange2.htm
Now the issue about fixes and radar vectors is different. The 7110.65 change was for "assigned radar vectors".
From the PCG: "RADAR VECTORING [ICAO]− Provision of navigational guidance to aircraft in the form of specific headings, based on the use of radar."
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- Messages
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- Mike Monroney Aeronautical Center
Looking forward to being in your same position in March lol
