WX Deviation Question

bike21

bike21

9-5 Ruins Lives
In my years of running around thunderstorms and getting deviations I've only had two controllers not like what we're doing. Both have happened fairly recently when we've been cleared to 'deviate right' for instance and as we've come around the corner/edge of the storms we started a turn back toward our next fix before going direct. At all times we were still well right of our original course. The other day we popped out of high cirrus and had a buildup right in front that wasn't painting much so we took an admittedly bigger turn than normal back toward the left (but still well right of course). The freq was kind of busy so I didn't think it was super important to chime in about the left turn. Well, controller didn't like our turn and was a little peeved it seems.

So controllers, what is your expectation of our actions during deviations? In both cases we weren't given limits such as "advise me before going direct" or "no turns to the left before advising" etc. If we remain left/right of our original course shouldn't we have some latitude to move around?

I think communication is key and I'll try to chime in if we are making a larger course change but things are obviously dynamic up there. Thoughts?
 
At my facility they posted a notice about this a few months ago basically agreeing with your expectation. Some controllers apparently haven't gotten the message. We are generally the last ones to find out about important rule changes, as it turns out (not that this was necessarily a change, but I'll categorize interpretations the same way). To any newer controllers reading: Use altitudes during weather! Don't expect longitudinal/lateral to continue when the front aircraft is s-turning.
 
Yeah what he said. We were recently briefed on this as well (maybe around april). That a deviation up to 20 degrees right (for example), allows the pilot to deviate anywhere in that cone of airspace and to protect for such. I personally always go altitude when planes are deviating everywhere, I don't expect you to have time to chime in when you are gonna start back direct or if you need to weave left or right, as the frequency is probably heavily congested if deviations are happening, and you are legal to do so. If I can't use altitude I am likely going to try to narrow you down and instead of approving a deviation ask you what heading you need and assign that heading, advise if you need anything else. If you are going to do something odd like go back to your original course then go 20 right again thereafter, a little heads up would be nice, as I am going to assume you are done deviating (though I usually ask, as you know what they say about assumptions).
 
I always always always use altitude when pilots are deviating. If you request to deviate, you should hear something like "deviations left/right of course approved, maintain 7,000, when able direct XXX and advise." That's standard phraseology and what I use nearly exclusively. So as long as you advise, you're now direct, no one should be angry/confused/sad/gassy....
 
Misunderstandings like this are exactly why our manual was changed somewhat recently to mandate specific deviation instructions and, when able, instructions on what to do when the deviation is complete (AND a request for an advisory from the flight crew when the deviation is complete).

7110.65 2-6-4 nails it:

2−6−4. WEATHER AND CHAFF SERVICES
Click to expand...
g. When requested by the pilot, provide radar
navigational guidance and/or approve deviations
around weather or chaff areas. In areas of significant
weather, plan ahead and be prepared to suggest, upon
pilot request, the use of alternative routes/altitudes.

1. An approval for lateral deviation authorizes
the pilot to maneuver left or right within the limits of
the lateral deviation area.

2. If a pilot enters your area of jurisdiction
already deviating for weather, advise the pilot of any
additional pertinent weather which may affect his
route.

3. If traffic and airspace (i.e., special use
airspace boundaries, LOA constraints) permit,
combine the approval for weather deviation with a
clearance on course.

PHRASEOLOGY−

DEVIATION (restrictions if necessary) APPROVED,
WHEN ABLE, PROCEED DIRECT (name of
NAVAID/WAYPOINT/FIX)

or

DEVIATION (restrictions if necessary) APPROVED,
WHEN ABLE, FLY HEADING (degrees), VECTOR TO
JOIN (airway) AND ADVISE.

EXAMPLE−
1. “Deviation twenty degrees right approved, when able
proceed direct O’Neill VORTAC and advise.”

2. “Deviation 30 degrees left approved, when able fly
heading zero niner zero, vector join J324 and advise.”
Click to expand...

If they don't want you going on course yet then they should have done this:

4. If traffic or airspace prevent you from
clearing the aircraft on course at the time of the
approval for a weather deviation, instruct the pilot to
advise when clear of weather.

PHRASEOLOGY−
DEVIATION (restrictions if necessary) APPROVED,
ADVISE CLEAR OF WEATHER.
Click to expand...

All of these sections have "change bars" next to them in the body of the manual, indicating that these are recently changed items. So, it's newer material, however it's still several months old and some people aren't doing it correctly.
 
FM_Weasel said:
All of these sections have "change bars" next to them in the body of the manual, indicating that these are recently changed items. So, it's newer material, however it's still several months old and some people aren't doing it correctly.
Click to expand...

Guilty.
 
WOW using altitude separation when aircraft are deviating due to weather.........................what a novel idea!!!!!!!!!!!!!!!!!!! DUHHHHHHHHHH . What the hell are they teaching the new folks this stuff is ATC 101 at least for the Zs but should be for all radar facs. Also advising the pilot not to rejoin the course if you have traffic after a deviation is also ATC 101 stuff. The point is that any controller that dose not have there head up there but would include any instruction on what they except the pilot to due after deviating.
 
I have also witnessed a few instances over this summer, where I have given a "deviation right of course approved when able direct XXX" and then have had the pilot say "clear of wx going direct" only to turn back to their original course instead of going direct...after I had discontinued vertical with the a/c paralleling them in...only to then scramble to regain it. This was a foreign pilot, so I let that go as a language/procedural issue.

The other incident I had, after a right deviation the pilot advised direct XXX. I had again, an a/c on a parallel course descending next to them, and I noticed instead of diverging like they should be doing ~5 degree difference in course, they were in fact getting closer together. So I ask the pilot again "confirm you are direct XXX" answer "affirm". I run out the vector lines and they are not direct but basically on a 5 mile offset to the right of course. Not sure what they had put in but once I turned them further left and asked again, they fessed up that they hadn't entered it right. I assume you can enter an offset into the FMS and they never removed it when hitting direct, but I know nothing about flying those big jets I control lol.

But either way that is what I am here for...keep em separated, regardless if they are doing what you expect or not.
 
Let me ask you controllers another question related to wx deviations. This has happened many times and all were while I was under CPDLC, but I guess it could happen over voice just as well. So let's say we request a wx devation and the controller replies with, "deviation approved, report back on course". Let's say we had to go 30NM right of course. Here's the question: do you expect me to report back on course as soon as I'm done deviating and start turning left towards my original airway, or should I wait until I'm back on the actual airway before reporting back on course? I personally believe the latter is the correct answer, but most captains I fly with tend to stick to the former. Thanks in advance.
 
sigler said:
Let me ask you controllers another question related to wx deviations. This has happened many times and all were while I was under CPDLC, but I guess it could happen over voice just as well. So let's say we request a wx devation and the controller replies with, "deviation approved, report back on course". Let's say we had to go 30NM right of course. Here's the question: do you expect me to report back on course as soon as I'm done deviating and start turning left towards my original airway, or should I wait until I'm back on the actual airway before reporting back on course? I personally believe the latter is the correct answer, but most captains I fly with tend to stick to the former. Thanks in advance.
Click to expand...

Might be different in the oceanic world but I would want you to tell me when you are done deviating and going back direct whatever fix so I know you are on a fixed heading. Now in the oceanic world where you are on specific airways I'm not sure but I'd still imagine they'd want to know when you are done deviating.
 
sigler said:
Let me ask you controllers another question related to wx deviations. This has happened many times and all were while I was under CPDLC, but I guess it could happen over voice just as well. So let's say we request a wx devation and the controller replies with, "deviation approved, report back on course". Let's say we had to go 30NM right of course. Here's the question: do you expect me to report back on course as soon as I'm done deviating and start turning left towards my original airway, or should I wait until I'm back on the actual airway before reporting back on course? I personally believe the latter is the correct answer, but most captains I fly with tend to stick to the former. Thanks in advance.
Click to expand...

If you're just told to report back on course, I'd assume that there's no other traffic that's a conflict with you. So I think that waiting on your report that you're back on the airway is sufficient enough. Either way, doesn't sound like it's an issue. But I've never done the data-link stuff before.
 
sigler said:
Let me ask you controllers another question related to wx deviations. This has happened many times and all were while I was under CPDLC, but I guess it could happen over voice just as well. So let's say we request a wx devation and the controller replies with, "deviation approved, report back on course". Let's say we had to go 30NM right of course. Here's the question: do you expect me to report back on course as soon as I'm done deviating and start turning left towards my original airway, or should I wait until I'm back on the actual airway before reporting back on course? I personally believe the latter is the correct answer, but most captains I fly with tend to stick to the former. Thanks in advance.
Click to expand...

The oceanic system uses conflict probe to protect your flight. When you are on a deviation it is entered into the system and your protected airspace increases to in your example 30nm to the right of your course, and then probes for traffic out there, and applies applicable lateral/longitudinal separation from other aircraft/airspace. So by reporting "back on route" but actually being still right of course direct the next waypoint, your protected airspace to the right of you goes away, and you are no longer protected on your off course heading. If you want to advise that you are done deviating and are now direct XXXXX then we can do an ADS demand get your current position, clear you present position direct the next waypoint, which will wipe out the deviation, and then the system will be accurately protecting your flight. I would prefer you just report back on route, when rejoining your original route, or at the next waypoint when you fly over it. By not reporting back on route, the system will continue to protect for your deviation forever. So please, DO report "back on route" when you hit the next waypoint, or if you rejoin your original route/airway.

If you are ADS-C equipped as well, when you report "back on route" but you are actually still to the right of your original route, it will trigger a lateral deviation event, showing us that you are still deviating. These lateral deviation events are why if you decide i'll just go 5 miles to the right to avoid some weather and not tell anyone, you will likely get a clearance from us without asking, clearing you to deviate, or a DL asking if you need to deviate, or, if you have now deviated into traffic, you will be getting a phone number. Bottom line, if you want to deviate, ask us, or if you want to just do a little jog to the left greater than 2 miles without asking, shutoff your ADS. As the years go by, I would not recommend the shutoff of the ads move, we are now 30nm lateral and 30nm longitudinal on RNP4 equipped a/c down from 50/60nm depending on where you are, and Gander/Shanwick will be going down to 25nm in November. A little deviation will be getting closer and closer as the separation becomes lower, and this separation requires you to be connected.

If you don't have ADS, then just know by reporting back on route when really direct the next fix, you are no longer protected by the conflict probe, and it is possible for other traffic to be climbed/descended in what should have been your protected airspace to the right
 
I'll add something to Klkm post

Gander is only going down to half degree separation on the core track inside the NAT track structure only.

Initially it will only be used in this method, there will be ONE RLAT (reduced lateral) track.

In a year (or so) full RLAT separation should take effect
 
You must log in or register to reply here.
Back
Top