weather deviations in non-radar IFR

[apcooper]

It is my understanding in non-radar IFR, ATC usually wants you to be on an airway. This made me wonder how they feel about approving deviations around CB's and stuff like that. Obviously FAR 91.3 applies in that no sane pilot would fly through a cell since if ATC denied a deviation request, but short of the "E" word is there a clever way to work with ATC in situations like thses?

 

[avbug]

Acooper,

Non-airway flight is just as common in nonradar environments as it is under radar coverage.

If you need to deviate for weather, deviate, period. If I'm far enough out, I'll do ATC the courtesy of requesting a turn right or left, or asking ATC which way they want me to go where possible. However, I won't hesitate to inform ATC I'm deviating, as opposed to making a request.

Be prepared to say "unable," but also be prepared to inform ATC of your intentions, and then execute them, when necessary. Use of the "e" word isn't necessary. You always have the right to fall back on emergency authority if indeed one exists (or if you believe one does, or might), and shouldn't hesitate to use that authority...but remember that we're talking a course deviation here, not a regulation deviation, and the issue of emergency authority to deviate from a rule or regulation doesn't necessarily apply.

Further, don't let yourself get painted into a situation that becomes an emergency. Make your request, and if unable to get satisfaction, inform ATC what you will do, as opposed to what you request.

 

[GravityHater]

Is mora not always above minimum radar coverage for enroute flight?
If you offer that you can maintain terrain separation (and there is no traffic) I bet they will give you no hassle.

 

[minitour]

Is mora not always above minimum radar coverage for enroute flight?

I wouldn't think so...plenty of non-radar enroute flight out there, isn't there?

-mini

 

[Singlecoil]

Is mora not always above minimum radar coverage for enroute flight?
If you offer that you can maintain terrain separation (and there is no traffic) I bet they will give you no hassle.

Just the opposite. In mountainous terrain, grid MORA is almost never above minimum vectoring altitude. Generally in non-radar, they are separating traffic with altitude. A lateral deviation won't usually cause a traffic conflict. The airway is 8nm wide as well, so it really isn't necessary to tell them unless you are going past 4nm from the centerline of the airway.

 

[Vector4fun]

Hey, it's non-radar, how would we know if you didn't tell us??


(That DID happen more than a few times...)

 

[avbug]

For reasons that are unclear to me to this day, ATC once gave me a 1 degree vector. Something along the lines of "say heading," two seven five..."turn left heading two seven four."

In that spirit of spite and pettiness, I submit one should request deviations of more than one degree and greater than 50 yards.

"Poncahonca Center, Oblivion Six Five Six requests a turn six degrees left for a three hunded yard deviation for a flock of gypsy moths."

"Oblivion Six Five Six, Poncahonca Center, unable six degrees left at this time, I can give you seven left or five right, your discretion. Remain at all times within six hundred yards of the airway, opposite direction traffic your flight level on each side. Advise when back on course."

"Poncahonca Center, Oblivion Six Five Six, request eight degrees now and we'll the full six hundred yards. We're, ah, we're closer now and we have a visual on the moths. There appear to be several of them in formation, and they're giving us the eye."

"Oblivion Six Five Six, Poncahonca Center, standby while I coordinate that."

"Poncahonca Center, Oblivion Six Five Six, standing by. Please hurry."

"Oblivion Six Five Six, Poncahonca Center, Deviation eight degrees left of course approved. Opposing traffic has been given an emergency descent and the airspace is yours. Can you identify the genus and species of the moth?"

"Poncahonca Center, Oblivion Six Five Six, copy the deviation, apologies to the other crew. Unable species, but definitely genus porthetria. Standby while we maneuver closer for a look."

"Oblivion Six Five Six, Poncahonca Center. Advise exercise extreme caution. Attention all aircraft, report six seven miles north Squabbledabble VOR, large formation Porthetria sighted, believed to be dispar, exact species unknown. All aircraft in vicinity with allergies, advise immediately."

"Poncahonca Center, Oblivion Six Five Six, disregard PIREP regarding Porthetria Dispar. Returning on course."

"Oblivion Six Five Six, Poncahonca Center, copy your report. Can you advise what it was that you saw?"

"Poncahonca Center, Oblivion Six Five Six, it was definitely Dispar species, a true Gypsy Moth. We appear to have been late in the deviation request, and have taken the entire gaggle or flock or whatever you call them up the #2 intake."

"Oblivion Six Five Six, Poncahonca Center, are you declaring an emergency? Say intentions."

"Poncahonca Center, Oblivion Six Five Six, negative emergency. I wouldn't really know what to call it. Didn't make any difference at all, really, other than a lot of scales and dust blowing about in the aft cabin, and all our kleenex is gone. We were unaware that moths could scream, but apparently..."


While verification that the foregoing information is exact cannot reliably be made, the names and dates have been changed and removed to protect those who might otherwise die of embarassment.

 

[minitour]

I have no idea what you just typed, av....but it sounded cool

 

[Vector4fun]

And to think, some poor fools think they have to smoke pot to be that creative...


Avbug, that stuff burning on your last drop, those were pine trees weren't they???

 

[ATCER]

I can't answer on domestic non-radar but oceanic (North Atlantic and Caribbean) I can give you a lot of details.

In the Carribean (WATRS airspace, all non-radar) deviations are a common occurrence. In this airspace over 90% of A/C are on a route... they typically advise ATC that there is wx say 100 miles ahead, they request deviation 30 miles east of course, some say when they can return to course, most do not. If this is the first deviation on an airway we typcially will clear the A/C (depending on traffic) on the deviation and advise to report back on course. That report typically tells us where the wx ends... we then file a pirep to the wx office and can plan for furture deviations.

If we are unable to clear the A/C we give the pilot options, say West instead of East, maybe a decent or climb to an altitude, and ask pilot to advise intentions. Sometimes they accept the options, other times they declare an emergency or Captains authority and do what they want. In those situations we advise them of traffic and notify the supervisor. Paperwork and a record of what happened is recorded.

I would strongly advise against just deviating on your own... yes, I agree that often we will not have any idea BUT ! ... our offshore radars can see out a lot farther then many pilots think. Many have been surprised when visting the center what we can really see. Plus the military can see VERY FAR OUT ! ... they have flight plans and can see if A/C are off course. In the last few years I know of one Captain of a major US airline who was fired over a deviation, he went over 50 miles off course without saying word, he violated another sectors airspace and violated an active military block. If it was just an FAA violation I think he might have been able to hang onto his job but the military made a major issue of it.

Our hands are tied at times, if there is traffic we can't legally clear you on your request. We also understand that you have to do what you need to do... The further ahead you plan and request the deviation the better we can give you options.

One thing I have noticed ... AAL deviates like no one else... where other companies go 5 or 10 miles, or nothing at all, AAL will go 40 - 50 miles easy. I have always assumed it is some comapny reg.

 

[apcooper]

ATCER,


Good to hear from you. I am relieved to have read from you that pilots can now visit ATC facilites again. Send me a PM and maybe we can set something up since I'm not too far from JFK. I have a lot of ATC questions and find it one of the most facinating, important and sophisticated systems in all of aviation.


In the WATRS airspace you reffered to what are the dimentions both laterally and vertically? When you were giving examples of legacy carriers and WX deviations, I'm assuming these are flights on a North/South track from the NE corridor to PR, Jamica, USVI, etc.

 

[ATCER]

I would have to look up the exact figures for the dimensions of WATRS airspace... it's roughly from 300 miles or so offshore out to 60W and as far south as 23N. We own from 050 all the way up to FL600, some places we own as low 2500' ... all controlled airspace, that has gotten some pilots in trouble who tried to fly VFR not realizing that you would have to be below those alt's to be legal VFR.

The center is not near JFK... we are about 40-50 miles east on Long Island. I'm not sure of the tour status, there have been some security issues of late... I am not home at the moment but when I get home I will PM you a # you can contact to inquire about a tour. Do you work for a carrier ???

Your assumption of North South traffic to those destinations is correct... we work all that traffic (MKJS, TJSJ, TNCM, TIST, etc.) and also handle a large amount of the traffic transitioning to and from the North Atlantic serving points between the US and Europe and Africa.