NAT/MNPSA Ops.

[C152R]

I have asked this question a number of times and am hoping an ATCO can provide an answer, with a text reference if possible.

1. Random Routes flown over the Atlantic. Are these routes a series of pre determined way points designed by ATC which are not part of the NAT track system or are they any series of way points that can be selected by an operator which is not part of the NAT tracks.

2. Regarding the requirement to establish a position 15nm from a NAT track in the case of an emergency, does that requirement also apply to a Random Track.

Thanks

C152

[galaxy flyer]

There are several references and someone, hopefully a NAT region ATCO, to link to them. But, random routes can be requested by the flight planner for the operator and can be any legit waypoints or lat/long coordinates in 10 degrees of longitude.

As to the 15nm offset for contingency situations, the crew must first align themselves with any tracks that are in use, them offset and descend. When the track system is active, most random routes are either above or below the established levels, typically FL310 thru FL 400, I think. I do most crossings above the system at FL 430- 470 and briefing and planning the descent is a normal procedure.

GF

[Bigears]

NAT Doc 007 Documents and also Doc 7030 Documents will be useful
Sorry, but bit late to go looking for exact pages

[mutt]

ICAO EUR/NAT Office

We file/fly random routes as Galaxy said on chosen Lat/Long, usually by requesting best route from Jeppesen flight planning system. We fly over the MNPS, we plot the current NAT tracks so we can plan an emergency descent aligned to the tracks but not on them.

Mutt

[C152R]

NAT/MNPSA

To clarify the question.
If one is flying within the vertical airspace ie. FL285 to FL420 lets say FL360 and the Random Track flown is North of TRACKA or South of TRACKZ and no part of the planned track is common to any NAT Track. Does one still need to offset 15nm before descending in case of an emergency.

Secondly to confirm If a Random Track is planned again without any part of the track being common to a NAT Track. This track is chosen normally by the operator and is not a track selected by ATC which is a system of Random Tracks.

These questions are specific and are not really answered in the documents.

Thanks

C152R

[BOAC]

Does one still need to offset 15nm before descending in case of an emergency.

- no. See Mutt's post 4. Your nav chart should have relevant existing nat tracks marked on it so that you descend as appropriate. As Mutt says, you need to finish up offset from existing tracks.

Re Q2: I believe it is company requested but I have had them 'modified' by ATC. There cannot really be a "system of Random Tracks", although there are inevitably 'favourite' routes that will cross the Nat Tracks.

[mutt]

If one is flying within the vertical airspace ie. FL285 to FL420 lets say FL360 and the Random Track flown is North of TRACKA or South of TRACKZ and no part of the planned track is common to any NAT Track. Does one still need to offset 15nm before descending in case of an emergency.

12.3 SPECIAL PROCEDURES
12.3.1 The general concept of these Oceanic in-flight contingency procedures is, whenever operationally feasible, to offset from the assigned route by 15 NM and climb or descend to a level which differs from those normally used by 500 ft if below FL410 or by 1000 ft if above FL410.

Secondly to confirm If a Random Track is planned again without any part of the track being common to a NAT Track. This track is chosen normally by the operator and is not a track selected by ATC which is a system of Random Tracks.

4.1.6 Outside of the OTS periods operators may flight plan any random routing, except that during a period of one hour prior to each OTS period the following restrictions apply:

not really answered in the documents.

Actually they were answered from the official documents

Mutt

[BOAC]

C152 - you may find this (Doc 7030 extract) of use regarding an emergency descent from a random track. (My bold and see reference to 'organised tracks' eg Nat Tracks). It would be foolish to merely offset 15nm from the random track and then steam blissfully across all the others

9.1.1.1.2 An aircraft compelled to make a descent through MNPS airspace, whether continuing to destination or turning back, should, if its descent will conflict with an organized track:
a) plan to descend to a level below FL 280;
b) prior to passing FL 410, proceed to a point midway between a convenient pair of organized tracks prior to entering that track system from above;
c) while descending between FL 410 and FL 280, maintain a track that is midway between and parallel with the organized tracks; and
d) contact ATC as soon as practicable and request a revised ATC clearance.

As we say, it depends on knowing where you are and they are

I think you will find Mutt's ref should read 13.3.1 in 007

[rab-k]

Some people are way out of date re. Oceanic procedures and others are simply wrong!

C152R (and others) I suggest you:

Follow this link to ICAO Doc4444 Amendment 2 and see 15.2 "Special Procedures for in-flight contingencies in Oceanic airspace" Also suggest you look at 16.5 "Strategic lateral offset procedures (SLOP)"

Follow this link to CAA CAP694 and see Chapter 9 "Special Procedures - Shanwick Oceanic Control Area (North Atlantic Region - NAT)"

Follow this link to NAT Regional Supplementary Procedures (SUPPS) (Doc7030) which should provide answers to more general questions.

Come back if you're unsure of anything, having read the above, as I may be able to help.

RK
(EGGX ATCO)

[mutt]

rab-k

Some people are way out of date re. Oceanic procedures and others are simply wrong!

Would you be so kind as to educate us about any errors that we have posted?


Mutt

[BOAC]

,,,,,,,or, more usefully, just answer the questions?

[rab-k]

When the track system is active, most random routes are either above or below the established levels

On an averge day the numbers of randoms routing above or below the OTS number two dozen max. However, as much as 25% of overall traffic can be on random routes, between 310/410 inclusive, outside (north or south) of the OTS. Particularly if the forecast WX changes significantly from the time the OTS is designed and published to when operators submit a FPL. LIDO/CIRRUS or equivalent systems will get a weather update post track publication and operators may well determine that a random route is more cost effective than any particular organised track. Given that a busy 24hr period can see 1400+ flights crossing the pond the numbers of random flights either side of the OTS can be significant; those above or below the OTS less so.

Does one still need to offset 15nm before descending in case of an emergency.

- no. See Mutt's post 4.

You are required to offset 15 irrespective of flying on a published OTS or random route. Doc4444 15.2.2.3 states:

"Specifically, the pilot shall:

a) Leave the assigned route or track by initially turning at least 45 degrees to the right or left, in order to acquire a same or opposite direction track offset 15 NM (28 km) from the assigned track centerline. When possible, the direction of turn should be determined by by the position of the aircraft relative to any organized route or track system."

In addition, the SUPPS to Doc7030 state:

"9.1.1.1 Descent through the MNPS airspace

9.1.1.1.1 An aircraft that is not MNPS/RVSM-approved and is unable to maintain a flight level above MNPS/RVSM airspace should descend to a flight level below MNPS/RVSM airspace".

- going on, with regard only to those above F420 who do not have MNPS/RVSM approval, infringing the OTS during an emergency descent, to state:

9.1.1.1.2 An aircraft compelled to make a descent through MNPS airspace, whether continuing to destination or turning back, should, if its descent will conflict with an organized track:
a) plan to descend to a level below FL 280;
b) prior to passing FL 410, proceed to a point midway between a convenient pair of organized tracks prior to entering that track system from above;
c) while descending between FL 410 and FL 280, maintain a track that is midway between and parallel with the organized tracks; and
d) contact ATC as soon as practicable and request a revised ATC clearance.

The OP was referring to levels within MNPS:

If one is flying within the vertical airspace ie. FL285 to FL420 lets say FL360

To quote 9.1.1.1.2 whose procedures only apply to those operating above F420 without MNPS/RVSM approval, conducting an emergency descent through the OTS, when the OP seeks info for procedures applicable to F360, may be somewhat misleading.

We have had, (most recently from crew operating EINN - CYQX), telephone calls to our desk from biz jet crews who don't regularly jump the pond and who have apparently been provided with way out of date procedures or worse, none at all. However, asking for info re. procedures on sites like this has its risks - better just to provide the links, as per Bigears, and let the OP do the rest IMHO.

[rab-k]

However...

I have asked this question a number of times and am hoping an ATCO can provide an answer, with a text reference if possible.

1. Random Routes flown over the Atlantic. Are these routes a series of pre determined way points designed by ATC which are not part of the NAT track system or are they any series of way points that can be selected by an operator which is not part of the NAT tracks.

2. Regarding the requirement to establish a position 15nm from a NAT track in the case of an emergency, does that requirement also apply to a Random Track.

1. A random route is any series of way points selected by an operator which do not correspond exactly to the (entire) route and level(s) of a published track.

2. Yes.

If one is flying within the vertical airspace ie. FL285 to FL420 lets say FL360 and the Random Track flown is North of TRACKA or South of TRACKZ and no part of the planned track is common to any NAT Track. Does one still need to offset 15nm before descending in case of an emergency.

Secondly to confirm If a Random Track is planned again without any part of the track being common to a NAT Track. This track is chosen normally by the operator and is not a track selected by ATC which is a system of Random Tracks.

Firstly: Yes

Secondly: All routes are chosen by the operator for FPL purposes; whether they are wholly on a published track at a published level, they partially infringe a track at a published level, or they remain clear of the OTS at the published OTS levels.

However, ATC will issue an Oceanic Clearance on the basis of traffic already cleared, predicted traffic volume, airspace restrictions, and any route restrictions/requirements between ATSUs which operators may/may not be aware of on the day in question. Any of these may result in the route specified in the Oceanic Clearance differing from that of the FPL. The basic FPL requirements are outlined in the CAA ref in my first post.

[mutt]

However, asking for info re. procedures on sites like this has its risks

So true...... especially as you have quoted...

c) while descending between FL 410 and FL 280, maintain a track that is midway between and parallel with the organized tracks; and

Unfortunately I can't find find a reference to that procedure in the GUIDANCE CONCERNING AIR NAVIGATION IN AND ABOVE THE NORTH ATLANTIC MNPS AIRSPACE Edition 2010 and this is dated later than your reference....
NAT Regional Supplementary Procedures (SUPPS) (Doc 7030) Working Copy – 5th Edition - 2008

So which are we supposed to follow?

Mutt

[rab-k]

BOAC had in fact quoted the following:

9.1.1.1.2 An aircraft compelled to make a descent through MNPS airspace, whether continuing to destination or turning back, should, if its descent will conflict with an organized track:
a) plan to descend to a level below FL 280;
b) prior to passing FL 410, proceed to a point midway between a convenient pair of organized tracks prior to entering that track system from above;
c) while descending between FL 410 and FL 280, maintain a track that is midway between and parallel with the organized tracks; and
d) contact ATC as soon as practicable and request a revised ATC clearance.

...from a document Bigears had linked to earlier:

"NAT Regional Supplementary Procedures (SUPPS) (Doc 7030) Working Copy – 5th Edition - 2008

This version of the Working Copy of the 5th Edition of the NAT Regional Supplementary Procedures (SUPPS) (Doc 7030), Amendment No. 3, dated 15 October 2010, includes the following approved amendment(s) which have not yet been published."

My point re. the above was that it was not relevant to the scenario outlined by the OP.

The document you refer to, "GUIDANCE CONCERNING AIR NAVIGATION IN AND ABOVE THE NORTH ATLANTIC MNPS AIRSPACE Edition 2010", was last updated on 17th October 2011, (link here), however, according to the ICAO webpage linked to above, the SUPPS were last updated on 4th July 2011. You be the judge.

For my part, allow me to misquote Kiefer Sutherland: I have two books at my bedside, the MATS Part 2 and the King James Bible. The only proper authorities I am aware of are my Local Area Supervisor and the Lord our God.

The (SUPPS) non MNPS/RVSM descent through OTS does not make any appearance in our current MATS Pt 2; which is good until 2nd December 2011.

[mutt]

17th October 2011

Thank you for the update.

Mutt

[rab-k]

You're welcome. Doesn't help much given the 2011 edition still lacks any reference to the procedure which appears in the SUPPS to Doc7030. The wheels of ICAO grind slowly...

[mutt]

It appears that these 2 sources of information contradict each other regarding contingencies, MNPS guidance states to go 15 nms offset, while Doc 7030 states to go midway between two tracks which is 30nms!

If i hadnt gotten into this discussion I wouldnt even know that the Doc 7030 etc existed as they were never mentioned by our training provider in either Dubai or the USA, so please dont be surprised that crews don't totally understand what you expect them to do

Mutt

[BOAC]

..........and still, despite the plethora of links - some 'yet to be published', C152 still does not know what to do after setting up a perfect 15nm offset from his/her random track. What an a/c descending through MPNS airspace from above 420 should do should be no different to what an a/c starting at 360 should do, surely? Perhaps you can quote that procedure for the OP from the bedside book? Personally I would weigh the odds against hitting the traffic coming the other way below me exactly on my random track against sailing blithely (offset 15) downwards through several established tracks definitely full of metal. My bedside reading says more important to put myself between and parallel to fixed tracks than to simply fly an immaculate 15nm offset on my random track. My choice, I reckon, since they are my passengers.

[rab-k]

It appears that these 2 sources of information contradict each other regarding contingencies, MNPS guidance states to go 15 nms offset, while Doc 7030 states to go midway between two tracks which is 30nms!

On the face of it yes, but my own take on this is that they don't necessarily contradict, but in addition to the standard 15 NM offset and descent, further consideration should be given by crews of non-MNPS/RVSM aircraft in relation to descending through the OTS from F430+ to F280-. Put simply, everyone does a 15NM offset as standard, but in the event that you're non-MNPS/RVSM descending through tracks from F430+ you should also consider going for the mid-point from F410 on down. Again, and I stress, my own interpretation.

so please dont be surprised that crews don't totally understand what you expect them to do

To be honest, I'm not sure how much weight to place on the SUPPS either, given that certain elements fail to appear in either the 007/4444/MATS 2, but they're out there for all to see and I did suggest it "should provide answers to more general questions." Until I'm told otherwise I'll stick to the MATS 2; whose wording is extracted from Doc007 Chapter 13.

What an a/c descending through MNPS airspace from above 420 should do should be no different to what an a/c starting at 360 should do, surely?

Traffic at F360 is within MNPS airspace and is therefore MNPS certified; having all the benefits of reduced lateral/longitudinal separation. Non-MNPS traffic above F420 does not have the required Nav capability/accuracy/redundancy to enjoy the reduced MNPS separation and must therefore be treated differently from those who are MNPS certified. (Lateral separation for example is increased to 120 NM as opposed to the 60 NM for those having MNPS certification). I assume that is what those at ICAO were considering when they advise non-MNPS to go for the mid-point (currently placing an a/c 30NM from the adjacent tracks).

My bedside reading says more important to put myself between and parallel to fixed tracks than to simply fly an immaculate 15nm offset on my random track.

Couldn't agree more, but what you're suggesting doesn't (yet) appear in the 007/4444/MATS 2 and only appears to exist in a "working document" (SUPPS); suggesting to me that whilst not in the documents mentioned, it should be a consideration for crews of non-MNPS/RVSM descending through OTS.

I imagine that discussions elsewhere precisely along these lines have resulted in the appearance in the SUPPS of such. As I see it the issue, other than not appearing where you would expect/hope to find it, is that going for the mid-point is equally as sensible for MNPS certified as it is non-MNPS certified when descending from a position directly above the OTS to a position below. (The advantage for MNPS certified a/c having to go for only a 15NM offset is that a descent could possibly commence earlier than might otherwise be the case if having to delay until reaching the midpoint).