RLatSM on NAT Tracks

[Mike Oxbig]

A bit of help from our ATC colleagues please. I have been reading NATS Ops Bulletin 2015-003 about reduced lateral separation minima in the NAT Tracks and it's implementation in Nov 2015. With the separation being reduced to ½ degree/25nm on designated tracks, I can't see any change to the contingency procedures to reflect that. It seems as if one should still turn 45 degrees left to right and offset 15nm before descending.

I fly a Gulfstream on random routes usually above the NAT (FL430/450) and was wondering if the contingency procedure, should I have to descend through those designated routes, remains the same and also if operators that are cleared for RLatSM have received any updates should they have to descend.

Any help with a reference would be very useful - I have looked at the 'NORTH ATLANTIC OPERATIONS AND AIRSPACE MANUAL' but that still states as above.

Thanks.

[rab-k]

Procedures are not yet published so can't provide a reference I'm afraid. Come back in October and there may be something in print to which we can refer to.

[Mike Oxbig]

Thanks for that. 'I'll be back'!!

[Roger That]

Expect these to remain unchanged Mike.

Have a look at PANS ATM (ICAO Doc4444) 15.2 ‘Contingencies in Oceanic Airspace’ . and 15.2.3 ‘Weather deviation procedures' for the detail.

I believe that a 'Special Emphasis Item' Ops Bullitin will be published shortly that will summarise some items that's intended to compliment the NAT Ops Bulletin you refer to.

If you need more, PM me.

[rab-k]

FYI...


Reduced Lateral Separation Minima within the North Atlantic - NATS (http://www.nats.aero/rlat/)

[kcockayne]

Just an innocent, & genuine, question - might be naive, too ! how does half a degree of latitude equate to 25nm ? Surely half a degree is 30 nam, or have I missed something ?

[2 sheds]

The half-degree is just the practical application of the declared 25 nm minimum.

2 s

[kcockayne]

Thanks, 2 Sheds. I should have realized that !

[DaveReidUK]

Just an innocent, & genuine, question - might be naive, too ! how does half a degree of latitude equate to 25nm ? Surely half a degree is 30 nam, or have I missed something ?

Half a degree of latitude between tracks only equates to 30nm separation if they are aligned due east-west. :O

[Take up the Hold]

I think the 25nm will be to allow offset flying due to weather. 30nm will be the normal separation between tracks.

TUTH