View Full Version : NAT weather deviation...how far?

28th Jul 2002, 22:18
The weather on the tracks has not been a factor since the change in weather deviation procedures back in May.

The other day on Track Z it was necessary to deviate.

How do you read the new rules? If I do not want to bother calling Oceanic for deviation clearance, how far can I go? (I also do not want to turn all my lights on and call on 121.5).

31st Jul 2002, 22:49
I THINK you have to call if you deviate more than 10 miles, but am probably wrong!

1st Aug 2002, 06:05
I can only speak of the North Pacific. It may well be different on the North Atlantic.

If you need to deviate for weather you should always call ATC for clearance to do so.

If you need to deviate but CANNOT cannot contact ATC for clearance then you can deviate up to 10 miles left or right of track and still maintain your level. You must of course switch on all lights and infrom other traffic on 121.5 and the chat frequency of of your action. TCAS should also be carefully monitored.

If you need to deviate more than 10 miles but CANNOT conatact ATC for clearance to do so you should maintain your level until 10 miles from track and then climb / descend 300feet when greater than 10 miles from track. The requirement to climb or descend depends on your track and whether you are deviating left or right of track.

9th Aug 2002, 02:59
For what it's worth, I asked our Ops Specs folks about this. They spoke with their contacts at both Gander and Shanwick who advised they consider anything more than 2nm off the tracks a track deviation. They advised they expect one to call for such a weather deviation that would exceed 2nm off track. In the event one is unable to contact Oceanic, the table on the A/T chart applies.

Nobody is going to go through a CB in an effort to maintain track integrity. However, Gander/Shanwick expect that while deviating without a clearance (exercising Pilot-in-Command authority) one would continue to make an effort to contact Oceanic.