Remember that big NAT military exercise a couple of years ago? Formidable Shield is happening again now, which will mean parts of North Atlantic airspace will be closed to flights for several hours at a time.
There are daily closures in the EGD701 area off the coast of Scotland until May 23, but the big one to watch out for is a large closure of airspace across the northern half of the EGGX/Shanwick FIR on May 20 between 15-21z (with May 22 as the backup day).
The map below shows everything we know about this so far, taken from this UK SUP.

For the big closure on May 20, ATC might start rerouting flights before the airspace closure starts (15z) with the use of Flight Plan Buffer Zones extending 30 NM or 60 NM beyond the closed airspace.
There’s no timings yet for when these might be activated, and ATC have said they won’t make any decision on this until nearer the time when they know where the jet stream is going to be and what the tracks might look like, but best advice would be plan a flight that clears the area at least 1 hour before the airspace closure (so 14z).
Keep an eye on the EGGX/Shanwick Notams – they will publish one for the big closure at least 24 hours prior, which will look a bit like this (except it will say EGD2FS25 instead of EGD1FS25).

And for any questions on Formidable Shield, you can contact the UK Airspace Management Cell at SWK-MAMC-ManagedAirspace@mod.gov.uk.
More on the topic:
- More: Gander’s Bringing Back CPDLC Oceanic Reroutes
- More: 2026 North Atlantic Plotting & Planning Chart
- More: NAT Guide 2026 – My First NAT Flight is Tomorrow
- More: Timeline of North Atlantic Changes
- More: NAT CPDLC Route Uplinks: Crew Confusion and Errors
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