GPS to be jammed
A MoD exercise will intentionally interfere with GPS signals in north Scotland.
Exercise JOINT WARRIOR will see periods of GPS jamming taking place from two locations - Loch Ewe and Faraid Head - at various times between 6 and 14 April.
Depending on height, the jamming could affect receivers out to ranges of between 10 and 145 NM.
The CAA warns that, although GPS equipment is an accepted means of compliance with basic and precision area navigation (B-RNAV and P-RNAV), one of the conditions of its use is that an aircraft must carry equipment to allow reversionary means of navigation - and should not rely on GPS for such operations in the affected areas.
It adds that, for IFR operations, only radio navigation equipment required by the rules for IFR operations should be used. And for VFR, conventional means of navigation - including DR - should always be used. Operators should be prepared for erroneous readings if cross-checking with GPS in the area affected by the jamming.
The jamming will also have some affect on sea- and land-based GPS receivers - but only in comparatively limited areas.
Further jamming will be conducted for up to 3 days in the period 10-21 July - in this case with jamming aircraft orbiting at 10,000 ft along a 50 NM track of 270°T from Kirkwall, starting 10 NM and ending 60 NM to the W of Kirkwall.
MoD states that 'jamming is likely to affect civilian Standard Positioning Service (SPS) receivers over a large area'.
See NATS Aeronautical Information Circular (AIC) below for April details.