A Ministry of Defence electronic warfare exercise near Sennybridge is currently causing temporary disruptions to satellite navigation systems across parts of mid and south Wales.

The exercise, known as “Rock Lobster,” involves deliberate radio frequency jamming targeting Global Navigation Satellite Systems (GNSS) such as GPS, as well as drone command and control signals. The jamming activity is taking place daily between 8am and 5pm until Friday, June 20, within a 5-kilometre radius of the MoD’s Sennybridge training area.

The interference, coordinated by the Civil Aviation Authority (CAA), may affects not only aircraft navigation but also ground vehicles and drones that rely on satellite signals. GNSS disruptions are expected at altitudes up to 40,000 feet - an elevation regularly used by commercial airliners - with a coverage area extending across much of mid Wales and reaching as far south as Devon and Cornwall.

Aircraft operators are reminded to comply with regulations requiring backup navigation equipment and be prepared to switch to conventional navigation methods such as radio beacons, map reading, and dead reckoning during this period. Visual flight rules (VFR) pilots in particular should exercise caution and plan accordingly.

Air Navigation Service Providers have been alerted and are on standby to assist pilots experiencing GPS signal degradation within the affected airspace.

For residents and local drone operators, the CAA advises awareness that some electronic devices may be temporarily impacted by the jamming activity.

For more information or urgent concerns during the exercise, the CAA has set up dedicated contact numbers reachable at Sennybridge Operations on 01874-635599 and the Trial Manager on 01980-951989.