Thank you for the link, very useful. Any other limks/references?
Thank you very much for your help!Uncle Google produced another hint, albeit the material is not free:
https://www.flightglobalimages.com/...rumman-rq-4-global-hawk-block-40-3783327.html
During a reconnaissance flight in Estonian airspace, the RQ-4B Global Hawk, a U.S. strategic surveillance drone, flew erratically and suffered from signal failure after Russian forces were able to attack electronically.
The Estonian Ministry of Defense said that Russian signal interference has larger ramifications in terms of military and civilian aviation in the Baltic region.