A fire-control radar lock is one of the most threatening acts a military aircraft can take, as it signals a potential attack - often forcing the targeted aircraft to take evasive action.
The unit that has been using this vast, subterranean warren of war rooms, a dormitory, kitchen, canteen and makeshift gym as its headquarters since the summer is imminently relocating, so Sky News was invited inside.
The first stage of a ceasefire deal was agreed in October, but violence in Gaza has not stopped. On Saturday alone, seven people were reportedly killed.
The two sides said they had made progress on a security framework for post-war Ukraine, but said any "real progress toward any agreement" will depend "on Russia's readiness to show serious commitment to long-term peace."