Rock is a confectionery made and sold in many of the UK's seaside holiday resorts. As the character Ida says in Graham Greene's novel Brighton Rock[?], "It's like those sticks of rock: bite it all the way down, you'll still read Brighton."
... work continued, aided by data from the British Aerospace EAP prototype which had first flown in 1986, and culminating in the first flight of the Typhoon prototype in 1994 ...