And the tornado adv went into service before the radar was ready to be fitted, so the first squadrons had concrete blocks of equivalent weight in the nose. Thi

And the tornado adv went into service before the radar was ready to be fitted, so the first squadrons had concrete blocks of equivalent weight in the nose. This was mockingly dubbed "blue circle" after the "rainbow" code-naming convention and the well-known cement company. Luckily the Russians didn't come.