He did get on a plane, but without the explosive device.

It was a deeply embarrassing, farcical episode where a security supervisor identified a suspicious object in a passenger's bag and questioned the passenger. She then confiscated the item, popping it in her pocket for safe-keeping, intending to have a good look at it later. The passenger was free to travel, but with all the fuss had missed his (Ryanair) flight. But he was back at the airport a couple of days' later and resumed his trip to Italy.

While he was away the Manchester team looked at the item again, got suspicious and handed it over to specialists for examination: they pronounced it a viable explosive device. The passenger was arrested when he returned to the UK.