A Cold War era US military plane - dubbed the Flying Pentagon and able to withstand a nuclear blast - has been spotted flying over the UK.
The Nightwatch command-and-control Boeing 747 E4-B aircraft is one of a fleet kept in service by Washington since the 1970s to act as an airborne base for top brass in the event of a nuclear war.
Capable of staying in the air for days, the huge plane is designed to withstand the electromagnetic pulse from a nuclear blast and conducts routine training and readiness missions with at least one kept on 24/7 readiness.
