Officials at Manchester Airport in northern England have suspended a security guard for failing to notice a "fake bomb" in a passenger's hand luggage, the Manchester Evening News reported.
Transport authorities had deliberately planted the device to check whether safety procedures were properly followed. They were not.
The pretend explosives, which the Evening News said were "designed to clearly look like a bomb," were cleared for take-off despite passing through the airport's scanners.
The security officer who should have spotted them was reportedly absorbed in checking her work rota at the time.
She has since been suspended and an investigation launched.
The UK's Department for Transport told the BBC that it regularly carried out inspections at all of the country's airports. Some are covert, involving officials posing as passengers or even flight attendants to test security procedures.
(NB: Airports tend to take less kindly to anyone else pretending to have a bomb. One man got himself a conviction for tweeting that he would blow another British airport "sky high" when it was closed due to snow; the verdict was later overturned.)
More from GlobalPost: Man falls asleep on baggage belt, and other embarrassing security breaches
Manchester, by the way, is the same airport that allowed an 11-year-old boy to board a plane for Rome without either a passport or a ticket. That incident, just days before the opening of the London Olympics in July, prompted the British Transport Secretary to order several high-level investigations.
But Manchester officials can take comfort, even if passengers can't, from the knowledge that they're not alone in occasionally letting the wrong things onto planes. Other notable lapses in airport security include a chef taking four kitchen knives onto a flight from Chicago O'Hare, and a woman sneaking her pistol onto a plane at Dallas-Fort Worth.
Meanwhile other TSA agents face criticism for being a little too zealous. Apart from the ones who allegedly allowed drugs through security for cash, that is.
More from GlobalPost: Man with "world's biggest penis gets stopped by TSA agents