A source with the London City Airport said the pilot became angry while going through procedures at the hub's downstairs security gate, which isn't accessible by the public, The Sun reported Wednesday.
"The pilot was asked to take off his shoes and belt like everyone -- but completely lost the plot," the source said. "He pulled down his trousers and pants to completely expose himself, then turned to the security guard and asked angrily, 'Do you want to search this?'"
The pilot's flight was canceled and 37 passengers waited two hours for a new flight. Police questioned the pilot but he wasn't arrested.
"All pilots have to go through these procedures so no one can understand why he reacted the way he did. Perhaps he was having a bad day," the source told The Sun.