A woman on a plane from Manchester to Islamabad mistakenly opened the emergency door, thinking it is the toilet.
The incident caused the flight to be delayed for seven hours after the woman sparked panic on the Pakistan International Airlines (PIA) flight.
"The PIA flight, PK 702, from Manchester to Islamabad was delayed by seven hours. The departure was delayed on Friday night when a passenger erroneously opened the emergency exit causing the emergency chute to activate," said a PIA spokesperson.
About 40 passengers had to be offloaded, along with their luggage.
The airline had to provide the passengers with transporation and hotel accommodation as well as booking them onto other flights.
An inquiry into the incident has been launched by PIA.