Pakistan's national carrier is investigating how a major safety breach was made aboard one of its international flights last month, when seven passengers spent a four-hour flight standing in the plane's aisles.

The Dawn newspaper reported on Saturday that Pakistan International Airlines (PIA) flight PK-743 carried 416 passengers on a flight from Karachi to the Saudi city of Medina on January 20, despite having a capacity of 409 including jump seats.

"Our CEO ordered the investigation into this incident soon after details emerged, which was much earlier than it was reported in the media," Danyal Gilani, PIA's spokesman, told Al Jazeera.

Soon after the incident was reported, Anwer Adil, the flight's captain, released a statement denying any wrongdoing on his part and said that by the time he was informed about the extra passengers, the plane had already taken off.

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"After takeoff, when I came out of the cockpit, the senior purser informed me that there were some extra people who were boarded by traffic staff," Adil was quoted as saying.

"I also noticed that some of them were people whom I had categorically refused jump seats at the check-in counter before the flight when they approached me for grant of the jump seat."

Adil said that since the plane had already taken off, returning to the airport to offload the extra passengers "was not possible as it required lot of fuel dumping, which was not in the interest of the airline".

Pilot blames purser

Adil went on to lay the blame on the senior purser by saying it was her responsibility "to ensure that the number of passengers tallied with the trim sheet [airline document] and that if there were any extra passengers, she should not have accepted them".



According to the Dawn report, the boarding passes issued to the extra passengers were handwritten and not computer generated, and did not tally with the official flight manifest.

An aviation safety and regulations handbook released by the US Federal Aviation Administration underlines the importance overloading an aircraft, whether with passengers or luggage.

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"The pilot should always be aware of the consequences of overloading. An overloaded aircraft may not be able to leave the ground, or if it does become airborne, it may exhibit unexpected and unusually poor flight characteristics," according to the handbook.



PIA's Gilani said he was unable to confirm the number of officials being probed or how long it would take to complete the investigation, but said the carrier will "punish anyone found guilty".

He said that this incident of overloading a plane was the first of its kind. However, the national airline has previously been accused of carrying two extra passengers in a plane's toilet over a domestic route.



Over the past few years, the Pakistani national carrier has incurred heavy losses, reportedly exceeding $3bn, prompting the government to discuss the option of privatising the airline despite protests from airline staff.