KARACHI, Nov 22: A PIA 747 aircraft had spilled around 60 ton fuel over the Arabian Sea not very far from the coast on Friday last, Nov 15, which might have killed a large number of fish that were washed ashore on the city’s Seaview beach a few days ago, it is learnt.

According to the sources, the airliner was proceeding to London but after it covered some distance it developed some fault and had to return to the Quaid- i-Azam International Airport. Before landing on the runway it had to get rid of its excess fuel. The aircraft emptied its fuel tanks while flying at an altitude of 4,000-5,000 feet.

The sources said the air traffic controlling agencies, keeping such situations in mind, had designated an area in and around Thatta district only where airliners in emergency situations could spill their excess fuel before landing at the Karachi airport.

The sources said another condition in this connection was that aircraft should be flying at least at a height of 20,000 feet at the time of spilling excess fuel so that the major quantity of the fuel, which contained many toxic compounds, including volatile ones, could evaporate before reaching the ground or sea. This was to ensure that the recipient surface was comparatively less affected by the adverse effects of the oil.

The sources said besides having hazardous effects the oil also formed a film on the water surface due to which it acted like a blanket. No oxygen passed through this film due to which submarine living organisms suffocated and died.

The sources added that after a day or two another aircraft of the national airline that was returning from England also had to spill its fuel soon after taking off from London. But it followed the rules and spilled its excess fuel at the designated area specified by the air traffic controlling agencies of England.

Responding to Dawn queries, a senior PIA officer, who asked not to be named, said a 747 Combi aircraft of the national carrier, designated as flight PK 787, flew from Karachi for London on Nov 15. He said after flying for around a couple of hours the aircraft developed some fault and it had to return to Karachi.

The officer said before landing at the Karachi airport the aircraft spilled its fuel, which was very little in quantity, away from the city in the sea while flying at a high altitude. He claimed that since the aircraft was flying at a high altitude, most of the spilled oil would have had evaporated.