AVIATION officials have launched an investigation after the pilot of a jumbo jet had to abort a landing seconds before touchdown at Kai Tak when a light aircraft strayed on to the runway. The Qantas Boeing 747-200, carrying about 300 passengers on flight QF027 from Sydney, was half way through a right-hand approach turn over Kowloon when it suddenly increased power and climbed. An investigation into why the Hong Kong Aviation Club Cessna 172 had strayed into the jumbo's landing path is being carried out by the Civil Aviation Department following the incident at 5.10 pm on Saturday. The jumbo, an earlier model to the China Airlines' jet currently floating in Victoria Harbour, was able to land after circling the airport. Passenger Bradley Perrett, on his first flight to Hong Kong, said he felt the plane suddenly increase thrust and saw the flaps go up. ''We were into the right hand turn when we suddenly pulled away,'' he said. ''The first officer came on [the intercom] and said a light aircraft which had been ordered to wait until we had landed had strayed on to the runway.'' Twelve days ago, a Boeing 747-400 skidded off the end of the runway while trying to land in poor visibility during a severe tropical storm. Mr Perrett said he wondered what the outcome might have been had bad weather on Saturday prevented the Qantas pilot from seeing the Cessna until it was too late. Acting Air Traffic General Manager at Kai Tak, Albert Lam Kwong-yu, said an investigation had been launched into the cause of the near catastrophe. ''The light aircraft had been ordered [by air traffic control] to move to a holding point but entered the runway,'' he said. ''It is routine to find out why something like this happened.'' The investigation will determine whether the pilot of the Cessna or air traffic control was at fault. Mr Lam said at this stage it appeared the pilot of the four-seater Cessna, who he refused to name, had been given the correct instructions. Qantas regional director Alan Loke said he was unaware of the incident. ''The pilot would make a report following an incident like this but it would be sent directly to Sydney,'' he said. Paul Clift, of the Hong Kong Aviation Club, said the club would be carrying out its own investigation into the incident. ''One of our aircraft did overshoot on to the runway,'' he said. ''We will be holding our own in-house investigation.'' Hong Kong Aviation Club is the only private club to use Kai Tak. The only other small aircraft using the airport belongs to the Government Flying Services. Two weeks ago a controversial air traffic system which had operated at Kai Tak for more than 20 years was abandoned to improve safety. The ''opposite runway'' system, in which an aircraft takes off over the sea and climbs in a staggered path directly into an oncoming plane, was dropped. The acting director of Civil Aviation was due to meet members of the Liberal Democratic Foundation to discuss the system today.