WHEN Governor Chris Patten addressed an international aviation conference in Hong Kong recently, he said there was nothing quite like flying in or out of Kai Tak Airport. ''There is no experience either quite like it for the 350,000 people living next to the airport or immediately under the noisiest parts of the flight path,'' he quipped. The reality of their plight is that, despite noise reduction techniques and curfews, they will have to put up with aircraft flying just above their heads every five minutes until Kai Tak closes and Chek Lap Kok takes over. The only certainty about when that'll happen is that it won't be before July 1, 1997. When it does, it will be the end of one of the world's great airports - an airport as unique as the city it sits slap bang in the middle of. Passengers the world over speak of the incredible sweep into Kowloon crowned by a final 42 degree right-hand turn which offers a close-up look at Hong Kong life - a glimpse into residents' front rooms. Then there is touch-down in Victoria Harbour, the runway invisible from passengers' seats until the last few seconds. Had it not been for a failed property venture by a Sir Kai Ho Kai and a Mr Au Tak back in the 1920s, there would never have been a ''Kai Tak''. As the Governor pointed out, it was perhaps the only case of a failed property venture in Hong Kong. In 1924, the Kai Tak Land Investment Company began reclaiming land in Kowloon Bay with the idea of creating a Garden City and recouping their money through the sale of houses. When buyers of plots proved too difficult to find, the company went bankrupt and the land reverted to the Government. With the need for an aircraft base in the territory, an aerodrome was opened on the site. On New Year's Day 1925, the first aircraft took off from its grass strip. And thus Kai Tak airport was born. The Royal Air Force (RAF) and the Hong Kong Flying Club moved on to the site during the next two years, and in 1928 the Government decided to develop the airport and build a concrete slipway for seaplanes and levelled the runway. Two years later a metal hangar was constructed by the fledgling Civil Aviation Department. The RAF's matt sheds were replaced by permanent buildings in the early 1930s and a control tower, hangar and office accommodation built in 1935. A year later the first passenger arrived on board an Imperial Airways four-engined de Haviland bi-plane from Penang, the first of a new weekly link which connected Hong Kong to Australia and Britain. Also in 1936, Air France began operating weekly flights from French Indo-China, China National Airways Corporation (CNAC) provided air-links with Shanghai and Guangdong and Pan-American Airways pioneered the first flight across the Pacific with regular scheduled flights beginning the following year, with the Hong Kong-Manila leg being flown by seaplane. As the RAF built up the number of aircraft stationed at the airport due to increasing tensions in Europe and the beginning of the Sino-Japanese war, a wireless station was established, floodlights for night landings installed and and a metrological service set up. In 1938, plans were drawn up for laying a 457-metre tarmac runway roughly in the same direction as the one which exists today. A year later a weigh-bridge was constructed and equipment for recording wind speeds introduced. The number of passengers passing through Kai Tak in 1938 was just below 10,000, nearly three times that of the year before. But war in Europe took its toll, and by November 1941, under the increasing threat of the Japanese, only CNAC was using the runway, its Pan American owners keeping open one weekly service to San Francisco. On December 8 the Japanese attacked the airfield with bombers and two days later the airport was abandoned. Most of the airport buildings were demolished, and the Kai Tak that stands today is testimony to the work of Prisoners of War who laid the foundations and built the first concrete runway. Today, Kai Tak is the third busiest international passenger airport in the world and second busiest international cargo airport. It lies in the middle of a city which is the eighth largest exporter in the world. Over the past decade passenger growth has been rising by more than 10 per cent each year. Last year alone 1.16 million tonnes of cargo and 23 million passengers passed through Kai Tak, all arriving or taking-off from the single runway built into the harbour in 1962 and later extended to 3,390 metres in 1974. The airport handled nearly 124,000 flights in 1993 and now is accessible to 57 airlines. But it has now reached its saturation point. Last year the Civil Aviation Department turned down a request for 6,700 flights because they could not be accommodated. Kai Tak is currently undergoing a process of fine-tuning to help it squeeze the maximum number of people through its gates. New parking bays have been created and can now accommodate 69 aircraft. The number of check-in desks are being increased, a new drop off area for passengers being constructed and another runway turn-off planned to clear traffic more quickly. Wider-bodied aircraft are being used to increase the number of passengers per flight and a new air traffic control system and computer baggage check-in system are being implemented. The acting airport general manager, Tony Norman, says working in such an environment is a tremendous challenge and a fantastic experience. ''What other airport is right in the middle of a city?'' he says. ''Kai Tak is unique, a wonderful place to fly into and a wonderful place to work.'' The reclamation around the airport has been phenomenal. About half the area of Kowloon peninsular has been reclaimed in Kowloon Bay since 1887, with hundreds of thousands of people now living within a stone's throw of the airport perimeter. Between 1962 and 1983 the Kowloon Bay reclamation gradually brought the eastern shoreline of the bay to within just a few metres of the runway. While this allowed for industrial and residential development to prosper, it also created a nullah and the Kwun Tong typhoon shelter, which is the final resting place for untreated waste from the surrounding area, creating a most unfortunate smell. One day, the noise and the smell and maybe even Kai Tak itself will be forgotten, the site to be covered by a new town as the whole of Kowloon Bay disappears beneath reclamation. Had people back in 1924 been a little more eager to buy Sir Kai Ho Kai and Mr Au Tak's lots, their families today could all be sitting on a fortune.