( dpa ) - An Australian-registered plane caused a 50- minute shutdown of Singapore's airspace to commercial aircraft while 16 flights circled, aviation officials said Thursday.
Two Australians were aboard the Cessna 208 Caravan float plane, which approached Tuesday night without an approved flight plan, prompting two Air Force F16 fighter jets to scramble during Changi Airport's busiest period.
The single-engine aircraft, which can land on water, began its flight from Thailand's Koh Samui island.
The Singapore Air Force tracked the plane as it flew toward the city-state. The two missile-armed fighters intercepted the Caravan and signalled the Australians to land at the central runway at 8pm, The Straits Times account of the incident said.
The two Australians were escorted away by police, who are investing the incident.
The plane was bought this month by Mary Cummins, who co-owns a tourist adventure flight company with Rhys Thomas, a former pilot with Australian airline Ansett, the newspaper said. The plane had previously been flown by an airline in Koh Samui.
Aviation experts said the air force has been operating an enhanced defence against airborne terrorists 24 hours a day since the September 11, 2001 attacks in the United States.
Altogether, the shutdown of commercial airspace affected 23 aircraft, disrupting flights in and out of Changi.
Thousands of dollars in fuel was lost as the airliners circled Singapore while awaiting permission to land.