By Anshuman Daga and Siva Govindasamy
SINGAPORE/KUALA LUMPUR, July 23 (Reuters) - Singapore's civil aviation authority has asked airlines based in the city-state to review their risk assessment of conflict zones following the shooting down of a Malaysia Airlines jetliner over Ukraine last week.
The deaths of nearly 300 passengers and crew in the downing of Flight MH17 have shocked the aviation industry and prompted calls for a re-think on assessing the threat to planes flying thousands of metres above fighting on the ground.
Before the shooting down of the jet, which Western governments have blamed on Russian-backed separatists, the flight path it was following across eastern Ukraine was heavily used by airlines plying busy routes between Europe and Asia.
Singapore Airlines Ltd (SIA) was one of the heaviest users of the route in the week before the crash, along with other international carriers such as Lufthansa, Thai Airways, Qatar Airways and KLM.
"We note that following the MH17 incident, SIA had immediately re-routed their flights to avoid Ukrainian airspace," said the Civil Aviation Authority of Singapore (CAAS) in an emailed response to questions from Reuters.
"CAAS has also since asked Singapore carriers to review their risk assessment on conflict areas."
NO GLOBAL AGENCY
Singapore's Changi Airport is a major hub for East-West air travel, and low cost carriers Tiger Airways, SIA's Scoot and Jetstar Asia, a budget arm of Qantas Airways, are also based in the city-state.
In the days since the MH17 tragedy, flight tracking websites have shown the once-busy skies over eastern Ukraine empty of traffic, while aircraft crowd along routes across Turkey and the Black Sea to the south.
In a response to a letter in the Straits Times newspaper on Wednesday, Singapore Airlines senior vice president of flight operations Gerard Yeap said the airline had avoided Ukrainian airspace entirely since the disaster.
"There are several other parts of the world that we proactively avoid flying through, even though they are available for use," he said. "This has long been our practice, and is the result of our continual assessment of advisories from the national authorities and aviation bodies."
No single global body has overall responsibility for keeping the skies safe for civil aviation.
Ultimately it is up to individual nations to decide whether a threat exists and, if necessary close their airspace, although national civil aviation authorities can ban their domestic carriers from jurisdictions they consider unsafe.
"The industry has been operating on a system that had successfully worked for decades and which we honestly and genuinely believed was robust because years had proved it to be so," said the chief executive of an Asian carrier who declined to be identified due to the sensitivity of the matter.