Malaysia has tightened its enforcement of rules on foreign aircraft, including those from Singapore, entering its airspace.
Operators of private flights have been reminded that they must apply for a permit, typically about a week before departure, sources said. If they do not and are caught, they could be detained and questioned by the authorities.
The ruling does not affect commercial carriers that fly to Malaysian cities, such as Singapore Airlines, Tigerair and Jetstar.
While the requirement for a permit is not new, it has never been strictly enforced, said a member of a flying club in Singapore who did not want to be named.
"The usual practice was to file a flight plan a few hours before the flight and that was fine. Nobody kicked up a fuss," he said.
Malaysia's move comes in the wake of an incident in October when an aircraft belonging to ST Aerospace was intercepted by Indonesian fighter jets. The plane, which was en route from Sibu in Sarawak to Seletar Airport, had a pilot instructor and two trainees on board.
It had allegedly entered Indonesian airspace without the necessary flight permits, but was reportedly intercepted while in Malaysian airspace.
ST Aerospace said at the time that the required approvals had been duly sought before the flight.
Malaysia's Department of Civil Aviation did not respond to queries when contacted but a senior official told The Straits Times: "I am very concerned about this issue, especially when foreign-registered aircraft stay longer than necessary in this country. There are also safety issues."
It is not known how many private flights operate from Singapore to Malaysia on a daily or weekly basis, but insiders said most are by ST Aerospace.
The rest are by flying clubs and associations such as the Republic of Singapore Flying Club and Seletar Flying Club, as well as owners of private planes.
An ST Aerospace spokesman noted regarding the recent development: "Our company has been filing flight permits in accordance with existing timeline requirements, and will make necessary adjustments to comply with any new regulation as required by the authorities."
The flying club member said: "There is no cost involved when applying for the permit, so that is not an issue, but the additional step will make the process a bit more troublesome.
"The other concern - and this would affect mainly leisure flight operators - is that it is not always possible to plan a flight a week in advance. Sometimes, you decide just a day or two before departure."
This article was first published on Dec 9, 2014.
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