• Military aircraft are not required by international law to file flight plans with a country’s Air Traffic Service before flying through their Flight Information Region (FIR)
• Dr Ng made this point in response to questions from Workers’ Party MPs about an incident on May 31
• That day, Chinese planes had flown through Singapore's and Malaysia's FIR
• The Republic of Singapore Air Force had deemed that the flights were not a threat, Dr Ng said

SINGAPORE — State aircraft from other countries, including military aircraft, are not required to file flight plans with Singapore’s Air Traffic Service before flying through its Flight Information Region (FIR), and vice versa.

A country's FIR refers to civil aviation demarcations managed by its ATS, and may or may not overlap with sovereign airspace.

Defence Minister Ng Eng Hen made this clarification on Tuesday (July 6) in response to parliamentary questions by two Workers’ Party Members of Parliament (MPs) over an incident on May 31, when 16 People’s Liberation Army Air Force (PLAAF) aircraft flew through Singapore’s FIR.

Dr Ng added that state aircraft are also not obliged to contact the Air Traffic Service of another country, so long as they fly with due regard to the safety of other aircraft.

Mr Gerald Giam, MP for Aljunied Group Representation Constituency, had asked if the Republic of Singapore Air Force (RSAF) had tracked these flights and established communications with them when they flew through Singapore’s FIR.

Mr Giam also wanted to know how many unannounced entries PLAAF aircraft had made in Singapore’s FIR in the past year.

Mr Dennis Tan, MP for Hougang Single Member Constituency, had asked for the Ministry of Defence’s situational assessment of the incident.

Both MPs also asked about plans to ensure the safety of flights to and from Singapore if tensions rise among claimant states in the South China Sea.

The Chinese planes that had flown through Singapore’s FIR on May 31 had also flown through Malaysian airspace, prompting Malaysia’s air force to scramble its jets. 

The Malaysian Foreign Ministry had also summoned China’s envoy to explain “suspicious” activity detected over the South China Sea, to which several states, including Malaysia and China, have rival claims.

NOT OBLIGED TO FILE FLIGHT PLANS WITH CAAS

In response, Dr Ng clarified that Singapore respects the right of military aircraft and ships to conduct training and passage over areas and waters in accordance with international law, including the United Nations Convention on the Law of the Sea.

Countries conducting military activities in the South China Sea must act in accordance with the Association of Southeast Asian Nations instruments that they have signed, such as the Treaty of Amity and Cooperation, which requires signatories not to take part in activities that threaten each other.

Apart from military activity, the International Civil Aviation Organisation has also designated the Civil Aviation Authority of Singapore (CAAS), a civilian authority, as the Air Traffic Service to ensure the safe and efficient flow of traffic within Singapore’s FIR.

“In this role, (the authority) does not act as watchdog over disputed areas, nor should that authority adopt a partisan role on behalf of any party or for itself,” Dr Ng said.

While civilian aircraft must file flight plans when going through the FIR of an Air Traffic Service authority, military aircraft are not required to do so under international law, Dr Ng added.

“Nevertheless, some militaries, including RSAF, do file flight plans and contact Air Traffic Service authority of that FIR even when they are not legally required to do so. The RSAF routinely adopts this practice primarily to assist the Air Traffic Service authority in coordinating and de-conflicting RSAF flights from civilian aircraft as part of their responsibility for operating with due care.” 

Dr Ng said that with regard to the incident involving PLAAF flights, CAAS did not receive flight plans from the Chinese and it did not communicate with PLAAF or any of its aircraft.

He also stressed that the RSAF has no mandate or any role in managing Singapore’s FIR, which is carried out by CAAS.

DID NOT POSE THREAT

Dr Ng added that the RSAF conducts round-the-clock surveillance of Singapore’s skies to detect potential threats.

On average, the RSAF responds to more than 350 such incidents.

“The specific incident referred to by two members in their questions was not deemed to be such a threat,” Dr Ng said.

In a supplementary question, Mr Giam asked if other countries typically file the flight plans of state aircraft.

Dr Ng replied that many military aircraft from many countries do not file their flight plans or contact the Air Traffic Service authority.