Flight safety officers at Hang Nadim International Airport in Batam, Riau Islands, allege they detected several Singaporean fighter jets flying over the island without permission and feared the development increased the risk of a fatal collision with a commercial flight.
The head of the airport's flight safety division, Indah Irwansyah, said that on Friday an F-16 or F-4 fighter allegedly belonging to the Singaporean military was detected over Batam. It headed from Singapore to airspace over Sekupang district and then moved on to Nipah Island.
'It moved very quickly, so it was difficult to detect as we don't have radar here at Hang Nadim,' Indah said on Saturday.
According to Indah, the aircraft was monitoring Nipah Island, which borders Batam and Singapore.
'Singapore is very interested in Nipah while Indonesia continues to maintain it. The fighter was flying low,' she said.
Indah said the fighter's movements should have been made known by the Singaporean military to the Indonesian Transportation Ministry, so that the latter could inform the local airport, which would in turn inform commercial flights in the area of the fighter's presence.
'We received no information about the fighter. If we did, we would've informed the relevant parties,' she said.
She suggested that Hang Nadim be equipped with a radar so the airport would be able to identify all flights, commercial or otherwise, flying over the border area. She added that if this was the case, flight safety officers would have been able to read the fighter's squawk code, a four digit identification number transmitted by the transponder of the passing aircraft, enabling them to detect the aircraft's type and flight route.
'Normally, military aircraft are reluctant to reveal their squawk codes as they are linked to classified missions,' Indah said.
Visiting Coordinating Political, Legal and Security Affairs Minister Djoko Suyanto said he was not aware of a problem. He said the issue was linked to the technical matter of an aircraft landing or taking off from Singapore and flying over Batam.
'With regard to airspace you must ask the Transportation Ministry, not me,' he said.
The minister was in Batam to inaugurate the Kuda Laut 4803 Ship.
'The patrol ship has an important role to support the task of Bakorkamla [Maritime Security Coordinating Board] in securing Indonesia's maritime area,' he said.
The possibility of Singaporean fighter jets using Indonesian airspace without permission could add to existing tensions between the countries.
The Singapore government recently expressed its anger at Indonesia's decision to name its frigate after Osman Haji Mohamed Ali and Harun Said ' two marines executed for a bombing in the city state's main shopping district that left three people dead in the 1960s.
In response, the Indonesian government defended its decision and said it was in line with its practice of naming vessels after its national heroes.