India has announced the closure of airspace over an area around the Andaman and Nicobar Islands in the Bay of Bengal and the Andaman Sea for three hours each on May 23-24 for a planned air activity, and no civilian aircraft will be allowed to use the specified airspace at any altitude, according to a recent Notice to Airmen (NOTAM) issued by the Indian authorities.
The NOTAM was issued on Friday (May 16) evening. It is not mandatory for the exact nature of the air activity to be mentioned in the NOTAM.
A review of past NOTAMs issued for military exercises and weapons tests shows that the specific nature of the activity was mentioned in a number of notices, while a few were non-specific. But the location and certain particulars of this NOTAM may be interpreted as indicative of a missile or weapons system test.
The Andaman and Nicobar Islands region has been used time and again by India for missile tests, with the test firing of the BrahMos supersonic missile in salvo mode in January 2025 being a recent example. In April last year, India successfully tested an air-launched ballistic missile in the Adamans, and in March 2022, a successful test firing of the extended range BrahMos missile was done from a launch pad in the island group.
According to the NOTAM, the specified airspace—over a polygonal area around the Andaman and Nicobar Islands with maximum corridor length of around 500 km—will be restricted between 01:30 and 04:30 UTC (7 am and 10 am IST) on May 23 and 24, and consequently nine international flight routes will be closed for these periods without any alternative routes being made available. The affected altitudes are listed as ground to unlimited, which means that civilian aircraft are not allowed to operate even at very high altitudes over the specified area during the restriction windows.
As the NOTAM is for a specified three-hour window on both days, covers a large area, is applicable for all altitude levels from the ground up, and does not make available any alternative routes for civilian aircraft, it could be indicative of a missile test or a high-altitude weapons test. Such broad closures without alternative routes usually signal sensitive or hazardous operations that require civilian aircraft to be kept completely out of range. For activities like aerial surveys, usually lower altitudes are used, which do not interfere with high-altitude flight paths.
Emails to the Airports Authority of India, Ministry of Defence, Defence Research and Development Organisation (DRDO), and the Indian Space Research Organisation () have not elicited any response so far.
