The three events involved an Antonov An-26 transport plane on Monday, 18 February, an Ilyushin Il-78 refuelling tanker two days later on the Wednesday, and on Friday, 22 February, a Sukhoi Su-30SM fighter jet.

None of the Russian planes had pre-filed flight plans, it is reported, and their on-board transponders were not functioning, though some of the flights maintained radio communications with Baltic air traffic controllers.

The Kaliningrad region remained under Russian rule after the collapse of the Soviet Union, finding itself cut off from the Russian ''mainland'' as it is separated to the east by the present-day EU nations of Lithuania and Poland (and east of those, Belarus) and to the west by the Baltic sea. As a result, Russian planes flying to and from the heavily-militarised Kaliningrad zone often ''cut the corner'' close to NATO-controlled airspace in the Baltic States and Poland. When this happens, NATO jets stationed at Šiauliai in northern Lithuania and Ämari in northwestern Estonia intercept and escort the Russian planes.

The Sukhoi Su-30 is a multi-role fighter jet which has been in service with the Voyenno-Vozdushnye Sily Rossii, the Russian airforce, for over 20 years. The Antonov An-26 twin turboprop is a much older plane; production of the transport craft had ceased before the Soviet Union collapsed. The Ilyushin Il-78 is a four-engined aerial refuelling tanker place which came into service in the mid-1980s and was based on the earlier Il-76 strategic airlifter, designed by the Ilyushin Design Bureau, producer of the World War Two-era Il-2 ground attack aircraft, the single most-produced military aircraft design of all time.