 NATO increases aircraft readiness after Russian Su-35 incident in the Black Sea. The North Atlantic Alliance has put its air policing units on high alert following an incident between a Russian Su-35 fighter jet and a Polish aircraft of the European Union's Frontex border mission in the Black Sea. Reuters reported NATO air policing detachments were put on higher readiness in response to the dangerous behavior of a Russian military plane in the vicinity of a Polish Frontex aircraft over the Black Sea near Romania. The report cited a NATO official who spoke on condition of anonymity. The NATO official added that the alliance remains vigilant and referred all further questions about the incident to the Polish authorities. On the 5th of May, a Russian Su-35 fighter jet reportedly performed a dangerous interception of an L-410 Turbolet aircraft belonging to the Polish Border Guard service, which was on a scheduled patrol mission under the auspices of Frontex over the Black Sea in international airspace in cooperation with Romanian services. The incident led to severe turbulence for the Polish Border Guard aircraft. During the incident, the five-person Polish Border Guard crew temporarily lost control of the aircraft and began to lose altitude.