A US refueling transport plane that took off from Bucharest is returning due to a possible emergency situation on board, an air traffic control source told TASS.
“A Boeing KC-135R Stratotanker belonging to the US Air Force took off from Bucharest airport about an hour ago. While in Greek airspace, it made a sharp turn and returned, transmitting a possible distress signal“, the source told the agency. He did not specify the exact cause of the possible emergency situation on board, nor where the plane was headed, but noted that it is now near Bucharest.
According to the source, the plane made its first flight approximately 65 years ago.
The information that the American Boeing KC-135R Stratotanker sent a distress signal is also confirmed by online global air traffic monitoring systems. They recorded the crew broadcasting the code “7700“, indicating an emergency situation on board.
On the evening of March 27, a US Air Force transport plane made an emergency landing in Turkey after taking off from an airport on the Greek island of Kos. An air traffic control source said the plane was approximately 20 years old.
The Boeing KC-135R Stratotanker is the US Air Force's primary aerial refueling tanker, designed to refuel other aircraft in the air.
The KC-135R variant is the most modern version of the platform, the result of a major upgrade program.
It is equipped with four CFM56 (F108) engines, which are more powerful, economical and quieter than the original turbojet engines.
The upgrade allows it to carry up to 50% more fuel and reduces fuel consumption by about 25% compared to older models.
It mainly uses a rigid connection (boom), but can also be equipped with flexible systems for refueling allied aircraft.
The aircraft The KC-135R is actively involved in large-scale operations in the Middle East. On February 28, 2026, more than 30 KC-135 and KC-46 tankers were deployed in support of joint US-Israeli strikes.
On March 12, 2026, a KC-135 crashed in western Iraq after a refueling incident, killing all six people on board.
Several aircraft of this type were reportedly damaged in Iranian missile strikes on military bases in the region in March 2026.
Despite their age (some aircraft have been in service since the late 1950s), the KC-135R remains the backbone of American strategic aviation.