Bulgaria’s First F-16 Block 70 Fighter Grounded after System Issue Detected

Bulgaria’s first F-16 Block 70 fighter jet has been grounded after a system deviation was detected during its acceptance process, according to Air Force Commander Major General Nikolay Rusev.

The problem was identified after the aircraft landed in Bulgaria on April 2, though it remains unclear whether the issue arose during the flight or post-landing. “The detection of a system deviation does not mean that the aircraft is faulty,” Rusev clarified.

The two-seat F-16, delivered by Lockheed Martin, is Bulgaria’s first under its current modernization effort. Official induction into service has been postponed until the completion of technical and flight tests, which include at least two test flights with a Bulgarian pilot. “The aircraft will be included in the Bulgarian Air Force inventory only after the pilot confirms that it is airworthy,” Rusev said.

Bulgarian Defense Minister Atanas Zapryanov confirmed that all funding for the aircraft acquisition, along with necessary infrastructure at the Third Air Base, has been secured. Zapryanov noted that discussions are ongoing with the U.S. government for long-term logistics and spare parts supply.

Former Defense Minister Dimitar Stoyanov said the aircraft is currently unable to fly due to a faulty unit and explained that the required spare part was not included in the original package. “Such malfunctions are common during early use of new aircraft and must be addressed before further flights,” he stated.

Stoyanov criticized the absence of spare parts, attributing the issue to cost-saving decisions by a previous government. He said the problem could have been avoided if Bulgaria had accepted an offer that included guaranteed round-the-clock delivery of spares.

The F-16 was welcomed at a ceremony on March 13 and was expected to start operational duty after evaluations. Seven more aircraft under the initial contract are set to arrive by the end of 2025, with eight more due by 2027, completing Bulgaria’s F-16 Block 70 fleet.

A political dispute has emerged over the issue, with former Prime Minister Boyko Borissov accusing the government of mishandling the procurement. President Rumen Radev pointed to broader problems in defense planning but did not confirm specific operational details.

Meanwhile, Slovakia, which received its own F-16 Block 70s from the same production line, has reported no such issues with its aircraft.