On October 25 Lockheed Martin announced that Belgium had selected the F-35A Lightning II to meet its Air Combat Capability Programme (ACCaP) requirement. Thirty-four F-35As will replace Belgium's fleet of 58 F-16A/B MLU fighters by 2023.

An announcement had originally been expected at the NATO summit in Brussels in June and the initial bids expired on October 14, but the deadline was extended to October 29 at Belgium’s request, to avoid a conflict with municipal elections. Lockheed Martin said that it was honored by the Belgian government’s selection and that it looked forward to supporting the U.S. government in delivering the F-35 to meet the requirements of the Belgian government.

Selection of the F-35 would bring a transformational capability for the Belgian Air Component, the manufacturer averred and would align it with a global coalition operating what it claims is the world’s most advanced aircraft. Lockheed Martin also promised significant industrial participation opportunities for Belgian companies to contribute to the global F-35 enterprise.

Belgium’s foreign minister, Didier Reynders, said that the U.S. bid had been the “best from the price and operational standpoint," though the U.S. Defense Security Cooperation Agency approval of the sale in January was estimated at $6.53 billion for 34 F-35As, 38 Pratt & Whitney F-135 engines, and other equipment, training, logistics, and support.

Factors influencing the decision are understood to have included a desire for commonality and interoperability with the Netherlands, although some believed that selection of the rival Eurofighter Typhoon would have provided Belgium with a complementary and synergistic asset that could operate alongside the Netherlands F-35 Joint Strike Fighters to the benefit of both Benelux air forces. Teaming fourth- and fifth-generation fighters is increasingly being seen as more effective than operating stealthy aircraft alone, with fifth-generation aircraft providing situational awareness and an ability to operate in the most contested airspace, while current-generation fighters can provide greater firepower, persistence, and agility.

It has also been reported that the F-35A’s ability to carry the U.S.-owned B61 nuclear bombs stored at Kleine Brogel was a critical factor, although Eurofighter claimed that feasibility work on the integration of the U.S. B61 nuclear bomb on the Typhoon and that integrating the weapon and developing a secure nuclear weapons-capable stores pylon would have been straightforward. The Typhoon’s nuclear capability was reportedly demonstrated to Belgian air force chief General Vansina in the simulator.

Some Belgian media reports suggested that the Belgian Air Force had manipulated the fighter competition so that only the F-35 could win, but such allegations have been vigorously denied, and the truth is that the F-35A’s formidable operational capabilities swung the decision. Maintaining Belgium’s defense relationship with the U.S. was of secondary importance, while interoperability with other F-35A operators, including the U.S., UK, Denmark, Norway, Italy, and the Netherlands was also a key factor.

Selection of the F-35A was greeted with dismay in France, where the French business journal La Tribune spoke of “betrayal,” while Airbus expressed sincere regret, noting that it remained firmly convinced that the Eurofighter would have represented a superior choice for the country both in terms of operational capability and industrial opportunities and would have provided more than €19 billion in direct contributions to the Belgian economy.