The US Air Force is pressing ahead with its programme to certify the modernized thermonuclear free-fall nuclear bomb B61 Mod.12 (B61-12) for use by the F-35A JSF Lightning-II. The implementation of the upcoming software performance block 4 should be the latest.
“This will give commanders – should the President or Vice President give the order – a much wider range of applications in the precise use of the nuclear deterrent option, if this can be done not only from large bombers such as B-5s2 or B-2s, but also from tactical platforms. After the F-15E and F-16C/D, this is the first time that the 5th generation stealth component has been used from its internal weapons bays. It gets closer to potential targets and can penetrate deeper into operational areas than would be possible with non-stealth means,” says USAF spokeswoman Major Emily Grabowski. 
Four variants united
Development of the new B-61 version began back in 2011, and the new weapon is technically a revision or unification of four previously existing variants, B61-3, -4, -7 and -10. Number 12 is characterized by a new tail set, in which an internal navigation system is located for significantly increased precision. https://www.youtube.com/watch?v=acJEyzBKIOE Its nuclear certification on the F-35 is divided into two phases: Nuclear Design Certification and Nuclear Operational Certification. Often (too) simply translated as “wiring”, the “nuclear wiring” process involves more than 50 technical adjustments and modifications to the aircraft systems, both in software and hardware. According to the USAF, these have been taking place in 6-month steps since April 2019 and will continue until October 2024. AMAC (see graphic below) involves the integration of the input station for the nuclear codes, the selection of operating and detonation variants and the magnitude strength of the detonation in 0.3 kilotons, 1.5, 10 and 50 kilotons. 
Insert for Germany
The (simplified) effort described above may also shed light on the discussions surrounding the upcoming type decision for the German Tornado successor. A successor must undergo this adaptation for the so-called “nuclear sharing” – as long as the German Bundestag maintains it – or already have it. It is foreseeable that only US models will be considered for this, although Ursula von der Leyen categorically ruled out the F-35 because of the FCAS cooperation with France – including the replacement of Air Force Chief Müllner. He had – probably rightly – pointed out semi-publicly (Defense-IQ Fighter-Conference) that there would probably be no other models suitable for this role in 2030. He once said to the author in Neuburg: “The 6th generation won’t help me at all when it comes to replacing the Tornado in the near future.” 
Completion of flight tests
On September 21, the live flight tests and risk mitigation measures were completed with the launch of blind practice versions of the B61-12 (known as Joint Test Assemblies). Two production F-35As from the 422nd and 59th Test and Evaluation Squadrons from Nellis AFB dropped those JTAs of the B61-12 nuclear bomb at the Tonopah Test Site in a mission-typical manner, completing their technical certification process for the tactical nuclear bomb. The release took place at an altitude of 3,500 meters and the drop lasted 42 seconds.
According to the USAF, this was the first drop of the most representative (newest) B61-12, which is also a so-called “bunker buster”. The data obtained in a total of ten test launches is currently being analyzed and reviewed by the US Department of Defense and Energy (which is responsible for nuclear bombs) to ensure that the F-35A and B61-12 JTAs function correctly in all phases of deployment. And unlike the F-15E and F-16C/D, this also involves missions from the weapons bay and at supersonic speeds.
In the information released by Sandia National Laboratories, no end date for full nuclear certification of the F-35A has been announced. Also, by no means will all F-35s be nuclear capable after full certification for real-world use. Only those squadrons/squadrons with a nuclear mission will receive the hardware and personnel required to configure and maintain the nuclear-capable F-35. These are expected to be the “Dual Capable Aircraft” (DCA) F-16C/D units first, which will be converted to the F-35 or newly deployed. For example, the 495th Fighter Squadron “Valkyries” in Lakenheath, England, which was newly equipped with 27 F-35As on October 1. Later, with a second squadron, the number is to rise to 48 aircraft. In June, NATO Supreme Allied Commander USAF General Tod D. Wolters said in a speech that there will be around 450 F-35s operated by the USA and its allies in Europe in 2030.
What is Sandia?
Previously, in partnership with the National Nuclear Security Administration (NNSA), Los Alamos National Laboratory and the USAF, Sandia conducted a B61-12 full weapon system demonstration with the Boeing F-15E Strike Eagle fighter jet in March and another with the B-2 Spirit bomber in July. Sandia is the design and development laboratory for non-nuclear components of the nation’s nuclear stockpile, including the B61-12. In addition to developing non-nuclear components, Sandia serves as the technical integrator for the entire weapon. “We are demonstrating the greater compatibility and higher versatility of the B61-12 for the nation’s nuclear deterrent, and we are doing so in a more disruptive world and one with Covid-19,” said Steven Samuels, a manager of Sandia’s B61-12 Systems teams.
