Denmark purchases 340 AIM-9X Block II Sidewinder air-to-air missiles following U.S. approval
{loadposition bannertop}
{loadposition sidebarpub}
Denmark received U.S. approval for a potential $318.4 million acquisition of AIM-9X Block II Sidewinder missiles, including 340 missiles and 34 tactical guidance units, through a new Foreign Military Sale (FMS).
On November 12, 2025, Denmark received the approval of the United States for a possible acquisition of AIM-9X Block II Sidewinder air-to-air missiles valued at an estimated $318.4 million, establishing a significant modernization step for the Royal Danish Air Force’s short-range air-to-air capabilities. This Foreign Military Sale (FMS) includes up to 340 AIM-9X Block II missiles and 34 AIM-9X Block II tactical guidance units supported by a broad package of training, logistics, and technical assistance. This proposed sale places Denmark among the European air forces opting for the Block II variant as new F-16 and F-35 fleets transition to more modern infrared-guided missile families.Follow Army Recognition on Google News at this link
The AIM-9X Block II upgrade integrates a datalink enabling lock-on-after-launch (LOAL) capability for engagements beyond visual range or in rear hemisphere positions relative to the launch aircraft. (Picture source: US Air Force)
The Danish request covers a complete procurement framework that includes the missiles, guidance units, training aids, weapon software, operational and technical training, support equipment, spare and repair parts, transportation, and the provision of publications and technical documentation. It also incorporates engineering, technical, and logistics support from U.S. government personnel and contractors, creating a comprehensive introduction-to-service structure rather than a limited missile transfer. The total estimated cost of $318.4 million covers hardware and all associated support elements that ensure Denmark can sustain the AIM-9X Block II across its operational lifespan. This acquisition approach aligns with broader patterns seen in other European F-35 operators that pair fighter procurement with full missile training pipelines. Belgium, Norway, and Romania have taken similar steps, albeit in separate arrangements, illustrating growing NATO standardization.
The AIM-9X Sidewinder is a short-range air-to-air missile produced in the United States for detection, acquisition, interception, and destruction of airborne threats in day and night conditions, forming part of the long-running AIM-9 family first developed in the early 1950s. It incorporates a 128×128 focal plane array imaging infrared seeker, offers high off-boresight engagement capability, sometimes described as up to about 90 degrees, and integrates with helmet-mounted cueing systems used by modern fighter aircraft. The missile employs a thrust vectoring control system and aerodynamic control surfaces to provide high maneuverability in close-range situations. It retains the warhead and motor lineage of the AIM-9M while introducing improvements in guidance electronics, drag reduction, and handling performance. Denmark’s adoption of this configuration follows similar integrations made by U.S. and several NATO Air Forces on F/A-18, F-15, F-16, and F-35 fighters.
The AIM-9X Block II variant extends the baseline missile’s capabilities with hardware and software upgrades that include a redesigned fuze, a digital ignition safety device intended to improve safety during handling and flight, and updated processors that allow enhanced counter-countermeasure performance. The Block II version also introduces a datalink providing lock-on-after-launch capability, enabling the missile to receive target updates after leaving the aircraft and allowing engagements beyond visual range in certain tactical contexts. This datalink also supports rear hemisphere engagement when aircraft sensors or allied platforms maintain tracking data. Tests that began in 2008 confirmed the Block II’s ability to meet or exceed performance thresholds for these advanced launch profiles, although software improvements continued through subsequent years. Program evolution remains active, with updates addressing obsolescence, seeker element refinements, and sensor integration.
The AIM-9X has a length of approximately 3.02 meters, a body diameter of 12.7 centimeters, a launch mass between 84 and 86 kilograms, and a fin span of about 44.4 centimeters. The warhead is the WDU-17/B annular blast fragmentation type, weighing roughly 9.4 kilograms. The missile uses a solid propellant rocket motor, an imaging infrared homing seeker, and guidance algorithms based on proportional navigation. Its engagement ranges remain classified, although missiles in this category typically operate across distances measured in tens of kilometres, depending on launch geometry and target behavior. Cost figures from 2019 indicate that AIM-9X Block II tactical rounds had approximate unit prices of $381,070, Block II Plus versions around $399,500, and training missiles approximately $209,493. Denmark’s procurement falls within the family of systems supported by captive-carry training missiles, special training missiles, and guidance units developed for evaluation. These elements facilitate force conversion programs, similar to those implemented in Belgium and Norway as they transitioned to newer F-35s.
The missile is already fielded across several U.S. fighter jets, including the F/A-18C/D, F/A-18E/F, F-15C/D, F-15E/EX, and F-16C/D, and is also incorporated into the F-35 that is progressively becoming a common fighter across Europe. Denmark’s acquisition, therefore, enables immediate compatibility with aircraft and weapons already used by Belgium, Italy, Romania, Norway, and other partners that have adopted AIM-9X for F-16 or F-35 fleets. While several of these countries have larger missile allocations, each procurement reflects similar operational requirements for infrared guidance resilience and high off-boresight engagements. Denmark’s transition to this configuration ensures interoperability and reduces the need to maintain older Sidewinder models, which previously formed the baseline armament for many NATO air forces.
Written by Jérôme Brahy
Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.
{loadposition bannertop}
{loadposition sidebarpub}
Denmark received U.S. approval for a potential $318.4 million acquisition of AIM-9X Block II Sidewinder missiles, including 340 missiles and 34 tactical guidance units, through a new Foreign Military Sale (FMS).
On November 12, 2025, Denmark received the approval of the United States for a possible acquisition of AIM-9X Block II Sidewinder air-to-air missiles valued at an estimated $318.4 million, establishing a significant modernization step for the Royal Danish Air Force’s short-range air-to-air capabilities. This Foreign Military Sale (FMS) includes up to 340 AIM-9X Block II missiles and 34 AIM-9X Block II tactical guidance units supported by a broad package of training, logistics, and technical assistance. This proposed sale places Denmark among the European air forces opting for the Block II variant as new F-16 and F-35 fleets transition to more modern infrared-guided missile families.
Follow Army Recognition on Google News at this link
The AIM-9X Block II upgrade integrates a datalink enabling lock-on-after-launch (LOAL) capability for engagements beyond visual range or in rear hemisphere positions relative to the launch aircraft. (Picture source: US Air Force)
The Danish request covers a complete procurement framework that includes the missiles, guidance units, training aids, weapon software, operational and technical training, support equipment, spare and repair parts, transportation, and the provision of publications and technical documentation. It also incorporates engineering, technical, and logistics support from U.S. government personnel and contractors, creating a comprehensive introduction-to-service structure rather than a limited missile transfer. The total estimated cost of $318.4 million covers hardware and all associated support elements that ensure Denmark can sustain the AIM-9X Block II across its operational lifespan. This acquisition approach aligns with broader patterns seen in other European F-35 operators that pair fighter procurement with full missile training pipelines. Belgium, Norway, and Romania have taken similar steps, albeit in separate arrangements, illustrating growing NATO standardization.
The AIM-9X Sidewinder is a short-range air-to-air missile produced in the United States for detection, acquisition, interception, and destruction of airborne threats in day and night conditions, forming part of the long-running AIM-9 family first developed in the early 1950s. It incorporates a 128×128 focal plane array imaging infrared seeker, offers high off-boresight engagement capability, sometimes described as up to about 90 degrees, and integrates with helmet-mounted cueing systems used by modern fighter aircraft. The missile employs a thrust vectoring control system and aerodynamic control surfaces to provide high maneuverability in close-range situations. It retains the warhead and motor lineage of the AIM-9M while introducing improvements in guidance electronics, drag reduction, and handling performance. Denmark’s adoption of this configuration follows similar integrations made by U.S. and several NATO Air Forces on F/A-18, F-15, F-16, and F-35 fighters.
The AIM-9X Block II variant extends the baseline missile’s capabilities with hardware and software upgrades that include a redesigned fuze, a digital ignition safety device intended to improve safety during handling and flight, and updated processors that allow enhanced counter-countermeasure performance. The Block II version also introduces a datalink providing lock-on-after-launch capability, enabling the missile to receive target updates after leaving the aircraft and allowing engagements beyond visual range in certain tactical contexts. This datalink also supports rear hemisphere engagement when aircraft sensors or allied platforms maintain tracking data. Tests that began in 2008 confirmed the Block II’s ability to meet or exceed performance thresholds for these advanced launch profiles, although software improvements continued through subsequent years. Program evolution remains active, with updates addressing obsolescence, seeker element refinements, and sensor integration.
The AIM-9X has a length of approximately 3.02 meters, a body diameter of 12.7 centimeters, a launch mass between 84 and 86 kilograms, and a fin span of about 44.4 centimeters. The warhead is the WDU-17/B annular blast fragmentation type, weighing roughly 9.4 kilograms. The missile uses a solid propellant rocket motor, an imaging infrared homing seeker, and guidance algorithms based on proportional navigation. Its engagement ranges remain classified, although missiles in this category typically operate across distances measured in tens of kilometres, depending on launch geometry and target behavior. Cost figures from 2019 indicate that AIM-9X Block II tactical rounds had approximate unit prices of $381,070, Block II Plus versions around $399,500, and training missiles approximately $209,493. Denmark’s procurement falls within the family of systems supported by captive-carry training missiles, special training missiles, and guidance units developed for evaluation. These elements facilitate force conversion programs, similar to those implemented in Belgium and Norway as they transitioned to newer F-35s.
The missile is already fielded across several U.S. fighter jets, including the F/A-18C/D, F/A-18E/F, F-15C/D, F-15E/EX, and F-16C/D, and is also incorporated into the F-35 that is progressively becoming a common fighter across Europe. Denmark’s acquisition, therefore, enables immediate compatibility with aircraft and weapons already used by Belgium, Italy, Romania, Norway, and other partners that have adopted AIM-9X for F-16 or F-35 fleets. While several of these countries have larger missile allocations, each procurement reflects similar operational requirements for infrared guidance resilience and high off-boresight engagements. Denmark’s transition to this configuration ensures interoperability and reduces the need to maintain older Sidewinder models, which previously formed the baseline armament for many NATO air forces.
Written by Jérôme Brahy
Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.
