The U.S. Air Force and the U.S. Navy have been quietly working together to develop a new air-to-air missile called the AIM-260 that will replace the venerable AIM-120 Advanced Medium Range Air-to-Air Missile, or AMRAAM. The two services are worried that the Chinese, in particular, have begun to outrange American fighter jets with their own advanced air-to-air missiles. U.S. Air Force Brigadier General Anthony Genatempo, the service’s Program Executive Officer for Weapons, provided details about the new missile in interviews with Aerospace Daily and Air Force Magazine during the Life Cycle Industry Days at Wright-Patterson Air Force Base in Ohio. This event is primarily meant to help Air Force Materiel Command share updates and potential new opportunities with defense contractors, but is also open to the press.

The AIM-260 program, also known as the Joint Air Tactical Missile (JATM), has actually been going on for more than two years already, but this is the first time the Air Force or the Navy has publicly discussed it. At present, the only official mention of the project that is publicly available online appears to be a notice about the assistant program manager, an employee of Naval Air Systems Command, winning an award for outstanding logisticians in 2017. "It is meant to be the next air-to-air air dominance weapon for our air-to-air fighters," Brigadier General Anthony Genatempo told Air Force Magazine. "It has a range greater than AMRAAM, different capabilities onboard to go after that specific threat set, but certainly longer legs."

USAF Airmen move an inert training version of the AIM-120 AMRAAM during an exercise. The JATM is set to eventually replace the AIM-120s as the standard long-range air-to-air missile across the US military.

The threat set Genatempo was talking about is future aerial opponents riding in advanced fighter jets, such as those that Russia and China are developing and are beginning to field, such as the Su-57 and the J-20, respectively. Those two countries have also been developing new, longer-range air-to-air missiles to go with those aircraft. The Air Force officer said that the appearance of the Chinese PL-15, which uses a dual pulse rocket motor, in 2016 was the key factor that drove the Air Force and the Navy to begin the JATM program. Last year, a pair of J-20s flew a particularly notable flight routine at the biennial Zuhai air show with their ventral weapons bays open, showing a full load of four of these missiles.

Rabbit/Chinese Internet A J-20 with four PL-15 missiles in its main ventral weapons bay, as well as a pair of PL-10s on mounts that pop out from its cheek bays, at the 2018 Zuhai Air Show.

There has been much speculation and confusion about what missile this nomenclature refers to over the years and its exact capabilities, but this would seem to suggest that the U.S. military is concerned that it may be close to matching, or even exceeding, the range of the latest AIM-120D variant. Raw range, of course, isn't the only factor in air-to-air combat and the AIM-120D has a host of other advanced features, which The War Zone has previously examined in depth. There is also a possibility that there remains confusion within the U.S. military about the exact nomenclature of Chinese air-to-air missiles. In late 2016, images also emerged of an even longer-range Chinese missile, which has been referred to as both the PL-15 and as the PL-21.

Chinese internet A Chinese J-16 fighter jet carrying a pair of long-range missiles that have been referred to as both the PL-15 and the PL-21.

Whatever the case, in 2017, the JATM program office hired Lockheed Martin to develop the new air-to-air missile. Otherwise, there are still few details about the design. Genatempo did say that the AIM-260 will not use a ramjet, the European Meteor air-to-air missile does, and will have a similar form factor to the existing AIM-120, but did not explain how it would then be possible then to achieve a significant increase in range, according to Aerospace Daily. It is possible that advances in rocket motor and warhead technology may be enough to provide a considerable boost in range when combined with a new, streamlined body. For example, Northrop Grumman's AGM-88G Advanced Anti-Radiation Guided Missile-Extended Range (AARGM-ER) leverages similar developments, including a warhead that offers improved lethality in a smaller package, to create space for additional rocket fuel.

USN A briefing slide showing the internal configuration of the AGM-88G AARGM-ER and the considerable space inside devoted to its solid rocket motor.