Boeing LRAAM: air-to-air missile concept to replace AMRAAM
LRAAM rocket model
Boeing has joined the development of a promising air-to-air missile and is ready to show its development. The other day she showed a model of the LRAAM product, showing the main provisions and solutions of the project. Perhaps in the future this concept will receive support from the Air Force and will be brought to service.
Next generation
Work on promising long-range air-to-air missiles in May last year was launched by the US Air Force Research Laboratory (AFRL). She issued a request for information, the purpose of which is to find technologies and solutions for the subsequent design of real missiles. Applications from potential contractors were accepted until mid-June. As is now clear, Boeing responded almost immediately to AFRL's request.
AFRL believes that in the long term, the existing AIM-120 AMRAAM and AIM-9X Sidewinder missiles will no longer meet current requirements. Accordingly, it is necessary to work out the issues of their modernization or replacement with completely new air-to-air missiles. Such weapon in the future, it can supplement the already developed product AIM-260 JATM and provide high combat effectiveness of fighters.
The request lists "soft" requirements for future projects, and also provides for the choice of optimal solutions. Severe restrictions apply only to the dimensions of the rocket. It will be used by modern fighters, and therefore its length must correspond to the dimensions of their internal cargo compartments. Product is limited to 156 inches (approx. 4 m) in length.
There were no specific propulsion requirements and AFRL is ready to consider any systems. At the same time, technologies for creating throttled impulse solid fuel engines, as well as improved fuel compositions, are of particular interest to the Laboratory. The type of homing can be any, but preference will be given to a system that combines high performance, a modern component base and a reasonable cost.
According to flight data, a hypothetical rocket should at least not be inferior to existing models. It is also necessary to improve the combat characteristics - to create an improved compact warhead and ensure that the target is hit by one missile.
First layout
On September 20, the Air, Space, and Cyber Conference of the Air Force Association opened in the United States. This event is traditionally a platform for the demonstration of various developments in the field of combat aviation... Boeing became one of the exhibitors.
Boeing's booth is showcasing a mock up of the Long-Range Air-to-Air Missile (LRAAM) rocket, a concept developed in response to last year's AFRL request. Some technical and other information is also provided. At the same time, the project is in its earliest stages, and some of its aspects have not yet been worked out. In particular, the developers cannot reveal even the most basic characteristics.
The model demonstrates a two-stage air-to-air missile, the dimensions of which fit into the customer's limitations. The steps have a similar appearance and are maximally unified in design and units. Both stages have a cylindrical hull with a low aspect ratio X-shaped wing and tail rudders. Some of these planes are installed on longitudinal fenders. The combat stage has an elongated warhead with a radio-transparent fairing. The head part of the second stage is shorter and is made in the form of a cone for connection with the combat one.
Such a stage design in the future should simplify production and reduce the cost of serial missiles. In this case, the steps are developed from scratch and without borrowing parts from other projects.
The LRAAM project provides for the use of a solid propellant propulsion system in both stages. After dropping from the carrier, the first stage should accelerate the rocket to cruising speed and ensure flight to the target. After running out of fuel, the empty hull is dropped, and the combat stage begins an independent flight - first with the engine, and then due to the accumulated energy.
F-22A fighter cargo bay. Gray product on the right - AIM-120 serial missile
The design of the fairing indicates the use of a radar seeker, but no precise information has been given. The method of hitting the target also remains unknown. The combat stage can carry a traditional high-explosive fragmentation warhead, but it will reduce the available volumes for the engine. It is also possible to abandon warheads, and a highly effective seeker will provide a direct hit on the target.
Future technologies
While the LRAAM project is in its earliest stages, however, now we are talking about the selection of key solutions and technologies that in the future will determine the final appearance, characteristics and capabilities of the rocket. And already now it is possible to consider the proposed ideas, as well as determine their potential.
Of greatest interest in the LRAAM concept is the two-stage scheme, which is not typical for air-to-air missiles. With its help, the active phase of the flight is divided into two parts. The first is completed by dropping the spent stage, which optimizes weight and energy characteristics, and therefore improves flight performance and maneuverability.
All this makes it possible to increase the firing range in comparison with current missiles, while maintaining acceptable dimensions. Based on this, it can be assumed that the final version of LRAAM will show a range no less than that of the latest AIM-120 AMRAAM modifications, i.e. more than 150-170 km.
The presented layout makes rather high demands on all major systems, incl. to the seeker and warhead. First of all, layout difficulties are likely. The combat stage has limited volumes, in which all units must be placed without loss in their characteristics. Perhaps the control systems are planned to be installed in the elongated head of the stage. The warhead may simply be absent, which will give additional volumes for solid fuel and improve the flight range.
AMRAAM missile transportation
The missile needs a highly efficient active radar seeker. She will have to detect and lock targets in a wide range of ranges. At the same time, it is necessary to ensure the ability to detect inconspicuous aircraft and resistance to modern electronic warfare systems.
In the long term, the combat stage can become an independent weapon. Due to the lack of initial acceleration, the firing range will be significantly reduced, but all other advantages and features of the "long" missile will be retained.
With uncertain prospects
The presented concept of the LRAAM rocket offers the use of the most interesting solutions, incl. fundamentally new, and therefore should be of interest to both the AFRL and the Air Force as a whole. However, the timing of the start and implementation of design work, as well as the entry into the testing stage, are still in question. Moreover, there are no obvious reasons for optimistic assessments either.
Apparently, the Boeing company began working on the LRAAM concept no later than the summer of 2020. More than a year has passed since then, and during this time it was only possible to determine the most general features of the future rocket and prepare its layout. This can be explained by the fact that AFRL does not speed up work and does not urgently require the submission of a combat-ready model, and Boeing is in no hurry. However, there is another explanation associated with the complexity of the tasks and the inability to solve them in a short time.
Obviously, the development of the concept will continue, and in the medium term it may lead to the emergence of a full-fledged project. By that time, the Air Force Laboratory will have to move from considering proposals to a full-fledged competition, according to the results of which future rearmament will be carried out. Most likely, Boeing will take part in a full-fledged missile development program. Which companies will compete is unknown.
Thus, the situation in the field of promising air-to-air missiles for the US Air Force is beginning to gradually clear up, but there is still great uncertainty in it. The future customer in the person of the Air Force Research Laboratory is looking for the necessary technologies, and one of the leading contractors is already ready to present his ideas, even at the level of a concept project. In the near future, the announcement of new similar developments is expected. The Air Force will compare them and make their decision - and then the real potential of the current LRAAM concept will become clear.
- Ryabov Kirill
- Thedrive.com, US Department of Defense
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