US Air Force interested in integrated circuit aircraft
Boeing X-48B - an experienced UAV for testing a new scheme
The US Air Force plans to explore the possibility of creating fundamentally new military transport aircraft and air tankers. For a sharp increase in useful volumes and carrying capacity of such equipment, it is proposed to use the so-called. integrated aerodynamic scheme. In the near future, it is planned to conduct the necessary research, and in the future, the launch of a full-fledged project is not ruled out.
Looking for profit
Aviation Week announced the new plans for the US Air Force on July 7. According to him, over the next few days, the Pentagon was going to release the so-called. request for information on a military transport aircraft and/or tanker of an unusual design. In the next few weeks, the Air Force will accept applications for participation in the research program, and then select a contractor.
It is reported that so far it is only about conducting research work. The customer has determined the basic requirements for hypothetical aircraft, and the performers will have to form the optimal appearance of such equipment and scientifically substantiate it. The timing of such studies is not specified, but the contract value reaches $56,9 million.
The wishes of the Air Force for the new project are generally simple. It is necessary to find the optimal variant of the design of an integrated circuit aircraft (Blended Wing Body), showing increased flight and economic performance. It is assumed that the unusual scheme will improve aerodynamics and related characteristics, as well as increase the available volumes to accommodate the payload.
Model HWB aircraft from Lockheed Martin in a wind tunnel
The transporter and tanker on the new platform must surpass the existing equipment of their classes in terms of economy and flight range. It is also expected to obtain a significant reduction in operating costs. So, the Air Force wants a full translation. fleet tankers for new equipment gave annual savings of at least $2 billion.
Whether these requirements can be met is unknown. In the near future, the Pentagon will accept applications and select a contractor who will conduct the necessary studies and form a technical proposal. If the preliminary design meets the requirements of the customer, then a new contract for the full development of new aircraft may appear. However, the success of such research is not guaranteed.
perspective scheme
The integrated aerodynamic scheme was proposed quite a long time ago, but the active development of this idea began only in the nineties of the XX century. with the advent of new methods of research and design. Using these ideas, a lot of different projects were developed, but the vast majority of them did not even reach the construction and testing of experimental equipment.
HWB in flight
From a technical and aerodynamic point of view, an integrated circuit is a cross between a flying wing and a tailless one. The basis of such a glider are swept planes of a large area, like a flying wing. At the same time, a pronounced fuselage is preserved, the surface of which smoothly flows into the bearing planes. It is possible to use various protruding elements: engine nacelles, keel ends, etc. In some projects, the tail unit is also used.
Such an aircraft design is characterized by a certain complexity at the development stage. It is necessary to combine high aerodynamic characteristics and structural strength. At the same time, the presence of a large number of sags and fairings simultaneously complicates and simplifies design tasks.
As in the case of a flying wing, the integrated circuit gives a gain in flight performance and economic performance. An aircraft of this kind has the maximum possible bearing surface and all the accompanying advantages. In this case, there are restrictions on maximum speed, maneuverability, etc.
Cargo placement in the HWB fuselage
Like a flying wing, the integrated circuit is distinguished by the large internal volume of the airframe. So, in a wing of a large area, tanks of increased capacity can be placed. At the same time, the integrated circuit provides for the presence of a pronounced fuselage, which can accommodate a cargo or passenger cabin of sufficient volume.
All the advantages of an integrated circuit can be used to create passenger aircraft, transporters or tankers. Thus, a large wing area will allow the transport aircraft to take on board more cargo, and the tanker will be able to carry and transfer more fuel. With all this, they will be more economical than their counterparts in the normal circuit.
Finished developments
It is curious that the US Air Force is just launching a new research program, and its potential participants already have developments on this topic. So, back in 2016, Lockheed Martin presented the original concept of a refueling aircraft or a “hybrid” transporter (Hybrid Wing Body – HWB).
This project proposed the construction of an integral aircraft with a swept wing and a characteristically shaped fuselage. On the rear fuselage, immediately behind the wing, there are two engine nacelles. A T-tail was also used. Other options for the aerodynamic shape were also considered, incl. with a different plumage design.
By the time of the first announcement, the HWB project had entered the research and testing stage. A scale model of such an aircraft with a wingspan of approx. 3 m and weight approx. 20 kg, equipped with a pair of electric motors. It was tested in a wind tunnel, and the first free flight with radio control was expected in the near future.
A full-size HWB aircraft was to have a 76 m wingspan and a cargo compartment of the appropriate dimensions. According to calculations, its carrying capacity should be at the level of the serial C-5 - about 125 tons. With similar flight characteristics, fuel consumption should be 70% lower than that of the existing C-17.
It is known that the HWB project from Lockheed Martin went through the research stage and provided the collection of the necessary data. It was assumed that in the near future, developments on it will be able to be used to create a real aviation technology. However, this did not happen - due to the lack of interest from potential customers.
Unpredictable future
It can be assumed that Lockheed Martin will be interested in the new Air Force request and take the necessary measures. She can return the HWB project from the archive and re-offer it to a potential customer. In addition, other aircraft manufacturers, including developing similar projects. Which company will offer the best conditions and interest the Air Force is unknown.
Whether the performer will cope with the tasks set is a big question. The formation of the appearance of an aircraft of an unusual scheme as a whole will not be a big problem. The experience of the last decades and a number of well-known projects confirm this. However, the Pentagon imposes special requirements on flight and economic characteristics for a promising transporter and tanker. It cannot be ruled out that such a technical task will turn out to be too complicated, and it will not be possible to achieve all the specified parameters.
However, so far we are talking only about research work, and any result of it will be useful for the Air Force. If the contractor copes with all the tasks and forms the optimal appearance of the aircraft with the necessary characteristics and capabilities, then this can be followed by a full-fledged design. Failure at the R&D stage, in turn, will show weaknesses in the terms of reference and the new concept - and will also help determine where to focus in future work.
Distant perspective
The US Air Force has plans to develop its military transport aviation and tanker fleet for several years to come. It is envisaged to continue the operation of existing machines and gradually replace the oldest ones with new production equipment. At the same time, the list of aircraft for new purchases for the coming years has already been determined.
So far, the Air Force plans to purchase only equipment of already known types, and these are aircraft of a normal aerodynamic design. Technique of a different appearance is not even in the plans. However, now the Pentagon is ready to consider alternative schemes and, if there are advantages, to accept them into operation. Whether the integrated architecture of aircraft will be able to get into the field of air transport will become known in a few years, after the completion of the program starting now.
- Ryabov Kirill
- NASA Lockheed Martin
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