Currently, the US military uses a wide range of different means to supply remote or isolated units. In the near future, the existing systems may receive an addition in the form of promising unmanned gliders developed by Logistic Gliders Inc.
Supply problems
In certain situations, supplying troops by air can be difficult. There may not be an airfield for a transport aircraft in place, and helicopters are vulnerable to enemy air defenses. The same applies to military transport aircraft dropping parachute platforms.
In this regard, the US Marine Corps and DARPA have launched the TACAD (Tactical Air Delivery) research program, which aims to create a new air transport for the delivery of small cargoes with minimal risk.
Taking into account the level of technology development, the customers proposed to develop specialized transport UAVs of a simplified design. Such a product should carry a load of hundreds of kilograms, be launched by dropping from standard ILC aircraft and fly tens of miles through the air. Reuse is optional. The cost of the drone is capped at $ 11,000. Ammunition, provisions, medicines, etc. are considered as potential loads.
One of the participants in the program is the California-based company Logistic Gliders. Back in 2018, she patented the original design of an unmanned airframe, and by now has brought two types of such equipment with different characteristics to the test.
Two gliders
The Logistic Gliders company offers the customer two variants of the UAV under the names LG-1K and LG-2K. The first project was developed with the participation of specialists from the Marine Corps Warfighting Laboratory, the second was created in cooperation with DARPA. At the same time, the same solutions are at the heart of both developments.
Both projects propose the construction of a non-motorized aircraft with a normal aerodynamic design. To reduce the cost of production, most of the parts are made of plywood. For the same purpose, the glider has rough contours. The main part of the fuselage is given under the cargo compartment, and the minimum necessary controls are located in the tail.
The fuselage of the LG-1K and LG-2G gliders is made in the form of a plywood box of specified dimensions. The flat nose cone acts as a shock absorber during landing. In the central part of the fuselage, a straight wing of large aspect ratio, which can be deployed in flight, is mounted. When transported by the carrier, the planes are located along the fuselage, and when dropped, a special mechanism translates them into an operating position. The tapering tail carries a plumage with a stabilizer, keel and a pair of washers. The UAV can be equipped with a landing parachute, but it is located in the cargo hold and reduces the available volumes.
A fairly simple control system based on available components is responsible for delivering cargo to its destination. It includes satellite navigation aids and an autopilot that controls the ailerons and rudders. Remote controls are also available to allow the operator to guide the machine. Telemetry and video signal from the bow camera are transmitted to the console.
The UAV of the LG-1K type has a length of 3.2 m with a wingspan of 7.1 m. Inside the cargo compartment with a total volume of less than 0.9 cubic meters, 320 kg of payload is placed. The LG-2K glider is noticeably larger and heavier. Its length reaches 3, 9 m, the wingspan is 8, 4 m. A compartment with a volume of 1, 2 cubic meters carries 725 kg of load. The own weight of the larger vehicle is only 181 kg. During gliding, both samples develop a speed of no more than 280 km / h. The maximum gliding range is 70 miles. Aerodynamic quality - 12.
According to the customer's conditions, the UAVs of new types should be used with a wide range of transport aircraft, helicopters and tiltrotors of the ILC and the US Air Force. Depending on the type and characteristics of the carrier, the glider is transported in the cargo compartment or on an external sling.
The way of using gliders is quite simple. The carrier enters the specified area and drops the UAV in the transport position. After the drop, the glider opens its wings and begins an independent flight to the specified coordinates. There, the drone performs a horizontal landing or releases a landing parachute. After that, the "addressees" can disassemble the glider and take out the delivered cargo. Reuse is not provided.
The LG-1K and LG-2K are said to have a number of important advantages. They are simple and cheap to manufacture, and also fully cope with the assigned tasks. Gliders are compatible with multiple carriers and are capable of carrying a variety of cargoes that meet the load compartment restrictions. They also show fairly high flight characteristics and represent an extremely difficult target for enemy air defense.
Real results
The TACAD program has already reached the testing of prototypes, and the developments of the Logistic Gliders company have demonstrated some of their capabilities. The first flight tests took place in January last year. Then they ran some new tests.
In January tests, 12 UAVs of the LG-1K type were used. Half of the gliders were launched from the external suspension of the aircraft, the rest were dropped by the transport aircraft through the aft ramp. 7 flights were performed with remote control; others were carried out offline. The first tests did not provide for maximum range flights, which is why their total duration did not exceed 55 minutes. Nevertheless, it was possible to confirm all the main characteristics and capabilities of the gliders.
Until the end of the year, KMP, DARPA and Logistic Gliders conducted several more tests using different platforms and in different conditions. In December, it was reported that since the start of the tests, 18 flights with a total duration of 96 minutes were carried out. They used various carriers, up to the military transport aircraft C-130. 10 flights were performed in autonomous mode, demonstrating the required launch and landing accuracy.
New tests took place in mid-January 2020. Gliders were again dropped from aircraft and helicopters of various types. Probably, before carrying out these tests, the UAVs were improved taking into account the experience of previous activities.
Logistics and economics
According to known data, the TACAD program is still at the stage of flight tests and technical refinement. The real prospects of the presented samples from Logistic Gliders have not yet been determined. Nevertheless, the main possibilities of such a technique, the scope of its application, advantages and disadvantages are already clear.
First of all, the very approach to the design of special UAVs is interesting. Fulfilling the customer's requirements in terms of cost, the development company used the simplest and cheapest materials and components. This made it possible to obtain the required characteristics and an acceptable resource.
Gliders combine good flight characteristics, acceptable payload and good controls with two modes of operation. The flight control method, autonomous or by operator commands, can be selected depending on various factors.
The developer's statements about the high resistance of the UAV to enemy air defense systems are interesting. The small, predominantly wooden glider is difficult to spot and hit. In addition, it is unlikely to become a priority target for anti-aircraft gunners, although it will reduce the risks for its carrier.
For special tasks
In general, the Logistic Gliders company managed to create an interesting and successful specialized piece of equipment for solving specific transport problems. Tests of the two types of UAV gliders are still ongoing and the design is being improved. However, the main features of the technique have already been identified and are unlikely to change in the future.
It is to be expected that the ILC, the Air Force and DARPA will show more interest in new models and, perhaps, even bring them into service. As a result, the US Army will receive a fundamentally new means of logistics that can occupy a characteristic and important niche, reducing the risks for other transport.
However, new types of drones should not count on a large series and wide distribution. Situations in which they are needed do not occur very often - and in other conditions, well-mastered and familiar types of air transport can be used. However, this is the very case when having a highly specialized tool is better than not having one.
