The latest hit in the world of aviation, the rotorcraft, legally known as "multirotor", charged and conquered the civilian market and has established itself as a fait accompli, gaining headlines in the context of "near-miss" safety incidents involving passenger aircraft or the banning of flights over the venue of a celebrity wedding.
Contrary to this phenomenon, however, the rotorcraft world is still searching for a path into the security and military market. Apparently, the civilian breakthrough established a technological reality that made rotorcraft accessible to everyone. On the other hand, however, it created a misrepresentation and a gap of unrealistic expectations regarding the simplicity of converting this technology into a readily available and reliable operational weapon system. This gap, reflected through such force build-up and employment derivatives as mission categories and personnel background and proficiency, pertains to such key questions as the missions for which rotorcraft are suitable and the skills required in order to fly them. Should the multirotor systems be regarded as "hovering binoculars" or as unmanned airborne vehicles? Should the rotorcraft be regarded as a trooper's personal video kit or as a dedicated weapon system operated by teams trained specifically for this mission and, naturally – are there any lessons that may be learned from experienced sources?
As far as the legal aspect is concerned, simple and clear-cut answers may be provided to these questions, as a rotorcraft is an unmanned airborne vehicle, but we face more substantial questions that pertain to the operational solution and to the consolidation of an operating concept, which require in-depth deliberation and professional understanding of the field.
Technological Advantages & Disadvantages
The basic theory of operation of multirotor platforms is staying airborne on the basis of physical principles (motor power that lifts mass into the air) rather than on the basis of aeronautical principles (lift) like fixed-wing aircraft (each rotorcraft has several arms with a motor and rotor rotating at a very high speed at the tip of each arm). The primary implication of this theory of operation is a zero-sum game over the carrying capacity of the platform – between endurance (battery power) and mission capacity characteristics (payloads, communications, flight range, etc.).
This theory of operation has other significant derivatives of which we should be aware – when the battery has run out of power, the platform will drop from the sky to the ground rather than glide to the ground like an aircraft. Additionally, during the descent process prior to landing, the battery will consume the same amount of energy it consumed during the climbing process, while with aircraft it is a known fact that the descent process is a fairly economical phase. The direct derivative of these facts is the need for a high level of operating proficiency for extended flights and especially with regard to processes where the ground station cannot maintain visual contact (line of sight) with the platform in the air, or, in other words – limited endurance and short range. Other aspects that stem from this theory of operation are stealth deficiencies owing to the loud noise generated by the rotors which rotate at a high speed, sensitivity to weather conditions, especially to winds close to the ground, and a real risk to human life as a result of a strike by the rotors – even on the ground.
However, the theory of operation outlined above, combined with an advanced and miniaturized flight control capability which is the very core of the rotorcraft technology offer significant advantages over other systems: the automatic take-off and landing capability which enables the platform to take off vertically from a given point ensures the simplicity of launching the sortie, even with a relatively limited operating proficiency. The ability to hover enables the platform to "stop in mid-air". This ability is combined with a payload stabilizer (gimbal) system which absorbs and dampens the vibrations of the platform and stabilizes the image. Another advantage is the simplicity of adapting payloads to the platform and balancing its center of gravity.
We should bear in mind another significant restriction that currently exists in civilian rotorcraft systems – the total dependence on GPS. Unless it receives the GPS signal, the rotorcraft cannot operate. These characteristics led the civilian rotorcraft world, which focuses on the masses of amateur operators, to develop systems that are as automatic as possible with no backup elements, which can normally remain airborne for about twenty minutes, while carrying small, high-quality daytime surveillance payloads to ranges of several hundred meters at a low level. These systems are easy to maintain on the basis of component replacement, and are supported by basic ground stations.
While considering the theory of operation and the evolving technological trends, we should bear in mind that intensive activity is under way in an attempt to enhance the technological capabilities of rotorcraft platforms, mainly by such giant corporations as Amazon, Facebook and Google, who believe that this platform category possesses a truly revolutionary potential. However, they hardly pertain to the adaptation of these systems to the challenges of the dynamic battlefield.
The Operational Need
The asymmetrical operational environment led to a change in the operational center of gravity with the emphasis placed on intelligence and in particular on the spotting of the "disappearing enemy" in both urban and open areas. All hierarchical levels, from the supreme command to the field echelons, are involved in force build-up and employment aspects with the emphasis placed on this task. UAV systems have been found, worldwide, to be one of the best-suited solutions for this task, especially owing to their ability to transmit real-time intelligence to the network systems, while remaining, covertly, over the area of interest for long periods of time, as required from intelligence missions. As they constitute real-time UAV systems, rotorcraft platforms are perceived as possessing the potential for being used on the battlefield to provide assistance to the ground forces. Without a doubt, their ability to take off and land automatically, vertically and from the field, combined with their ability to hover, call for this measure to be included in the mission toolbox available to the battalion commander.
We should clearly distinguish between two variables – mission complexity and operating (flying) complexity. Generally, all real-time video/surveillance missions may be characterized by a high degree of mission complexity, especially when they are flown at a low level and in the context of an intensive operational profile. The interpretation and decision-making requirements in a mission flown from the field at a flight level of 100 meters are normally much more complex than those in a high-level mission involving a mission control trailer, such as the trailers of the larger UAV systems.
Maintaining visual contact/continuity with a target while flying at a low level, under conditions of masking by buildings, despite the hovering capability, is sometimes more difficult than it is when using other UAV systems. Additionally, the number of targets/distractions that exist in the context of low-level missions is much higher than the number of such elements in high-level missions. Consequently, the operators of rotorcraft systems are required to possess a high level of mission proficiency. If we add the implications of flying rotorcraft systems in an operational environment, we will realize that a high level of operating proficiency is required even at the planning stage, as flying at a low level and within a range of several kilometers is a highly complex challenge, especially in urban areas, for a small system with a very limited endurance.
At the same time, missions that do not require real-time decision making, flying within close ranges (line of sight) and for short periods of time, with no need for covert operation and normally during the daytime can be accomplished even with the operators possessing a lower level of proficiency. Some of these missions may even be accomplished using the systems currently available on the market. However, even when the mission characteristics are as outlined, it is recommended that the operators possess the operational proficiency of professionals rather than that of amateurs, so that they may accomplish the required operational objectives.
In addition to the "micro" aspects of system operation, the systemic aspects should be viewed through a wider perspective. That perspective covers a large number of systems, personnel training, system maintenance and the chain of supply necessitated by the need for operational serviceability and availability, as well as other aspects.
Lessons may be derived from two similar past cases where UAV systems were introduced and employed for land missions. The first case involves the assimilation of the "Rokhev Shamayim/Sky Rider" (Skylark I) system by the IDF Ground Forces HQ, and the other involves the operational concept of the Raven systems used by the US Army (which is even more relevant than the first case). In both cases the systems were regarded as airborne systems from the moment they were introduced and are handled subject to the characteristics of aircraft to all intents and purposes. With regard to the systemic aspect, the concept is one of centralized control that was decentralized and delegated to the end units, by skilled professional teams that were trained as warfighters and UAV operators. In the American case, characteristics that are similar to those of the rotorcraft field may be identified, as the systems in question resemble the rotorcraft systems in their performance characteristics and are available in the thousands. One of the primary lessons we can adopt from the operating concept of the Raven system is the clear-cut definition and strict observance of an envelope of close, short missions (rather than stretching the capabilities of the system to the limit, as is the normal approach in Israel). The rotorcraft field offers a real opportunity for providing an important, vital operational capability to the ground forces, but it requires a clear, professional diagnosis regarding the capabilities that may be adopted from the civilian market as opposed to those that are not suitable for the military environment.
At the same time, a substantial expectation gap exists with regard to the capabilities of the rotorcraft systems in the military environment. This gap stems primarily from the extensive attention and focus on the civilian activity and from the fact that it is so readily accessible as a hobby. The employment of rotorcraft systems in military missions, especially in real-time video/surveillance missions, currently necessitates a high level of mission proficiency and personal professionalism. This issue should be addressed through two efforts. One is personnel recruitment sources and training, and the other is substantial investment in the development of mission-oriented system capabilities that would ease the proficiency requirements. A systemic operational concept should be specified for the rotorcraft field that would reflect the advantages of the rotorcraft platforms vis-à-vis the challenges they present. For example, maintaining the principle of simplified maintenance by the field echelons, along with strict observance of structured, methodical maintenance. All relevant efforts and activities must be coordinated with the IAF authorities, as the rotorcraft platforms operate within the national airspace.
The tendency toward having the missions normally assigned to Mini UAVs assigned instead to the rotorcraft platforms should be avoided, and it is recommended that the proper combination between the two activities should be sought. Proper employment and intelligent operational use will maximize the advantages of each system category.
It is recommended that the UAV centers that are already active within the defense establishment be relied upon, as they possess the most extensive experience in UAV system operation and force build up.
It is recommended that the professional and regulatory insights, as learned by the aviation authorities in the world and particularly in Israel be studied carefully and thoroughly. An effort should be initiated to find a model for cooperation between the military authorities and the civilian industries (not necessarily the defense industries), the academic centers and the licensing authorities, which constitute the technological and conceptual locomotives of this activity.
However, the task of developing the operational capabilities should be assigned to the defense industries, as their world enables them to understand the operational challenges and develop and supply systems that are relevant to the battlefield. For this purpose, the defense establishment should set forth a business model that is suitable for the development and acquisition of rotorcraft systems. Without such a model, the market of rotorcraft systems for military applications will never leave the ground.
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