# BVLOS Unmanned Aircraft Operations in Forest Environments
## 4 The International Regulatory Environment  
One of the biggest issues when planning a BVLOS operation is that the applicable rules and regulations vary markedly between countries [20]. To this effect, the ability to conduct BVLOS operations and under what conditions are not standardised. This issue is briefly explored in this section, with some of the commonalities highlighted. The next section deals with taking a risk-based approach, which may not match a particular set of rules, but it instead highlights how risks can be managed. For manned aviation, it is somewhat more straightforward as to how regulations are typically created. The International Civil Aviation Organisation (ICAO) would typically create Standards and Recommended Practices (SARPs), which would then be used by signatory states to create rules that are fit for purpose for their country, registering any differences against the SARPs [25]. However, these have not yet been produced for remotely piloted aircraft systems or autonomous unmanned aircraft systems. While there may not be SARPs, there are model regulations that are available for states to use and adapt for their own countries [26]. These model regulations have relatively few discrepancies between high-level regulatory considerations that are used in major jurisdictions [27]. Under the model regulations, BVLOS operations would need to be conducted by an organisation that has achieved certification under Part 102 of the Civil Aviation Rules (CARs). The model CAR Part 102 provides a process whereby an organisation would submit an operating manual--commonly called an exposition--to take a risk-based approach to achieving variations to CAR Part 101, which is a set of general operating rules and is more constrained in what operations can be done [28]. In the accompanying Advisory Circular (AC), AC102-1, which details acceptable means of compliance with CAR Part  
Figure 4: Example of the operating area in Scenario 2 (Hard BVLOS), a circa 6000 ha forest estate in steep terrain. The yellow cross indicates the proposed take-off location. 102, ICAO states that the \"risks associated with BVLOS will require a strong safety case in your application\" (p. 11) [29]. Examples contained within the AC include explaining how airspace requirements will be met, the ability to provide separation from other aircraft, and the means of mitigating risks to persons, property, and terrain [29]. While these requirements are common across most countries, the means of determining how airspace requirements are met, how separation is achieved, and how risks are managed are where discrepancies between countries tend to occur. For the first two aspects--complying with airspace requirements and maintaining separation from other aircraft--there may be several ways of achieving these requirements for a BVLOS operation. While the airspace classes and types of special use airspace that are used by each country do vary, the underlying requirements for those that are used are similar and sometimes identical. Typically, forest environments are not collocated with large cities or busy airports. For that reason, BVLOS forestry operations usually happen in Class G airspace, which is uncontrolled airspace. Regulators emphasise that operation within Class G airspace is dependent upon the'see, detect, and avoid' principle, as per the Visual Flight Rules (VFRs) [30; 31]. For this reason, there are associated rules regarding visibility, height above terrain, and distance from clouds such that pilots can visually detect other aircraft, as well as the requirement to keep a listening watch on the radio for position reports of other aircraft [30; 31]. In this sense, unmanned aircraft operators are expected to maintain VLOS with their aircraft and surrounding airspace or to use EVLOS and achieve the same standard with the assistance of visual observers.