This article explores the key aspects of PDRAs, their advantages, and how they compare to Standard Scenarios (STS) and the Specific Operations Risk Assessment (SORA). It also outlines the application process for PDRAs and discusses their potential for expansion in the future.
What is a PDRA?
A Predefined Risk Assessment (PDRA) is a European-based operational scenario that has been cleared as an acceptable means of compliance (AMC) by EASA. JARUS also proposes PDRAs which can be used by any competent authority including EASA or other national aviation authorities outside Europe. Each published PDRA has undergone a risk assessment by EASA and, upon completion as an AMC, has been added to Article 11 of Regulation (EU) 2019/947.
The provisions and mitigations in the current PDRAs have been detailed to be more generic than, for example, the European Standard Scenarios (STSs). This has been done to allow operators and competent authorities to establish more prescriptive limitations and include more material specific to the operation. There are currently 5 published PDRAs detailed in the figure below:
PDRA-S01 is suitable for inspection or short-range cargo operations. It allows operations in VLOS, with a height restriction of 120m, with the exception of up to 150m to clear an obstacle, or with a defined risk buffer to protect third parties. The UAS must have a maximum characteristic dimension of less than 3m. The operation can be performed in an urban environment; however, no uninvolved persons are allowed to be present during the operation in the controlled ground area.
PDRA-S02 is ideal for surveillance, agricultural or short-range cargo operations. It allows for BVLOS operations of up to 1km or 2km with the presence of airspace observer/s. The UAS should have a maximum take-off mass of less than 25kg, including its payload, a maximum characteristic dimension of less than 3m and a maximum ground speed of 50m/s. The flight height is limited to 120 m or up to 150 m to clear an obstacle or with a defined risk buffer to protect third parties. The mission can only be conducted in a sparsely populated area, and no uninvolved persons are allowed in the controlled ground area.
PDRA-G01 is optimal for surveillance or long-range cargo operations. It can fly BVLOS in a sparsely populated area of up to 1km or 2km with the presence of airspace observers within uncontrolled airspace below 120m or 150m (with a defined risk buffer or to avoid an obstacle). The UAS must have a maximum characteristic dimension of 3m and a typical kinetic energy of up to 34kJ.
PDRA-G02 is available for all types of operations. It can fly BVLOS in the range of a direct C2 link (radio line of sight) in reserved/segregated airspace in a sparsely populated area. The UAS must have a maximum characteristic dimension of 3m and a typical kinetic energy of up to 34kJ.
PDRA-G03 is applicable for linear inspections or agricultural operations. It can fly BVLOS in the range of a C2 link in either controlled or uncontrolled airspace. The maximum flight geography is 30m or close to objects in a sparsely populated environment. The UAS must have a maximum characteristic dimension of up to 3m and a typical kinetic energy of up to 34kJ.
What are the Benefits of a PDRA?
An operation that meets the requirements for a specific PDRA has many benefits to the operator. The path has been clearly defined for operators, where they can follow the established risk assessment, based on a table of numerous declarations. Advantages such as a simplified authorisation process, accelerated approval times, predefined risk mitigations and regulatory compliance can aid in deciding whether to apply a PDRA.
Since EASA has already conducted risk assessments for the existing PDRAs, the operation under a specific PDRA can be authorised without a full risk analysis or the need for SORA to be performed by the operator. This not only simplifies the authorisation process, but it can also speed up the authorisation process and reduce the administrative burden on both the operator and the aviation authority.
These PDRAs also ensure regulatory compliance, have met the requirements for Article 11 of Regulation (EU) 2019/947 and have predefined mitigation measures to enhance safety. This enables the organisation preparing the drone mission to focus their financial, time and project resources in other areas.
By using a PDRA, the operator is focused on one type of operation which has been developed specifically for that flight use case which provides clear guidance to the operator.
What is the Difference Between SORA, STS and PDRA?
The methodology for conducting an operational risk assessment, found in Guidance Material 1 (GM1) Acceptable Means of Compliance (AMC1) Article 11, requires a specific operations risk assessment (SORA). SORA was developed by JARUS WG-6, with Lorenzo Murzilli leading the group at the time. The process evaluates which SAIL level the operation will be classified as and what safety risks must be mitigated for it to be safely conducted. However, there are several alternate means of compliance (MoC), such as a standard scenario (STS) or a PDRA, which have been pre-approved by EASA and do not require a full SORA exercise.
There are currently 2 published European STS:
STS-01 VLOS over a controlled ground area in a populated environment
and
STS-02 BVLOS with Airspace Observers over a sparsely populated environment
For more on STS, check out Murzilli Consulting’s Guide to STS.
The 2 European STS have similar requirements to that of PDRA S01 and S02. The main difference is that an STS has clear limitations, in particular with the type of drone each STS can use (STS-01 can only operate with a drone bearing a C5 class marking and STS-02 only with a drone bearing a C6 class marking).
A PDRA, on the other hand, has more flexibility, allowing operators and NAAs to establish mitigations and limitations relative to the intended mission. There are currently 2 types of PDRAs; PDRA’s which have the letter G (PDRA-G01, G02, G03), to mean generic and PDRA’s which have the letter the S (PDRA-S01 and S02), which means that they have been derived from an STS.
How to Apply for a PDRA
The overall process for applying for an operational authorisation using a PDRA is relatively straightforward. It requires the operator to fill out the application form and the relevant PDRA table (both of which can be found on EASA’s website) and complete an operation manual. The completed PDRA application can be submitted to the relevant NAA for operational authorisation.
While the process is straightforward, details such as defining risk buffers, ensuring the operation is applicable to the PDRA and demonstrating integrity and proof can be complex without expert support such as that from a drone consulting firm.
Applicants using a drone consulting organisation will benefit from faster timelines, direct strategy for regulatory compliance, documentation preparation, and gap analysis to highlight areas that need to be expanded on, such as training, safety, and risk assessment. Murzilli Consulting’s custom-made services include Aviation Authority Liaison, Design Verification Report (DVR), Light UAS Operator (LUC) in Europe, Operational Authorisations (SORA) and Regulatory Strategy have been designed to ease the overall operational authorisation process to accomplish clear results.
Are there any PDRA Advantages for LUC Holders?
Among the privileges of an LUC holder, there is one advantage that is relevant to PDRAs, according to AMC 1 UAS.LUC.060, a LUC holder can authorise operations carried out by the operator and covered by a PDRA without requesting an authorisation. This means that after the PDRA application has been approved by the relevant authority, the LUC holder can authorise the mission without further engagement with the authority. Alternatively, if the LUC specifically says that the holder can self-approve PDRA missions, then they do not need additional approval.
For more on LUC, take a look at Murzilli Consulting’s Guide to LUC.
Will There Be Any Additional PDRAs in the Future?
EASA’s website encourages users to propose suggestions for PDRAs. The authority is motivated to publish new or at least make amendments to the existing PDRAs. This goal is to enable as many operators as possible to use PDRAs and support the expansion of the European drone industry.
With the support of JARUS, there are currently several PDRAs under evaluation. The following 4 are some of the PDRAs currently in-work, although there are several others that have not yet been announced for public discussion.
Murzilli Consulting offers a wide range of services that can support organisations considering operations using a PDRA. For a full list of our services, click here, or write to us, and we would be happy to answer any questions.
