Heavy Drones • Above 25kg
Optimise your system's intrinsic ground risk band
UAS over 25kg require SORA authorisation. Getting the ground risk classification right matters: a well-argued assessment can lower your iGRC by one level, directly improving your SAIL outcome and expanding what your customers can legally fly.
Compliance Foundation, Building authorisability into your UAS from the outset
Six compliance foundations, each addressing a specific dimension of the iGRC and SAIL determination. We provide the technical analysis, the documentation, and the CAA engagement to land authorisation.
Manufacturer-level compliance work that makes your UAS more authorisable, reducing the burden on every operator who flies it.
Platform Risk Profile
We establish where your platform sits in the SORA iGRC table based on its characteristic dimension and maximum speed, giving you a clear baseline risk profile before your customers begin their authorisation process.
Containment Architecture
We review your platform's geocaging, flight termination against medium robustness containment requirements, ensuring the design supports a credible containment case across the range of operational environments your customers are likely to need.
Operational Envelope Optimisation
We identify the design parameters that most directly influence your platform's intrinsic Ground Risk Class, and where adjustments to speed limits, operational altitude, or flight geometry can expand the authorised envelope available to your customers.
SAIL Profile Mapping
We map the likely SAIL level your platform will attract across realistic operational scenarios, identifying the OSO robustness requirements your customers will face and the design choices that most influence whether those requirements are achievable in practice.
iGRC Column Assessment
We review your platform's size, speed, altitude, and design parameters to establish whether a lower iGRC classification is defensible. One level down means a better SAIL outcome and stronger authorisations for your customers.
Manufacturer Compliance Package
We help develop the technical documentation, design evidence, and manufacturer-level declarations that simplify the downstream authorisation process for your customers, reducing their compliance burden and shortening the time from platform acquisition to operational deployment.
Pathway to Operational Authorisation for UAS above 25kg
Whether the brief is strategic or hands-on document drafting and CAA liaison, we shape the engagement to where you are. From technical scoping through to operational authorisation.
Step 1: Operation & Platform Assessment
We start with your platform and your intended operation, characteristic dimension, maximum speed, operational environment, and commercial objectives. This establishes where your UAS sits in the SORA iGRC table and gives you a clear picture of the compliance pathway ahead before any application work begins.
Step 2: iGRC & SAIL Optimisation
We assess whether your platform's design parameters place it in a lower iGRC column than a conservative reading suggests, working from the underlying risk calculations to determine whether a one-point GRC reduction can be legitimately argued.
Step 3: Operational Envelope Optimisation
Before the application is written, we identify the operational design decisions that most influence your SAIL outcome, including operational volume boundaries, speed restrictions, altitude limits, and population density management. Getting these right at this stage directly determines the commercial usefulness of your authorisation.
Step 4: Containment Case
We assess your platform's geocaging, flight termination, and dispersion characteristics against medium robustness containment requirements. Where gaps exist, we advise on the design changes or procedural controls needed to close them — and compile the evidence package required for RAE(F) assessment prior to CAA submission.
Step 5: Application Build
We help you develop your supporting documentation to reflect your platform, your operational environment, and the SAIL level. Every element of the application is built around your specific operation ensuring the CAA receives a coherent, evidence-based case first time.
Step 6: CAA Submission and Authorisation
We support the submission process, the CAA findings, and any clarification requests raised during assessment. The output is an Operational Authorisation that reflects the maximum flight envelope your platform and operation can support under SORA — giving your business or your customers’ the commercial reach it needs from day one.
FREQUENTLY ASKED QUESTIONS
heavy drones above 25kg. faqs
Why can't operators fly a UAS heavier than 25kg in the Open Category or under PDRA-01?
The 25kg MTOM limit is a hard regulatory boundary in both frameworks — exceed it by even 1kg and a full UK SORA Operational Authorisation is required, regardless of how benign the operation actually is.
Once a 25+kg UAS is taken through UK SORA, why is staying within SAIL II so difficult — and why does it matter?
The reason lies in the iGRC table at the heart of UK SORA's ground risk assessment. A UAS heavier than 25kg will almost always exceed the first column's thresholds of 1 metre characteristic dimension and 25m/s maximum speed, placing it immediately into the 3m column or beyond. That shift alone pushes the intrinsic GRC upward by at least one point across every population density band.
What role does an RAE(F) play?
The RAE(F) performs the expert technical evaluation that informs the CAA's decision to issue the certificate for specific SORA design requirements.
The CAA requires their review for:
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M1A Strategic mitigation – sheltering if UAS >25kg
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M2 Effects of UA impact dynamics are reduced
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Containment requirements at medium or high robustness
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Tethered containment requirements
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SAIL3-6