CAP3040 Fourth Edition: CAA Adds a Route to Scale BVLOS AAE Operations Across Multiple Sites

The UK Civil Aviation Authority has published the fourth edition of CAP3040, its policy concept for Beyond Visual Line of Sight operations in an Atypical Air Environment.

The main addition is a new Annex G, which sets out a pathway for experienced operators to carry out equivalent AAE operations across multiple sites under one Operational Authorisation, without the CAA carrying out a full assessment of every additional location.

The fourth edition is current from 29th September 2026. The CAA describes the rest of the update as minor corrections to the main policy text.

For organisations carrying out repeat BVLOS inspection work, such as railway, powerline or similar infrastructure operations, Annex G is an important development. It starts to address one of the practical problems with scaling AAE operations: proving essentially the same operation again each time the location changes.

It is not a general permission to operate BVLOS anywhere. The operator still needs an AAE-based Operational Authorisation, suitable experience and organisational capability, and each additional site still needs its own risk assessment and airspace checks.

What is an Atypical Air Environment?

An Atypical Air Environment, usually shortened to AAE, is an area where the CAA accepts that conventionally piloted aircraft are expected to be much less likely to operate because of the close proximity of particular ground infrastructure.

CAP3040 gives examples including:

within 100 ft of a building or structure;
within 50 ft of a permanent above-ground linear structure, such as a railway, road or powerline;
within the boundary of private property, at a height not exceeding 50 ft.

Those examples are not automatic permissions or fixed legal definitions. An applicant still has to explain why the proposed area should be treated as an AAE and show how the remaining air risk will be managed.

AAE operations can be useful for BVLOS because operating very close to infrastructure can reduce the likelihood of encountering a conventionally piloted aircraft.

The CAA is also clear that an AAE is not a separate class of airspace and cannot be assumed to be free of other aircraft. Emergency services, military aircraft, infrastructure owners and general aviation can still operate at low level.

An operator therefore still needs appropriate mitigations and an Operational Authorisation.

Where CAP3040 fits into UK SORA

CAP3040 is supporting policy for Specific Category BVLOS operations.

An operator does not obtain permission to fly simply by meeting CAP3040. The operation still needs to be assessed through the appropriate Specific Category route, normally through a UK SORA-based Operational Authorisation where UK SORA applies.

The operator defines the proposed operation, its operational volume, ground and air risks, mitigations and procedures. CAP3040 then provides the CAA's current policy for how the air-risk side of an AAE operation may be approached.

The policy includes subjects such as:

pre-tactical notification of the route or area of operation;
coordination with other local airspace users;
electronic conspicuity;
operations in controlled airspace;
high-intensity anti-collision lighting;
containment;
collision avoidance;
remote pilot competence.

The fourth edition keeps that overall structure but adds a route for suitable operators to scale equivalent operations to further sites.

The problem with scaling AAE operations

Before Annex G, CAP3040 already recognised that more than one operational volume could legally sit within one Operational Authorisation.

The practical difficulty was that each AAE is tied closely to its location and surrounding infrastructure.

A railway section in one part of the country may have different nearby aerodromes, helicopter activity, restricted airspace, terrain or local aviation users from another railway section. Even where the operational method is essentially the same, the safety case cannot simply assume that every site presents the same risk.

That is why the CAA has generally expected separate procedures and safety arguments for individual AAE volumes.

Annex G creates a route for moving beyond that site-by-site assessment model once an operator has enough experience and can show that the additional locations do not change the approved safety case.

What Annex G changes

Annex G is called Pathway to Equivalent Operations Across Multiple Sites.

It allows the CAA to consider amending an existing AAE Operational Authorisation so that an operator can conduct equivalent operations at additional locations.

The key word is equivalent.

For the new route to apply, the additional operation must not:

increase the overall risk profile;
require an existing mitigation to be changed;
require new mitigations to be introduced;
alter the assumptions supporting the approved safety case.

If those conditions are met, the operation may be able to take place under the existing Operational Authorisation, subject to the conditions set by the CAA and the process in Annex G.

If the change goes beyond that and becomes a major variation, the normal major variation or new UK SORA application route still applies.

It is a phased pathway

Annex G does not suggest that a new operator can obtain one AAE authorisation and immediately roll it out nationally.

The CAA describes a phased route.

The first stage is the initial AAE Operational Authorisation. The operator develops the operation, safety case and procedures for the first site and is encouraged to engage with the CAA before submitting the application.

The next stage is expansion to additional sites with full CAA assessment. The operator can use the normal variation process, providing the site-specific information, risk assessment and evidence needed for the CAA to assess the new location.

Only after the operator has built sufficient operational experience, organisational capability and safety performance does the new multiple-site pathway become relevant.

At that point, the operator can discuss an equivalent-operations condition with the CAA. If the CAA is satisfied, the Operational Authorisation may be amended so that further equivalent sites can be added through the Annex G notification process instead of receiving a complete assessment each time.

This means Annex G is aimed at mature operators that are ready to scale a proven operation, not operators trying to avoid the normal assessment of an initial AAE concept.

Who can use the multiple-site pathway?

CAP3040 sets a number of minimum expectations.

The organisation must be an established UAS operator with demonstrable AAE experience and hold a valid AAE Operational Authorisation.

It must also have suitable safety-critical roles and be able to demonstrate organisational competence and capability.

CAP3040 gives the Accountable Manager as an example and makes an important point about independence: the person carrying out a risk assessment for a particular operation cannot also be responsible for signing off that risk assessment.

The CAA notes that a Safety Management System is not mandated for operations below SAIL IV, but says a documented organisational structure identifying safety-critical personnel and responsibilities would normally be appropriate.

Additional locations must also be equivalent in nature and fall within the organisation's operational specialism. CAP3040 gives examples such as keeping railway operations with railway infrastructure, or powerline operations with similar power infrastructure.

Each new site still needs its own risk assessment

The multiple-site pathway does not turn an Operational Authorisation into a blanket geographical permission.

The operator remains responsible for assessing every additional location.

For each site, CAP3040 requires a suitable and sufficient risk assessment together with the agreed supporting AAE documentation. The operator must also provide location information, such as KML or KMZ files, and submit an Airspace Assessment Checklist.

The important change is in how the CAA handles that material.

The documents will be retained for oversight, but the CAA says they will not routinely be assessed individually on receipt or listed separately in the Operational Authorisation.

That transfers more responsibility to the operator to decide whether each new location genuinely stays inside the approved safety case.

The CAA can then use auditing, sampling and targeted assessment to check how that responsibility is being exercised.

The new Airspace Assessment Checklist

Annex G includes an Airspace Assessment Checklist for additional locations.

The checklist requires the operator to assess the airspace around the proposed operational volumes and consider nearby aviation activity which could affect the AAE argument.

CAP3040 requires an assessment extending 5 NM around all operational volumes.

The mandatory checks include subjects such as:

licensed, certificated, minor and military aerodromes;
Military Aerodrome Traffic Zones;
restricted, prohibited and danger areas;
controlled airspace;
instrument flight procedures;
military exercise and training areas;
other potentially hazardous aviation activity;
NOTAMs;
gliding, microlight and other sporting or recreational aviation sites.

The checklist also recommends using historical ADS-B or airspace-analysis tools for additional situational awareness. CAP3040 warns that an absence of low-level ADS-B data does not prove that aircraft do not use the area.

This is important because the basis of an AAE is reduced encounter risk. The operator still has to understand the aviation environment around each new site rather than assuming that similar infrastructure means identical air risk.

Notification before operations start

Once an operator has the equivalent-operations condition on its Operational Authorisation, each new site goes through a notification process.

The operator must submit the site's risk assessment and completed Airspace Assessment Checklist to the CAA through ACOMS with the NOTAM request.

Unless the CAA agrees otherwise, the notification should be submitted at least five working days before the required publication of the NOTAM.

The CAA uses that notification to carry out airspace deconfliction checks and, where required, review the checklist or confirm that the proposed volume remains within the scope of the existing authorisation.

The operator cannot begin flying until the active period of the NOTAM starts.

The CAA is explicit that it does not approve the Airspace Assessment Checklist and that the notification process is not a full assessment of the proposed operational volume.

Responsibility for deciding whether the site is suitable and the existing safety case remains valid stays with the operator.

How the CAA will oversee scaled operations

Moving away from a full CAA assessment for every site does not mean the CAA steps away from oversight.

Annex G allows the regulator to apply an enhanced assurance regime based on the size and complexity of the operation.

That may include:

audits of the operator's processes and procedures;
sampling of additional operating locations;
review of site-specific risk assessments;
targeted assessments of the organisation's ability to identify and operate safely within additional AAE volumes.

The level of oversight can be adjusted according to the operator's performance, maturity and compliance record.

This is a different regulatory model from approving every site individually. The CAA is placing more reliance on a proven organisation's own processes, then checking those processes through risk-based oversight.

What has not changed

The fourth edition does not make AAE BVLOS generally available.

Operators still need a valid Operational Authorisation and must stay within its conditions.

An AAE is still location-specific and has to be justified. The operator still needs to account for other airspace users, obtain any separate airspace permissions that apply and manage the ground risk as part of the wider UK SORA assessment.

The usual AAE mitigations also remain relevant. CAP3040 continues to address NOTAMs or other pre-tactical notification, electronic conspicuity, coordination with local aviation users, anti-collision lighting and robust containment.

The new pathway only changes how suitable operators may scale an already-established type of AAE operation across equivalent sites.

Annexes E and F are still to come

The fourth edition also shows where CAP3040 is expected to develop next.

Annex E, covering power transmission and distribution networks, remains work in progress.

Annex F, covering agriculture, also remains work in progress.

CAP3040 says both are expected to be published in Edition 5.

That means the current multiple-site pathway is available before the CAA has finished developing sector-specific AAE guidance for all of the infrastructure and operating environments it expects the policy to cover.

What this means for BVLOS operators

For an operator proving a one-off BVLOS operation, the fourth edition does not fundamentally change the starting point.

The more significant effect is for organisations trying to turn a successful AAE operation into a repeatable service.

An infrastructure operator or UAS service provider may have dozens or hundreds of similar assets. Requiring a complete regulatory assessment every time essentially the same operation moves to another equivalent site limits how efficiently that operation can scale.

Annex G gives the CAA a way to move from assessing each location in full towards assessing whether the operator itself has the competence, governance and processes to add equivalent locations safely.

The operator takes on more responsibility in return.

That is why the pathway requires experience, organisational capability, individual site risk assessments, formal airspace checks, advance notification and continuing CAA oversight.

The fourth edition of CAP3040 is available from the CAA. The CAA also provides a simpler introduction to operating within an Atypical Air Environment.