Airspace change post implementation reviews

• We determine the scope and objectives of the review after discussion with the airspace change sponsor. This may include:
  
  • A review of what was to be achieved by the change
  • Air traffic control/management requirements (safety, delay, capacity efficiencies)
  • Military air traffic control/management requirements (if applicable)
  • Environmental conclusions
  • Effectiveness of the change
  • Other benefits or impacts
  • Operational impact via feedback gathered from all affected aviation stakeholders
  • A post implementation safety analysis.
• We identify and confirm the data required from the change sponsor by sending them a data request form which will include the data collection period and expected submission date.
• We may, during our assessment phase, revise the scope and objectives of the review.
• We may request further information from the change sponsor at any time prior to publication of the report.

1. Change sponsor gathers data and operational feedback and information from stakeholders during the data collection period (normally 12 months).
2. Change sponsor submits data to us.

1. We assess the completeness and adequacy of the data submitted.
2. Where applicable we independently gather aviation stakeholder feedback.
3. Where applicable we log and analyse written feedback from people and organisations other than airlines, other aircraft operators, airport operators and air navigation service providers.
4. We assess the operational and environmental impact of the change against the expected impact.
5. We consider and determine any appropriate consequential action.

1. The change sponsor can provide comments.
2. The report is published on our website.

The following outcomes may result from the post implementation review:

• the CAA may confirm that the implemented design satisfactorily meets – within acceptable tolerance limits - the objectives and approval terms and the airspace change is confirmed; or  
•  the CAA may determine that the implemented design does not satisfactorily achieve the objective and terms of the CAA’s approval, and modifications are not practicable. In any such case, the change sponsor may be required to revert to the previous airspace design.
• the CAA may require modifications to better achieve the objective and terms of the CAA’s approval. Once the modifications are implemented and operated for a period (approximately six months), there are three further possible outcomes:
  • the CAA may conclude the modifications did not better achieve the objective and terms of the CAA’s approval, and that the original design was satisfactory and confirm the original airspace change; or
  • the CAA may find the modifications did not better achieve the objective and approval and may conclude that the original design was not satisfactory, and the original airspace change is not confirmed.  To pursue its airspace change, the change sponsor will need to start a new airspace change proposal; or
  • the CAA may conclude that the modifications do better achieve – within acceptable tolerance limits – the objective and approval terms and the modified design will be confirmed.

Where a post implementation review is required, the change sponsor will monitor and gather data on the impacts of the airspace change. For Level 1 airspace changes, this includes collating and responding to stakeholder feedback from the date of implementation.

For Level 2 and 3 airspace change proposals where the CAA has determined that it would be proportionate to undertake a post implementation review, we will provide the change sponsor with a ‘data request form’, clearly setting out the data that is required to enable the completion of it.

Around one year after implementation, the sponsor is required to publish its data submission on the airspace change portal. After publication, there will be a 28-day feedback window. The CAA can extend this period if it considers it proportionate to do, for example, if a review of the initial data set shows that further data is required, the feedback window may be extended to allow for responses to the new data. The CAA will consider this feedback in its post-implementation review. 

Not all airspace change proposals that have taken plan have a post implementation review. 

A post implementation review must be completed for all Level 1 airspace change proposals. It will only be completed for Level 2 and Level 3 airspace change proposal when the CAA determines that it is proportionate to do so.

Where a post implementation review is required, the CAA may proportionately reduce the extent of evidence and data required from the change sponsor. The CAA will provide the change sponsor with a ‘data request form’ at the end of stage 6 of the CAP1616 process, clearly setting out the data that is required to enable the completion of the post implementation review. The data request form will be published on the airspace change portal during Stage 6.

The post implementation review is not a public consultation or re-consultation, it is a part of the CAP 1616 airspace change process and takes place at Stage 7. If the airspace change proposal requires a public consultation, this will have taken place at Stage 3 of the CAP 1616 airspace change process.  

The change sponsor must begin monitoring and gathering data on the impacts of the airspace change as soon as it is implemented, and respond to stakeholder feedback received, keeping a record of any interactions. This includes the impacts on airspace users and those on the ground affected by aviation noise or other environmental factors.

The post implementation review stage is where the change sponsor analyses the data and feedback they have gathered in order to answer the questions asked by the CAA, before submitting a report to the CAA and publishing it on the airspace change portal.

After publication, there will be a 28-day feedback window. During this time any stakeholder can provide feedback on the change sponsor’s data, and how the airspace change has actually performed while considering what was expected, i.e. the intent of the change. The CAA can extend this window if it considers it proportionate to do, for example, if a review of the initial data set shows that further data is required, the feedback window may be extended to allow for responses to the new data. The CAA will take account of this feedback in its post-implementation review.

The CAA usually initiates the post implementation review 12 months after the airspace change is implemented, for permanent airspace changes that are required to undertake a post implementation review. This is to ensure that a full cycle of winter and summer operations has been observed in all weather and air traffic conditions. However, if a change sponsor, or another stakeholder, makes a representation that a different period is needed to collect more representative data, the CAA will consider an extension. For example, this might be because the route that was the subject of the airspace change has been used infrequently and an extended period would allow for a more representative data sample with a wider range of weather conditions.

The CAA may also initiate a review at any other time post implementation if it considers this is appropriate to do so. This can be a review of specific elements of the airspace change, not necessarily fulfilling the standard post implementation review requirements in time or scale.

The amount of time required by the CAA to review the evidence and publish its conclusions on the post implementation review will depend on the level and quality of data submitted by the change sponsor. While it may be possible for us to complete this work within three months of the change sponsor’s data submission being published on the airspace change portal, we may need additional time for the following reasons:

• where there is a very high volume of stakeholder feedback to the published data
• where the CAA’s initial assessment of this data leads us to ask for additional data from the change sponsor
•  where the outcome of the review is that design modifications are required, in which case the timescales could be extended significantly depending on the extent of any redesign.