Proposals to take forward the NATS Independent Enquiry recommendations with regards to resilience

Closed 21 Apr 2017

Opened 24 Feb 2017


The main consultation document sets out the outcome of work carried out jointly by the Civil Aviation Authority (CAA) and NATS with regards to NATS’ resilience and seeks views on a proposed enforcement tool and a new licence condition.

We are proposing to adopt specified definitions of resilience, contingency and business continuity and to set the requirements for the enforcement of these under the NERL licence so that the CAA can have greater assurance that NATS is taking all reasonable steps to minimise and manage disruption.

It also includes our proposals for a new licence condition that will require NATS to consult on and submit a resilience plan setting out how it will comply with its licence obligations.

Why your views matter

On 12 December 2014 a disruption in NATS en route air traffic services caused 14,863 minutes of NATS attributable delay. This followed a more severe disruption on 7 December 2013 which caused 137,225 minutes of NATS atributable delay. The 2014 disruption led us to set up an Independent Enquiry led by Sir Robert Walmsley to review the circumstances around the events of that day, including addressing the levels of future resilience and service delivery that should be expected across the en route air traffic network, taking into account relevant aviation benchmarks and costs.

In both incidents, we found it difficult to answer the question as to whether NATS was compliant with the requirements of its licence to meet a reasonable level of demand on a continuing basis. This is because, although the regulatory framework clearly envisages some disruption in service to ensure the safety of aircraft, we had no formal view on what level of disruption should be considered to be acceptable.

We accepted that NATS had taken a number of steps to recover each time quickly and safely, that it had maintained good communications with its customers and had taken steps to minimise the impact of the disruption such as offering alternative routing. However, we did not consider that the licence obligations were clear enough to effectively hold NATS to account should we find that NATS’s policies, plans and procedures were inadequate to properly minimise the risk of disruption or to manage an efficient and effective recovery, in line with its statutory duties and licence obligations. The Independent Enquiry report did not find that there had been deficiencies in NATS’s actions in this regard but accepted our concerns about better oversight and assurance in the future.

The Independent Enquiry therefore recommended that we and NATS jointly develop and agree definitions of resilience, contingency and business continuity to be used in the context of air traffic control in the UK and a methodology for determining acceptable levels of disruption to give greater clarity. It also recommended that we include a new condition in the licence requiring NATS to submit a resilience plan to us for our approval.

What happens next

Once we have considered your comments we will decide what modifications we propose to make to NERL’s licence and to our policy on the enforcement of the licence. Licence modifications will require another short consultation under section 11 of the TA00 which we will publish shortly after this consultation closes, with details of the changes we are making to our enforcement policy.


  • Workshop

    From 21 Mar 2017 at 09:00 to 21 Mar 2017 at 13:00

    A short workshop to have an open discussion on our proposals as part of this consultation. This will take place at the CAA’s London office - CAA House, 45-59 Kingsway, London, WC2B 6TE. If you would like to attend please email


  • Commercial airlines
  • Air Navigation Service Providers
  • Industry representative bodies
  • Eurocontrol
  • Government departments
  • Regulatory bodies


  • Economic regulation