Pre-planning assessment

Wind farm pre-planning - forewarned is forearmed


We offer a range of pre-planning services, which mirror those carried out when you submit a full planning application.

They will help you determine at an early stage whether there is likely to be an aviation objection to your wind farm.

This can save you a considerable sum of money and provide a clear way forward.

Who might object?

There are normally two civil aviation consultees who may object to your planning application:

  1. NATS En-route. We are a statutory consultee and are responsible for ensuring that all of our assets are protected from interference.
  2. Airport authorities. Also statutory consultees, they are responsible for safeguarding their airport operations and associated assets. At many UK airports NATS provides air traffic control services and also some safeguarding services. It is often the ATC provider who delivers technical and operational advice on wind farm applications, in which case they advise the airport authority on whether to object or not. However, the airport authority will make the ultimate decision.

What is required?

Depending on the location of your intended development, you will often need the consent of both NATS En-route and the relevant airport authority in order to proceed through planning. They will make their decision after carrying out the relevant assessments as shown in this table.

Consultee Assessments that may be required
Airport Airport Technical Airport Operational OLS IFP/ATCSMAC
NATS En-route En-route Technical En-route Operational    

Type of assessment

1 Technical

This looks at radar line of sight to determine whether or not your development would be likely to produce returns on any radars. It also assesses the potential impact on communications and navigation equipment.

2  Operational

This takes the results of the technical assessment and passes them to the operational units that use the assets. The unit assessors decide if the proposal might have an impact on the specific operational criteria in place at that unit.

3  OLS (Obstacle Limitation Surface) assessment

This looks at the physical safeguarding of an airport and the protection of various surfaces. In general, the OLS assesses surfaces up to 15km from a runway. It is designed to ensure that obstacles do not prevent normal airport operations. (More information on this can be found in CAA publications CAP 738 and CAP 168.)

4  IFP/ATCSMAC (Instrument Flight Procedures and ATC Surveillance Minimum Altitude Chart)

This assessment checks the effect that obstacles might have on the Instrument Flight Procedures and the minimum levels that can be allocated under radar control at the airport.  If there is an impact on these procedures it can have a significant effect on operations.

How can we help?

We can run through all the assessments shown above at the pre-planning stage. This will give you a detailed view of the likely outcome of any full application – saving you considerable sums of money and informing your planning and decision-making. It will also give you the confidence to proceed in the knowledge that:

  • You will not receive any civil aviation objections
  • Or, if you do and where available, we will present options for a clear path to acceptable mitigation. (If not and where appropriate, under a separate contract we can create an impact and options paper)

Note that for airport assessments, the airport authority will ultimately decide on whether to lodge an objection. NATS only provides them with technical and operational advice (TOPA). The TOPA report will give you NATS’ position at that time, but any recommendations are not guaranteed to result in a no-objection when the proposal is submitted to planning.

Pre-planning packages

We offer the following three pre-planning packages. Each report includes a statement of the likely NATS advice to the airport authority, in terms of objection or no objection, should the proposal proceed to planning at that time.

  1. Airport Technical and Operational Assessment (TOPA). This includes technical and operational assessments in relation to airport assets. The report details the likely impact and the operational response of the relevant ATC unit.
  2. En-route Technical and Operational Assessment (TOPA). This includes technical and operational assessments in relation to en-route assets. The report details the likely impact and the operational response of the relevant ATC centre.
  3. Combined Airport and En-route Technical and Operational Assessment (TOPA). This includes both an airport and en-route TOPA.

We can also provide you with OLS and IFP/ATCSMAC assessments.

Where can we provide pre-planning services?

The contents and availability of assessments at certain airports differs according to the airport safeguarding processes.

  1. We can provide you with the en-route TOPA for any location in the UK.
  2. We can provide you with the airport TOPA for these airports:
    • Aberdeen
    • Cardiff
    • London Heathrow
    • London Stansted
    • Manchester

    You may also need OLS and IFP/ATCSMAC assessments as well as the TOPA assessment. If this is the case, please contact us to discuss the situation.

  3. We also provide the airport TOPA for Southampton & Glasgow. However you need to contact the airports directly in the first instance for initial safeguarding advice. You will then be advised to contact NATS to carry out the TOPA assessment.

How much will it cost?

  1. Airport TOPA                                     £1,250 plus VAT
  2. En-route TOPA                                   £1,250 plus VAT
  3. Combined TOPA                                £2,150 plus VAT

You can submit an application and pay online with a credit card.

Contact us

Please contact us on 01489 444321 or via the form below if you would like more information:

  • By completing this form, you are consenting to NATS holding your personal information. For further details on how NATS manages your personal information please see our privacy notice.

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