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Aerodrome safeguarding – A balanced approach is required

by BGL Communications on January 4, 2022 Comments Off on Aerodrome safeguarding – A balanced approach is required

Aircraft take-off near Hatton Cross, London Heathrow Airport

With development proposed at or near to many of the UK’s airports and airfields, it is important to establish the possible impacts on aviation safety.

Many airports and airfields are formally safeguarded either as part of their licensing conditions and/or through formal and informal safeguarding maps lodged with relevant local authorities. This process requires local authorities to take account of the safeguarding issues in planning applications for development at or near these airports and airfields. Some 28 of the larger airports in the UK and one in Wales are formally safeguarded under the Town and Country Planning Direction 20021.

A number of other airports and airfields have informally lodged safeguarding maps with local authorities, although this is rather patchy. Where no safeguarding map has been lodged, it is possible that the Local Plan, including any allocation of sites for new housing will not necessarily protect the aerodrome’s interests and safeguarding is ignored in the planning process.

1The Town and Country Planning (Safeguarded aerodromes, technical sites and military explosives storage areas) Direction 2002.

The UK has 123 CAA licenced or certificated aerodromes which are required to meet the relevant obstacle clearance surfaces (OCS) for take-off and approach at the airfield.
As such, all buildings or other obstacles, including temporary obstructions such as cranes must be beneath the relevant approach and take-off OCS for all licensed runways. Whilst there are no legal requirements, the safety implications of building and other obstacles on or close to the approach and take-off paths at non-licensed aerodromes need to be taken into account in planning consents, based on aircraft performance, pilot experience and other safety criteria.

In addition to the OCS, new buildings and other obstacles at or close to an airport or airfield can impact on the performance of navigational aids and radar installations. As such. the possible impact on aviation needs to be assessed. This particularly applies in the case of new wind turbines which can create clutter on both primary and secondary radar screens. Solar installations can also deflect radar signals and create glare for pilots.

Further safeguarding criteria that need to be assessed include the risk of bird strikes, particularly if the proposed development includes or increases the size of areas of water or waste disposal. Many safeguarding maps require local authorities to consider any possible increased risk of bird strikes up to 10-15 miles from the airport or airfield.

The UK’s busier airports with over 18,000 air transport movements (ATMs) per annum are all required to have Public Safety Zones (PSZ) at the ends of each runway where development is restricted within these zones to minimise the risk of death or injury in the event of an aircraft accident on take-off or landing. The PSZs are elongated isosceles triangles and are based on the calculated risk of an aircraft accident causing death or injury to those on the ground. Whilst there is a general presumption of no development within PSZs, there are certain exceptions, including the use of risk appraisal and cost-benefit analysis to justify some development in particular circumstances.

Farnborough Airport – Public Safety Zones

It should be noted that, whilst the safeguarding criteria described above should be applied, there are no other statutory safeguarding requirements for other planned development close to the airport or airfield. It is possible however that some development may occur underneath or close to flight paths but not necessarily infringe the airport or airfield’s obstacle clearance surface. An issue here is that this development might potentially impact on aviation safety if it restricts the availability of a suitable forced landing area for aircraft in the event of an engine failure or other emergency. In this context, it should be noted that, whilst there is no statutory requirement for safeguarding in these cases, it is generally regarded as good practice for such issues to be taken into account in planning decisions. In practice, the pilot has full responsibility for flight safety outside the airport or airfield boundary, although it is possible that an airfield may object to a nearby development if it believes that pilots would be unwilling to use the airfield in these circumstances.

Following a Public Inquiry for a new Motorway Services Area (MSA) near Denham Aerodrome in Buckinghamshire held earlier this year2, the Inspector ruled that, whilst the loss of land at the MSA would technically increase the safety aviation risk in the event of a forced landing, this would not be of such magnitude to prevent pilots from flying from Denham Aerodrome.

Similar considerations apply in the case of the planned development of 3,000 new homes at Chalgrove Airfield in Oxfordshire which would co-exist with aviation operations by the existing leaseholder, the ejector seat manufacturer, Martin-Baker. Whilst the developer, Homes England, believed that the development would not compromise aviation safety, this was challenged by Martin-Baker and the CAA’s Aviation Advisory Team who argued that combined housing and aviation use at the site would not be possible. Homes England has now withdrawn its planning application but intends to submit alternative proposals in the future.

2Appeal Ref: APP/X0415/W/21/3272171. Land between Junctions 16 and 17 of the M25, near Chalfont St Peter.

Ultimately a balanced approach is needed where planning consent for development near airport and airfields may potentially infringe on aviation safety. In most instances, such planning consent will not be granted where a development breaches statutory safeguarding requirements such as the OCS. In other cases, detailed risk assessments need to be carried out based on the likelihood and potential severity of any aircraft accident or other incident. It should be noted that the acceptability of the aviation safety risk may depend on the types of aircraft flown. It might be reasonable to expect that pilots of single engine piston aircraft would accept a higher safety risk than say, pilots of commercial aircraft responsible for their passengers carried.

As specialist aviation consultants, Alan Stratford and Associates has undertaken a wide variety of airport and airfield safeguarding studies for developers, local authorities and community groups. In our experience, many safeguarding issues can be overcome with appropriate modifications to plans or through some adaptation of airport or airfield operations eg changes to flight paths or circuits.

Given the scarcity of suitable sites in the UK, it is inevitable that plans for development near airports and airfield will continue to be put forward. Whilst each case is different, it is often possible for this to co-exist with aviation operations with no significant increase in the safety risks, provided there is mutual understanding and compromise on either side.

BGL CommunicationsAerodrome safeguarding – A balanced approach is required

The future of the UK’s GA airfields

by BGL Communications on October 22, 2018 Comments Off on The future of the UK’s GA airfields

Balancing the needs of aviation and the housing sectors


The UK’s general aviation sector provides some £3.0 bn GVA (Gross Added Value) to the economy – but with increasing pressure on local authorities to find suitable sites to meet the Government’s housing targets, many smaller general aviation are under threat of closure.  Currently, all airfields are regarded as brownfield sites, which have priority status for development, although the existing policy in the National Planning Policy Framework (NPPF) is currently under review by the Ministry of Housing, Communities and Local Government in conjunction with the Department for Transport.

Most general aviation airfield can break even through a range of aeronautical and non-aeronautical revenue streams, although funding for new infrastructure is often prohibitive.  With its land value as housing considerably in excess of that as an ongoing airfield, it is not surprising the many privately-owned airfields are under threat.    General aviation has at best been static in the UK over the past 10 years, although there are some growth areas including flight experience flights, microlights and home-built aircraft.  Larger airfields with the appropriate facilities attract the more profitable corporate aircraft, dependent on their location in relation to major conurbations.   There is however considerable competition to attract corporate aviation, although peak time slots at many larger airports are scarce and expensive.   As such, many smaller airfields must rely on flight training and privately-owned based aircraft to survive, coupled with any additional revenue from hangarage, the cafe and from any small businesses based on the site.   In addition, many small airfields support the local community through a variety of activities ranging from Sunday markets through to acting as a base for the helicopter emergency services (HEMS).

Redhill Airport in Surrey faces an uncertain future

At least ten UK airfields have either recently closed or are under imminent danger.  These include Andrewsfield, Fairoaks, Long Marston, Manston, Netherthorpe, Plymouth, Redhill, Panshangar and Wellesbourne.    Manston Airport closed in 2011, when it was purchased by Lothian Shelf 718, a property company with plans for a mixed use development including 2,500 new homes.  This, however, is being contested by RiverOak Strategic Partners, who have applied for a Development Consent Order (DCO) to compulsory purchase and reopen Manston as a major freight airport with some passenger services and GA use.   Plymouth Airport has been mothballed since 2012 but it is protected under the Local Plan.  The current owners, Sutton Harbour Holdings have prepared a masterplan for mixed use development, although this is challenged by a community group, FlyPlymouth, seeking to reopen the airport.  Fairoaks Airfield in Surrey faces redevelopment as a Garden Village with some 1,000 new ‘eco-friendly’ houses.

Redhill Airport is not under immediate threat, but is safeguarded under the local council’s Development Management Plan for new housing after 2027.   Panshangar Airfield near Welwyn closed in 2014 following the expiry of its lease and the owner has submitted a Planning Application for some 650 homes. Two rival groups however have prepared proposals to relocate the grass runway and clubhouse so that aviation can be retained on the site.   Wellesbourne Airfield is the subject of a dispute between the owners, who wish to develop the site, the local planning authority, Stratford District Council and the airfield, which is one of the busiest GA airfields in the UK.  A number of on-site businesses have not had their leases renewed and will be forced to leave the airfield.  Whilst this has been upheld through a court hearing, the business tenants have recently been granted leave to appeal against this decision.

Fairoaks Airport – Proposals for a 1,000 home Garden Village

It is clear that some airfields under threat of closure may be fighting a losing battle.   Nevertheless, the economic and social benefits from general aviation demand that some protective status is required.

The All Party Parliamentary Committee for General Aviation, chaired by the former Conservative minister, Grant Shapps, himself a private pilot, has been particularly active in lobbying Government to prevent any further decline in the sector.

The new guru for GA appointed by the Department for Transport, Byron Davies, has commissioned a study to examine whether a network of commercially-viable GA airfields should have protected status under the NPPF, although there would doubtless be some debate as to which airfields are included in the list.

Balancing the economic and social benefits of general aviation with commercial and housing priorities is a key challenge for both the sector and for government. By adopting a pro-active approach to the extent and nature of the airfield infrastructure required, it is possible to protect the interests of all stakeholders.

BGL CommunicationsThe future of the UK’s GA airfields

Safeguarding and Public Safety Zones at UK airports. Are current procedures fit for purpose?

by BGL Communications on October 21, 2018 Comments Off on Safeguarding and Public Safety Zones at UK airports. Are current procedures fit for purpose?

To protect their future operations, UK airports and airfields need to ensure that any proposed buildings or other nearby development, such as wind turbines, do not infringe on the safety of their operations.

Similarly Public Safety Zones are designed to ensure that those living or working near airports are exposed to an acceptable level of safety risk of an aircraft accident. But are the current procedures meeting these objectives and are they being adhered to by all stakeholders ?

UK legislation provides for a number of measures to safeguard airports and airfields, either on an official or unofficial basis. But despite this, many local authorities and some airfields are not fully aware of or disregard Government guidance in this area, which potentially threaten the safety of aviation operations when such developments are proposed within the UK planning system.

There are two types of aerodrome safeguarding – official safeguarding, which applies to some 28 of the UK’s 82 airports and airfields holding a CAA or EASA licence and unofficial safeguarding, which is based on an agreed safeguarding procedures between the aerodrome licence holder and the relevant local planning authority. In both cases, aerodromes should submit a safeguarding map to the local planning authority showing the protected areas around the airport which need to be free of such development including the obstacle clearance surfaces and other protected areas to ensure the integrity of navigational aids and communications equipment. Further constraints apply in relation to the maximum heights of other proposed buildings or wind turbines close to the aerodrome.

If a proposed development breaches these protected areas, the aerodrome licence holder must be contacted by the local authority and should be a consulted under the planning process. In the case of those aerodromes covered under official safeguarding, the safeguarding map must be certified by the CAA. Furthermore, the Government advises that these maps and the safeguarding policy are shown in the local development framework and other strategic planning documents. If the local authority is minded to grant planning consent to a development to which an officially safeguarded aerodrome has objected, the CAA must be consulted. In the case of unofficial safeguarding, there is no direct involvement of the CAA, although the Government recommends that the CAA is consulted about any proposed development with a height in excess of 90m in the vicinity of the airport or airfield.

The obstacle clearance surfaces around CAA and EASA licensed aerodromes are defined within CAP 168 ‘Licensing of Aerodromes’ or within the relevant EASA certification specifications, which are based on those in ICAO Annex 14. Guidance for the obstacle clearance requirements at unlicensed airports and airfields is given in CAP 793 ‘Safe Operating Practices at Unlicensed Aerodromes’. In such cases, the safeguarding requirements are less stringent although some unlicensed aerodromes adopt the criteria in CAP 168 or its EASA equivalent. In addition to the constraints on building development, the safeguarding policy agreed with local planning authority can require mandatory consultation on other proposed activities near the airfield including the siting of cranes, shooting, kite flying etc. Any planning application which might lead to increased bird activity near the airport should also be referred to the licence holder, including those involving rubbish tips, lakes and landscaping.

The typical format for an airport safeguarding map is shown in the example below:

Belfast City Airport – Safeguarding Map

In addition to the safeguarding criteria, those UK airports with more than 1,500 air transport movements (ATMs) per month should establish Public Safety Zones (PSZs) at all runway ends. This Public Safety Zones should be prepared by the airport operator based on the statistical risk of an individual living or working within the area dying as a result of an aircraft accident. Under current Department for Transport (DfT) legislation, PSZs for 1 in 100,000 and 1 in 10,000 annual risk contours should be prepared every seven years and lodged with the local planning authority. Except in certain specific cases, there should be a presumption of no new or replacement residential development within the 1 in 100,000 annual risk contour although certain types of commercial development such as warehousing, with relatively few employees on site are deemed to be acceptable, The 1 in 10,000 annual risk contour should be free of all residential and commercial property and, if this is not the case, the airport operator is expected to make a compulsory purchase order to acquire and demolish these properties. There are some exceptions to this requirement, including land used for long-stay car parking, buildings housing machinery etc without any associated permanent employees and golf course (but not clubhouses). The precise definition of a PSZ requires detailed modelling based on the expected movement levels and accident data for the types of aircraft flown. A typical example, showing the 1 in 10,000 contour (in blue) and the 1 in 100,000 contour (in red) is shown below:

Farnborough Airport – Public Safety Zones

PSZs are in place at many of the busier airports in the US and continental Europe – although other countries adopt different approaches in terms of their design and their size based on their own definitions of the acceptable level of risk. The UK model was developed by NATS in the 1990s and is based on straight in and straight out approach and take-off paths. Other models, such as that developed by the Netherlands Aerospace Centre (NLR) take account of curved approaches and turns on take-off. Significant forecasted traffic growth at an airport, such as that projected at London City Airport in its masterplan for 2020-2035 or at the proposed new cargo airport at Manston in Kent can result in a substantial increase in the size of the PSZ, with major impacts for local residents and businesses.

A study by Nathaniel Lichfield and Partners suggests that whilst all the UK’s 82 licenced aerodromes should adopt safeguarding measures, only 19 of the 28 local authorities responsible for officially safeguarded airports have incorporated these safeguarding policies in their local plans. A further 13 local authorities have adopted voluntary safeguarding policies in their local plans. This indicates that over a half (42) of the UK’s licenced airports have no local plan safeguarding in place. A recent case involving the planning decision to build a new IKEA store and 600 homes near Brighton City (Shoreham) Airport had little technical input on the aerodrome safeguarding issues.

The Government acknowledges that there are still a number of shortcomings in the aerodrome safeguarding procedures as indicated in the Department for Transport’s Aviation Strategy consultation report published in December last year, although it does not recommend mandatory official safeguarding . In the case of Public Safety Zones. Eurocontrol recently carried out a study to assess how its environmental risk model, IMPACT, could be extended to define airport PSZs on a pan-European basis. Whilst the shortcomings are now recognised, it remains to be seen as to how these procedures might be improved in the interests of all stakeholders.

Alan Stratford and Associates provide a range of services relating to aerodrome safeguarding.


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BGL CommunicationsSafeguarding and Public Safety Zones at UK airports. Are current procedures fit for purpose?