General Helipad Information
International Standards and Recommended Practices
The International Civil Aviation Organisation (ICAO) is the body which is
responsible for compiling and disseminating information concerning standards and
recommended practices. Contracting States are required to notify the Organisation of any differences between their national regulations and practices and those laid down in ICAO documents. The United Kingdom is one of the Contracting States and has notified no differences to the internationally recommended standards and practices for heliports, helipads or helidecks, either at ground level or elevated. These are described in detail in ICAO Annex 14 Volume II Heliports and in the ICAO Heliport Manual.
However, it should be borne in mind that these ICAO standards and recommended practices are presently the subject of a major review by Contracting States and industry bodies. UK CAA and industry anticipates that the standards and recommended practices for ground level and elevated heliports are likely to evolve significantly to take full account of the operational flexibility afforded to Rotary Wing aircraft.
The above documents are intended to provide detailed guidance for the location,
construction, marking and lighting of heliports etc. In the UK helicopters are required to operate from licensed sites only if they are conducting scheduled services or if they are being used for ab initio pilot training. All other flights, apart from training flights, do not attract the legal requirement to operate from licensed heliports.
For certain helicopter ‘special events’ which attract large numbers of movements, (a
take-off or a landing is one movement) estimated at over 100 per day, it is recommended that consideration is given to applying to the CAA (Aerodrome Standards Department) for a temporary aerodrome license. This ensures that safety arrangements at the site are appropriate to the anticipated level of activity. Other sites used in conjunction with special events at which a lower number of movements are anticipated, even when not requiring a licence, should nevertheless be notified to the CAA and may be inspected on the day of the event by Flight Operations Inspectors. Whether licensed or not, sites should only be selected which take full account of the performance requirements of all helicopter types likely to operate the site.
Helicopters are, by design, able to use non-conventional operating sites. Helicopters only offer any truly significant advantage over the use of aeroplanes for passenger transport by being able to operate away from conventional aerodromes into and from ad hoc sites or specially designed heliports.
If it is necessary, or if it is desired, to license a heliport, application should be made to the CAA Head of Aerodrome Standards Department. An Aerodrome Inspector will be assigned who will provide detailed guidance until the site is licensed, after which the site will be periodically audited and the inspector will act as the liaison link between the aerodrome licensee and the CAA. A fee is payable.
Unlicensed Sites (Ground Level)
When considering an ad hoc site for use by single engine (Group B/Class 3)
helicopters it is necessary for public transport flights, and recommended for others, to allow sufficient space for the use of the take-off and landing profiles certificated and described in the aircraft’s Flight Manual. The take-off profile is similar for all single engine types. From a low hover the aircraft is accelerated close to the ground until the safe climb speed (about 40/50 kts) is reached, at which stage the aircraft is climbed away maintaining this speed. The take-off distance is scheduled in the performance section of the flight manual from the hover to 100 feet above the take-off point assuming nil wind accountability. The distance varies with aircraft type. Examples of these distances are shown at Appendix 3. The first one third of the take-off distance should be at least 30 meters wide and the surface must be relatively firm and flat and free from all obstacles. The remaining two thirds of the Take-off Distance Available (TODAH), may contain insignificant or frangible obstacles within it, such that the aircraft, in the event of failure of the power unit, can force land without hazard to the occupants of the helicopter and without endangering persons or property on the surface. It is assumed that in the event of a power unit failure occurring from the time the aircraft moves away from the
hover until it reaches 100 feet, that the ensuing forced landing will be made without any significant changes in aircraft direction being attempted. Above 100 feet the pilot is able to maneuver progressively more easily with increasing height above the surface to select a suitable, clear space, for a forced landing. Landings and take-offs by single-engine helicopters are not permitted at sites within congested areas unless it can be shown that there is no risk to third parties and that there are sufficient open spaces in which to force land, if necessary.
Multi engine helicopters can be operated in all Performance Classes (Class 1/Group A, Class 2/Group A Restricted and Class 3/Group B). Helicopters with more than 19 passengers (or when operating in a Congested Hostile Environment) must operate in Performance Class 1 – with full engine failure accountability in all stages of flight.
Helicopters with 19 or less but more than 9 passengers must operate in Performance Class 1 or Performance Class 2 – with engine failure accountability in all but the initial take-off and final landing segments. Helicopters with 9 or less passengers may operate in Performance Class 1, Performance Class 2 or Performance Class 3. For flight in Performance Class 3, and the initial take-off and final landing segments of Performance Class 2, the helicopter must be able to perform a safe forced landing at all stages of flight.
For those sites which are in congested areas and which require Rule 5 permissions
from the CAA, unless the operator can show that there is no third party risk in the event of a power unit failure, such permissions will be conditional upon the aircraft being operated to Group A/Class 1 performance. Thus in the overwhelming majority of such cases Group A/Class 1 performance is the required norm.
A Group A/Class 1 site must be large enough to accommodate the most demanding
helicopter type intending to use the site with due regards to specific performance
techniques and limitations set out in the helicopter’s flight manual, but in any event must be large enough to accommodate twice the overall length of the largest helicopter intending to use the site. The ground should be firm and substantially level and free from loose articles which could endanger the aircraft or property or persons in the immediate vicinity of the helicopter downwash effect. Helicopter downwash is proportional to the weight and size of the machine producing it. For example an S61N displaces a volume of downwash equivalent to its weight of over 9 tonnes. The effect on nearby structures and people can be considerable. Loose dirt or gravel can cause damage to vehicles parked too close, whilst vulnerable persons can be blown over by the rotor downwash or hurt by
flying debris. The area downwind of the helicopter is worst affected. In any case it is recommended that, whilst the helicopter is maneuvering in a low hover, no object should be permitted closer than 1.5 x Rotor Diameter or 30 meters from the centre line of the helicopter, whichever is the greater.
The helicopter, especially in a congested area, can be noisy and can be the cause of
complaints from members of the public. Noise certificates for helicopters are only
applicable to types newly certificated after 1 August 1986. In effect therefore many
helicopters on the UK civil register are currently not subject to noise restrictions.
Unlicensed Sites (Elevated, Onshore)
Roof top helipads, by their very nature, are normally situated in congested areas. The operator therefore will require a Rule 5 permission from the CAA. By virtue of the nature of such sites and the perceived risk to third parties in a building itself or close by, only those helicopters capable of Group A/Class 1 performance are permitted to land at, or take-off from roof top sites. The helicopter type intended to be used must possess a helipad profile for the specific rooftop site within its flight manual; this technique, in the event of a failure to one of the power units occurring at any time during the take-off or landing, will enable the aircraft to reject safely on to the helipad available or to fly away avoiding all obstacles by a vertical margin of at least 35 feet. In the absence of such a profile, permissions will only be granted provided the helicopter is able to hover outside ground effect with one engine inoperative at the site and in the prevailing ambient conditions.
The minimum size of the helipad will also be described in the Flight Manual or Flight Manual Supplement for the aircraft type under consideration. Roof top helipads not conforming to these dimensions should not be considered. Proposed use at night will attract the need for a CAA proving flight. Factors considered will include helipad size, obstacle environment, helipad and obstacle lighting provided, including use of approach path indicators (where provided) and visibility from the helicopter to be used. Thus a flight test programme, undertaken by the operator in conjunction with the CAA, will normally be required and a flight manual supplement and/or operations manual supplement issued for the particular site as an end product of the test
The provision of Rescue and Fire fighting services at elevated sites when used for any category of flights should be provided to the scales laid down. Close liaison with local Fire Brigade and HSE agencies during the planning and construction stages of the roof top site should be established and maintained thereafter to ensure a viable “disaster” plan is in place when the roof top becomes operational.
In all cases it is recommended that the owner of a roof top facility proposed for use asa helipad should consult with the helicopter operator(s) and the local planning authority before committal to the project. Recent experience has shown that where planning permission goes to public enquiry, environmental considerations weigh heavily in the decision making process. The general public is aware of environmental matters and due recognition should be given to these sensitivities.
Roof top heliports should be recorded with the CAA. To this end an architect’s
drawing/plan together with aerial photographs of the site and/if, the roof top facility already exists, photographs taken to cover the area all around the site, should be forwarded to Flight Operations Inspectorate (Helicopters) in the case of public transport flights and to the General Aviation Department for private operations.
The structural and load bearing characteristics should be sufficient to accommodate the dynamic loading requirements caused by a helicopter having to force land on the site.
Local Authority Planning Consent
In general an ad hoc helicopter site will not attract the need for planning consent
unless it is intended for use on more than 28 days in any calendar year. However, if any permanent structure is erected in connection with its use as a helicopter site, such as a hangar or hard standing, or if individual local council policies so demand, it may be necessary to obtain planning consent. It is always advisable to talk with the Local Planning Authority if there is any doubt as to the effect of such a site on the local community. For those sites intended for irregular, periodic use and for sites in congested areas it is also necessary that the local police are informed of any intended flying activity.
Recommended Helipad Sizes, Markings and Lighting (Onshore)
The information presented in the figures in the attached appendices and tables has
been extracted from various sources found to be of interest to prospective site keepers. Leading particulars of many helicopter types are also included together with “worked examples” of Group A/Class 1 minimum sized ground level sites.
Sites Close to Existing Aerodromes
Where helicopter landing sites are established close to operating aerodromes,
especially within an Aerodrome Traffic Zone (ATZ), or otherwise within a radius of 2 nautical miles from any aerodrome, details of the site must be given to that aerodrome management or Air Traffic Service (ATS). The aerodrome management and/or ATS will need to mark the location of the site on their charts and maps in order to provide adequate local briefing and safe and speedy reaction to dealing with radio calls from helicopter pilots using the site. Pilots operating to these sites must comply with the aerodrome procedures when operating within the ATZ.
The site keeper has the duty of care to ensure that the helicopter landing site
information is lodged with the aerodrome(s) concerned. The information can consist simply of the name of the site; the grid reference; and a contact telephone number.
Rescue and Fire Fighting Services (RFFS)
For licensed heliports, both temporary and permanent, Aerodrome Standards
Department will impose an RFFS requirement as part of the license. A heliport is not permitted to operate as a licensed facility whenever these requirements cannot be met.
However, site keepers are reminded that the responsibility for the safety of
all helicopter flying operations, at unlicensed sites, including adequate provision of
RFFS, lies wholly with the helicopter operator.
Recommended Helipad Sizes, Markings and Lighting for Onshore Helicopter Sites
Final Approach and Take Off Area (FATO)
This is the term applied to the area over which a helicopter will execute the final partof the final approach and the initial part of the take off. It is analogous to an aero plane runway and must be suitable for the type of helicopter under consideration to reject on to in the event of a power unit failure. Unless the extent of the FATO is clearly self evident, for permanent installations, the area should be delineated with white markers 1 meter wide as follows:
For a square or rectangular FATO the marker length should be 1 x 3 meters with at
least 3 per side including a marker at each corner and a maximum spacing between
markers of 90 meters; FATO markings should be visible from 1000 ft/ 2km.
For a circular or any other shaped FATO, the markers should be equally disposed
around the perimeter with a maximum spacing of 10 meters between markers and a
minimum of 5 markers.
FATOs for temporary, short term use sites may alternatively be delineated with high visibility tape or similar markers provided the extent of the FATO is clearly
distinguishable and temporary markings are not likely to be blown around and become a hazard to the helicopter or bystanders.
The FATO should be surrounded by a Safety Area (SA) 3 meters or 0.25 times the
greatest dimension of the helicopter width, whichever is the greater. Markers should designate the FATO plus Safety Area(SA) together NB: the SA need not necessarily be a load-bearing surface.
The FATO plus SA should be as level as possible. It is recommended that the overall slope of the FATO should not exceed 3% i.e. 1 degree 43 mts.
Touch Down and Lift Off Area (TLOF)
A load bearing area of any shape on which it is intended that the helicopter shall land on from, and take off to, the hover. It may form an integral part of the FATO or be situated apart from the FATO depending on the disposition of the site. It’s diameter should be at least 1.5 times the largest dimension of the undercarriage of the largest helicopter intended to use the site and should take account of the distance by which any of the aircraft doors extend beyond the dimensions of the undercarriage.
The touchdown marking should be yellow circle 0.5 meters wide. The inner diameter of the circle should ideally be 0.5 times the greatest dimension of the largest helicopter intended to use the site but may have to be predicated on the dimensions given at paragraph above. For all but hospital sites a white “H” 3 metres by 1.8 metres with a line width of 0.4 meters should be provided to indicate the aiming point for the helicopter pilot to land on. Hospital sites should be provided with a red “H” superimposed on a white cross. Where the TLOF is set apart from the FATO, it may be necessary for a pilot to make an approach to a particular point on the FATO before proceeding to the TLOF. In this case a white triangular Aiming Point Marker, as described in ICAO Annex 14, Volume II, Section 5.2.6 may be used.
Paragraph 1, sub paragraph 1.6 explains the legal responsibilities for the provision of lighting for the public transport of passengers at night.
It is unusual for private helipads (other than hospitals) to have a requirement for
Lighting. The latest “best practice requirements” for FATO and TLOF
lighting systems are described in the relevant sections of Annex 14 volume 2, No 3
Wind Direction Indicators
A wind direction indicator may be a wind sleeve, flag or continuous smoke source. It should be situated so as to be visible from a helicopter in flight, in a hover or on the movement area and should indicate the wind conditions over the FATO in such a way as to be free from the effects of airflow disturbances caused by nearby objects or rotor downwash. It should be illuminated for night use.