The London Heliport takes any environmental issues, such as noise pollution, very seriously and operates a “Fly Neighbourly” policy. ‘The following pages contain information on helicopter operations over London and at the London Heliport. The intention is to inform those who would like to know more about such operations and it is hoped that the answers will be found here. Should you have any concerns please go to the links at the end of these pages.
The London Control Zones
The London Heliport strives to ensure that any environmental impact on its local area is kept to a minimum. In order to achieve this all helicopter operators require a thorough briefing on the “do’s and don’ts” when using the Heliport and their behaviour is closely monitored. However, the airspace surrounding the Heliport and over London generally does not belong to the Heliport but to the London Control Zone (known as the London CTR) in the west and, to the east, London/City Control Zone (known as the London/City CTR). The primary controlling authorities are Heathrow Radar and Thames Radar respectively. A chart showing the two Control Zones can be downloaded here. You will see that The London Heliport is located at the east end of the London Control Zone.
Helicopter Routes within the Zones
Within the Zones are helicopter routes designated H3, H4, H5, H7, H9 and H10. These routes were established many years ago with a primary reason to keep single engine helicopters over open ground or the River Thames and away from Heathrow Airport traffic. With the advent of twin engine helicopters, traffic that doesn’t conflict with Heathrow Airport is allowed to fly off a designated helicopter route but under the positive control of one of the air traffic services that provides radar and at a height of not less than 1000 feet above the ground or less if they have a specific permission to do so from the Civil Aviation Authority (CAA).Police and Helicopter Emergency Medical Service (HEMS) helicopters have this permission. On the designated helicopter routes the standard lowest permitted height is 500 feet above the ground, except when landing or taking off in accordance with normal aviation practice.It may be of interest to know that some single engine helicopters are permitted to fly off the prescribed helicopter routes providing they satisfy the rules and regulations and, again, hold a specific permission from the CAA.
The London Heliport Air Traffic Zone
The London Heliport has airspace assigned to it which covers the area of a circle with a diameter of 2 nautical miles with the heliport being the centre of that circle, called an Air Traffic Zone (ATZ). The vertical airspace varies but the area to the west (up stream) of the lines designated as being “10 to 6”, if using a conventional clock face, has a maximum height of 1000 feet and the area to the east of the clock’s hands (down stream), a maximum height of 1500 feet. These maxima are imposed by the required vertical separation distance (for enhanced safety) between helicopters landing at or passing by the heliport and aircraft landing at Heathrow.
Helicopters are legally permitted to fly anywhere within this ATZ and, if making an approach to or taking off from the heliport, they could be below 500 feet although in reality this is most unlikely – except when over the river or, perhaps, if a police or HEMS helicopter. Whenever possible helicopters operating to or from the heliport will fly over the centre of the river and be at the highest possible safe altitude whilst making an approach or departure. However, there may be circumstances when safety considerations over-ride all others and the helicopter will be told to fly off river in order to provide adequate separation from another helicopter. This means that both helicopters may fly over populated areas but they will be at a safe height and they will pass over as quickly as possible.
Wind, temperature, air density and the helicopter’s weight and speed influences the helicopter’s take off, landing profiles and resulting noise. If there is a nose wind, less power is required to keep the helicopter airborne and therefore a steeper approach/departure angle can be achieved. Occasionally, when air density and temperature are at a particular level, noise from a helicopter’s main rotor can be perceived as being impulsive in nature; this phenomenon is known as “blade slap”. Blade slap may also occur when the helicopter slows down to descend or turn and this will cause an increase in perceived noise. It is sometimes possible to reduce the speed and/or the turn and descent angle to reduce blade slap but it is not always achievable – however the pilot will try. The Heliport is only allowed to operate from 0700-2300 hrs, 7 days a week. If you experience noise outside of these times, it is usually an Emergency Service aircraft. For further information on twitter see #mpsinthesky or contact your local police station.