Tall structures can obstruct flying and affect aviation safety when in the vicinity of an aerodrome and penetrate the obstacle limitation surfaces. Also they can be an En-Route obstacle when located between flying destinations .
Examples of Tall Structures
The term tall structure includes tall buildings, television (TV) masts, power plant chimneys, radar antennae, electricity pylons, wind turbines, construction cranes and other.
Figure 1: A tall structure. The Arecibo Telescope Tower, Puerto Rico
An example list of tall structure types with specific examples from around the world is shown in the table below:
|Tall Structure Type||Example Structure Name||Height above ground m/ft||Location|
|TV Mast||KVLY – TV Antenna||629 metres / 2,063 feet||United States (US)|
|Chimneys||GRES-2 Power Station in||420 metres / 1,377 feet||Kazakhstan|
|Radar||Dimona Radar Facility||400 metres / 1,312 feet||Israel|
|Electricity Pylons||Zhoushan Island Overhead Powerline Tie||370 metres / 1,214 feet||China|
|Meteorological Tower||Obninsk Meteorogical Tower||315 metres / 1,034 feet||Russia|
|Wind turbine||Vestas V164-8.0||222 metres / 728 feet||Denmark|
|Telescope||Arecibo Telescope||150 metres / 492 feet||Puerto Rico|
|Building||Burj Khalifa||830 metres / 2,722 feet||United Arab Emirates (UAE)|
Table 1: Example types of tall structures
Tall Structures – TV Transmitters
In the UK there are over 1,150 TV transmitters distributed all over the country. Among which, 67 are main transmitters. Main TV transmitters are usually significantly taller than the rest due to the large areas they serve. Their average height in the UK is 155 metres / 508 feet above ground.
Figure 2: Emley Moor Television Transmitter UK
The 10 tallest TV transmitter structures in the UK are :
|Ranking||TV Transmitter Name||Height above ground m/ft||Location|
|1||Belmont||343 metres / 1,125 feet||Lincolnshire, England|
|2||Caldbeck||320 metres / 1,050 feet||Cumbria, England|
|3||Emley Moor||317 metres / 1,040 feet||West Yorkshire, England|
|4||Durris||314 metres / 1,030 feet||Aberdeenshire, Scotland|
|5||Arfon||311 metres / 1,020 feet||Gwynedd, Wales|
|6||Strabane||309 metres / 1,014 feet||Strabane, Northern Ireland|
|7||Black Hill||308 metres / 1,010 feet||North Lanarkshire, Scotland|
|8||Waltham||301 metres / 988 feet||Leicestershire, England|
|9||Bilsdale||296 metres / 971 feet||North Yorkshire, England|
|10||Mendip||288 metres / 945 feet||Somerset, England|
Table 2: The 10 tallest TV transmitters in the UK
These 10 transmitters can be seen in Figure 1 below.
Figure 3: The 10 tallest TV transmitters in the UK
The tallest TV transmitter structure in the UK is Belmont having a height of 343 metres / 1,125 feet. For comparisons, the tallest TV transmitter in the world appears to be KVLY – TV Antenna in North Dakota, USA having a height of 629 metres / 2,063 feet.
Figure 4: Belmont Television Transmitter UK
Tall Structures – Buildings (Residential, Offices, Hotels)
In the UK there are numerous tall buildings the vast majority of which are located in London and are usually residential, offices and hotels. The 10 tallest buildings in the UK are :
|Ranking||Building Name||Height above ground m/ft||Location|
|1||The Shard||306 metres / 1,004 feet||London, England|
|2||One Canada Square||236 metres / 774 feet||London, England|
|3||110 Bishopgate||230 metres / 755 feet||London, England|
|4||The Leadenhall Building||224 metres / 735 feet||London, England|
|5||25 Canada Square||201 metres / 659 feet||London, England|
|6||8 Canada Square||200 metres / 656 feet||London, England|
|7||Tower 42||183 metres / 600 feet||London, England|
|8||The Tower, One St George Wharf||181 metres / 594 feet||London, England|
|9||30 St Mary Axe||178 metres / 584 feet||London, England|
|10||Beetham Tower||169 metres / 554 feet||Manchester, England|
Table 3: The 10 tallest Buildings in the UK
The tallest building in the UK is the Shard which has an overall height of 306 metres / 1,004 feet. For comparisons, the tallest building in the world is currently Burj Khalifa having a height of 828 metres / 2,717 feet.
Figure 5: The Shard (Left hand side), London, in comparison to other tall buildings and construction cranes
Other UK cities with tall buildings include:
|Building Name||Height above ground m/ft||Location|
|10 Holloway Circus||130 metres / 427 feet||Birmingham, England|
|The Tower at Meridian Quay||107 metres / 351 feet||Swansea, Wales|
|Sky Plaza||103 metres / 338 feet||Leeds, England|
|St Paul’s Tower||101 metres / 331 feet||Sheffield, England|
|109 Bluevale Street||91 metres / 298 feet||Glasgow, Scotland|
|Unity||86 metres / 282 feet||Liverpool, England|
|Obel Tower||85 metres / 279 feet||Belfast, Northern Ireland|
|Windsor House||80 metres / 262 feet||Cardiff, Wales|
|Victoria Hall||77 metres / 253 feet||Wolverhampton, England|
|The Mill and Jerwood Dance House||71 metres / 233 feet||Ipswich, England|
|Martello Court||64 metres / 210 feet||Edinburgh, Scotland|
Table 4: The tallest Buildings in the UK outside London
Aviation Warning Lights
Any tall structure penetrating any obstacle limitation surfaces (vicinity of an aerodrome) or having a height of 150 metres and above (away from an aerodrome) needs be lit . There could be instances where tall structures with heights less than 150 metres will also need to be lit. You can read more about wind turbine aeronautical lighting requirement here.
There are many different types of tall structures that can affect aviation safety. These include TV masts, power plant chimneys, radar antennae, electricity pylons, meteorological towers, wind turbines, telescopes, construction cranes and of course tall buildings (e.g. commercial, offices, hotels).
In the UK there are 67 main TV transmitters with an average height of 155 metres / 508 feet above ground. These are located throughout the UK.
In the UK the vast majority of tall buildings are located in London. Outside London tall buildings exist in urban environments such as Manchester, Birmingham, Leeds, Liverpool, Swansea, Edinburgh, Glasgow, Cardiff, Belfast and other.
Tall structures are likely to keep increasing in numbers. When planning for such developments it is recommended to investigate whether there could be any aviation concerns which could constrain the structure’s height.
 Article 219 of the Air Navigation Order (published within CAP393) states that a tall structure having a height of 150 metres or more above ground level can be an En-route obstacle.
 Ofcom – UK Digital Television Transmitter Details via www.ofcom.org.uk (last accessed 13/07/2015).
 CAP393 – Air Navigation: The Order and Regulations by The Office of the General Counsel, Civil Aviation Authority (last accessed 13/07/2015).