UK Landouts Database and CGC Field Book

This page was last updated on 11 February, 2021.

Control Points for UK Airfields

Various sources
These files give the location and details of landable fields in the UK so that your navigation system can show them in addition to the BGA turnpoints. If it is necessary to abandon your task and land out, these fields can be used as an alternative to landing in long crop, especially in midsummer.
The landout fields have been verified using Google Earth and the UKGA website to check lat & lon, identify runways, frequencies and hazard warnings. The airfields may not be suitable for all gliders: it is the pilot's responsibility to determine whether an airfield is suitable for landing his glider given his skill level and experience.
Farmers strips get ploughed over, and even concrete runways get dug up. There is no warranty as to the currency of these landable fields. You could arrive low to something marked as a field in this file, and find that there is no safe landing.
Always consult the relevant publications for current and correct information. This service is provided free of charge with no warrantees, expressed or implied.
User assumes all risk of use.

David Taylor, Martin Gregorie April 2016



The UK Landouts Database is an attempt by David Taylor and Martin Gregorie to provide information about glider landout fields in the UK in a form that can be loaded into navigation instruments for reference during a flight and where it can be automatically overlaid onto a moving map display.

Cambridge Gliding Club maintains the CGC Field Book which provides a subset of the information in the UK landouts database. It is organised and maintained the same way as the main database, though its update frequency is different. You can either download and use the UK landouts database or the CGC Field Book but there is no point in using both.

The current release supports current versions of:

The long term intention is to extend support to other navigation instruments as and when this is asked for and we are supplied with the file formats these instruments use. When this happens we will change the distribution method to make it rather more like TPSelect: the conversion tool will be made available along with the master file so pilots can generate the files their navigation instruments require. In the mean time we are publishing end-user files as described below.

How the database is organised

The database is maintained as a set of master files, each containing data from a separate source. There is one entry for each landout field which contains everything we know about that particular field. The master files use the OpenField format, which has been specified to hold data about landout fields in a format that is independent of the navigation devices used to display it during flight. Device-specific files are created by running the master files through a Java program, OpenField, that generates files for a nominated navigation device. The generated data falls into three types of file:

BGA Turnpoints list This file is input to OpenField to allow the program to determine whether a landout is a recognised BGA turnpoint or not. It does not generally include airfields, so the only landouts in it are turnpoints that happen to be on or very near to airfields. This means that almost all of them are associated with gliding club fields. You can use either the Winpilot (CAI) or SeeYou (CUP) file format with LK8000 and XCSoar. However, you must use the correct descriptions file for the turnpoint format you've chosen because CUP and DAT files use different name formats. The descriptions file has to use the same name format as the turnpoint and landout locations files for the description to be found and displayed by your navigation device.
Landout locations This file contains GPS co-ordinates for airfields and other suitable landout fields that are not included in the BGA Turnpoints list. It must be in the same format as your BGA turnpoints file.
Landout descriptions

This file contains a free format description for each of the known landout fields that appear in either list. Each description is linked to location data in one of the other files by the name of the turnpoint, airfield or landout field, so the names must be an exact match in spelling, use of punctuation and capitalisation.

If you're using SeeYou (CUP) format files, this information is also included in the CUP format landout locations file, so you don't need the landout descriptions file. However, if you're using LK8000 or XCSoar you may choose to use the description file because it is shown in a bigger display area and so is usually easier to read.

The file uses a format defined by the authors of XCSoar and LK8000 and is not guaranteed to be useful with any other navigation program or device.

  1. Both XCSoar and LK8000 will truncate or line-wrap overlong lines, which may make the description harder to read. The lines in this file should be OK for use with XCSoar 6.x and LK8000 5.x, but if you spot truncated lines please let us know.
  2. In addition, this file can hold a permanent reference for your home airfield. This is used by both XCSoar and LK8000 though its use depends on the mode the program is running in:
    • Simulate mode: since no GPS data is available in this mode, the program starts up with the home airfield under the glider symbol, ready for simulated local soaring.
    • Fly mode: If there is no defined or default task, your home airfield is automatically selected as the default destination. This is useful for local soaring.


There should be no adverse interaction with later revisions to the BGA turnpoints file, but note that:

  1. Turnpoints added to the BGA list and that are also landout fields will be displayed with the standard BGA turnpoint descriptions if:
    1. They do not have an entry in the UK Landouts Database.
    2. A SeeYou (CUPS) format landouts file is being used.
  2. If a BGA turnpoint is removed or renamed the landout description will become inaccessible unless the corresponding entry in the main UK Landouts Database is changed to match. If you spot any of these, please let us know.
  3. The UK Landouts Database is built against the entire BGA turnpoint list after TPSelect has exported it in the target turnpoint format. This means that descriptions of landout fields that are also BGA turnpoints will not be accessible if you only use a subset of the BGA turnpoints list that excludes them.


The XCSoar and LK8000 data sources page contains links to downloadable static files containing:

The Winpilot (DAT) version was designed for LK8000 and XCSoar, but should also work with any navigation device that can use Winpilot (DAT) turnpoint files. The SeeYou (CUP) format version should be usable with any navigation device that can use CUP format turnpoint files. Download the files you need from XCSoar and LK8000 data sources. You should have:

  1. a landout location file
  2. the matching landout description file. This file is used by LK8000 and XCSoar. Other navigation devices may also be capable of using it, but you'll need to check.
  3. bga_20nnx.dat or bga_20nnx.cup, the current BGA turnpoint file, where nn is the year and x is a letter starting from 'a' that distinguishes versions released during the year. You need the DAT file if you're using the Winpilot (CAI) landout file or the CUP file if you're using the CUP landout file. These files can be downloaded with the landouts database or customised by installing and running the TpSelect application.

Files 1 and 2 should have the same date and timestamp. Preferably, file 3 should not be more recent than the other two files; see the Caveats given above for the reasons for this statement, However, as the landout fields affected by this are probably gliding sites, their landout descriptions will cover details of local landing patterns and areas that should not be overflown. The fact that this turnpoint is landable should be obvious if you look out the window.

Manual customisation

This is needed if you choose to download the static fileset. It involves tagging the main turnpoint on your home field as the XCSoar and LK8000 'HOME' field. As downloaded, this is set to GRL (Gransden Lodge). The steps to change this are:

  1. Open the landout descriptions file with a text editor. If you're running Windows, use Wordpad, PFE or an equivalent text editor. Linux users will probably use gedit, emacs or vim.
  2. Search the file for =HOME and delete those 5 characters.
  3. Search the file for the turnpoint that will become your HOME location.
  4. If you find it, add '=HOME' immediately to the left of the final ']' character so it looks like the GRL entry did.
  5. If you don't find it, add a line like this:
    after the last line in the file and follow it with a blank line. turnpoint is, of course, the name of your chosen turnpoint copied exactly as it is written in the BGA turnpoint file.
  6. Save and close the file.


LK8000 and XCSoar

Copy all three files into the appropriate directory in your navigation instrument. If you're running XCSoar they should go into XCSoarData and if you're running LK8000 they go in LK8000\_Waypoints. Now start the program in Simulate mode and go into page one of Setup System. Configure the files as shown:

File type Winpilot (CAI) file name SeeYou (CUP) file name XCSoar box LK8000 box
BGA turnpoints bga_20nnx.dat bga_20nnx.cup Waypoints Waypoints 1
Landout locations cgc_field_book.dat or uk_landouts.dat cgc_field_book.cup or uk_landouts.cup More waypoints Waypoints 2
Landout field description cgc_field_book.txt or uk_landouts.txt cgc_field_bookCUP.txt or uk_landoutsCUP.txt Waypoint details Waypoint notes

After restarting your program, you should now see landout fields appear in the map display. When you look at their details, either by clicking on them or via the turnpoint selection page, you should be able to see all the information recorded against them as well as the description, which lists radio frequencies, if available, runway directions and dimensions as well as warnings about obstructions and mandatory approach details.

If you set your HOME airfield and started the program in Simulate mode, your home airfield should be under the glider symbol on the map.

Other devices that use SeeYou (CUP) files

Install the landout locations file as the second waypoints file.