1. MF Non-Directional Beacon (NDB);

2. VHF Direction-Finding Station (VDF);

3. Approach Radar (RAD);

4. Precision Approach Radar (PAR) at certain military aerodromes;

5. Instrument Landing System (ILS);

6. VHF Omni-directional Radio Range (VOR);

7. Distance Measuring Equipment (DME).

1. The range promulgated for UK NDBs is based on a daytime protection ratio between wanted and unwanted signals that limits bearing errors at that distance to ±5 degrees or less. At ranges greater than those promulgated bearing errors will increase. Adverse propagation conditions particularly at night will also increase bearing errors.

2. NDBs provided for use as approach aids, during the notified hours of ATS, at aerodromes for which instrument approach procedures are published in the AD section are notified in this AIP as locator beacons (L). Most locator beacons continue to transmit a usable signal outside notified hours, these signals are provided for the purposes of navigational aid only. Aerodrome NDBs not notified as locator beacons are provided for navigational use only.

3. Details of the Maritime Radio beacons (NDB) are published by the Hydrographer of the Navy, Hydrographic Department (MOD), Taunton, Somerset TA1 2DN, and are available from Admiralty Chart Agents.

1. VDF bearings are classified as follows:

   1. Class A: accurate to within ±2 degrees;

   2. Class B: accurate to within ±5 degrees;

   3. Class C: accurate to within ±10 degrees.

2. VDF bearing information will only be given when conditions are satisfactory. Normally no better than Class B bearing will be available.

1. The VHF communications frequencies for use with Approach Radars are listed in AD 2 item 2.18

1. Aircraft overflying the localizer or manoeuvring on or near the runway may disturb the ILS guidance signals. ATC will apply increased separation and such other measures considered necessary to prevent interference during Category II and III operations.

2. Such measures will also be applied at the discretion of ATS when requested by pilots wishing to use Category II and III landing procedures when meteorological conditions do not necessitate them

3. For all civil ILS notified in AD 2 item 2.19 the Localizer usable coverage sector is ±35° about the nominal course line and the glidepath provides coverage to the minimum ICAO requirement of 10 NM unless otherwise stated. Pilots using these instrument landing systems are advised not to attempt to intercept and follow the glidepath until the aircraft is established on the Localizer centre-line. Due to the presence of false courses on some localizers operating in the UK, pilots are advised not to attempt to use any ILS facility outside ±35° of the front course line. This advice is in addition to the notes promulgated in AD 2 item 2.19 for individual ILS.

4. Steep Angle facilities listed in the ILS entries in AD 2 item 2.19 provide a more limited coverage than that described in paragraph 1.5(c), the Localizer usable coverage sector being limited to 10 NM at ±35° and to 18 NM at ±10°. The glidepath provides coverage to 8 NM.

5. Although all MoD ILS facilities are technically classed as ‘uncategorised’, they are flight checked to ICAO CAT I standards. However, pilots of aircraft cleared to carry out practice auto-coupled approaches with the appropriate visual references to below CAT I limits are to note the following: Unless specifically promulgated otherwise, ILS facilities at MoD airfields are not capable of providing the required quality of beam structure to enable auto-coupled approaches to be continued below the minimum CAT I Decision Height.

1. A DME facility at an aerodrome, which is frequency paired with the ILS, is arranged to give zero range indication with respect to the threshold of the runway with which it is associated and precise ranges will only be indicated when aircraft are in line with the runway on the approach path. As a consequence of this, if used other than in accordance with promulgated procedures indicated range should be taken as an approximate range to the aerodrome.

1. The Designated Operational Coverage promulgated for UK VOR and DME together with details of any unsatisfactory conditions known to exist, are listed in AD 2 item 2.19 or at ENR 4.1.

2. Because inaccurate bearing information may be radiated by a VOR during a changeover to the standby transmitter, no identification signal is radiated until the changeover is completed. Pilots are advised to continually monitor the identification signal throughout a VOR approach.

3. Where a VOR and TACAN are frequency paired, but not within the co-location limit of 600 M, the last letter of the TACAN identification will be a 'Z'. Civil Pilots are advised not to make operational use of distance information provided by Military TACAN facilities promulgated as unreliable and/or transmitting a series of dots after the identification code.

4. Where an en-route VOR or VOR/DME facility has an instrument approach procedure published in the AD section, a note in Column 7 at ENR 4.1 indicates the aerodrome so served. The hours of service as an approach aid are within the notified hours of the Air Traffic Services at the aerodrome served.

1. Aerodrome DME referred to in an instrument approach procedure published in the AD section is provided for use as an approach aid during the notified hours of ATS only. Most DME continue to transmit outside ATC notified hours for the purpose of navigational aid only.

2. Aerodrome DME with their zero range off-set to occur at specific runway thresholds are identified by comments in Column 7 at AD 2 item 2.19. Any DME range indications observed when between runway thresholds should be ignored. Other aerodrome DME indicate true slant range from aircraft to DME site.

1. Facilities are provided to meet the Air/Ground communications requirements of the Air Traffic Services described in the AIP and the Emergency Services detailed at paragraph 3.2.6. These services include coverage over the greater part of the United Kingdom Flight Information Regions above 3000 FT. Some limited cover may be possible below this altitude.

2. United Kingdom Air/Ground facilities will communicate with aircraft on frequencies within the Aeronautical Mobile (R) Service which has been allocated to the band 118 to 136.975 MHz.

3. United Kingdom airspace utilises 8.33 kHz channel spacing in line with Assimilated Regulation (EU) No. 1079/2012. All airspace users, unless otherwise notified, in ENR 1.8, will be required to be equipped with 8.33 kHz VCS capable radios.

4. The language to be used when communicating on the United Kingdom Aeronautical Mobile Service is English.

5. Procedures to follow in the event of Radio failures are contained in the AD and ENR Sections.

6. At a civil aerodrome the following words in a callsign identify an Air Traffic Control Service: TOWER, APPROACH, GROUND, ZONE, RADAR, DIRECTOR, DELIVERY.

7. In a callsign, only the word INFORMATION is used to identify an Aerodrome Flight Information Service, Aerodrome Terminal Information Service or Area Flight Information Service.

8. In a callsign, only the word RADIO is used to identify an aerodrome Air/Ground communication service.

1. Geographical separation between international services using the same or adjacent frequencies is determined so as to ensure as far as possible that aircraft at the limits of height and range to each service do not interfere with one another. In the case of en-route sectors these limits correspond to that of the ATC sector concerned and those for international aerodrome services are appropriate a radius of 25 NM up to a height of 4000 FT (TWR) or 10000 FT (APP).

2. Except in emergency, or unless otherwise instructed by the Air Traffic Services, pilots should observe these limits. Services other than international services are provided on frequencies which are shared between numerous ground stations and have to operate to a higher utilisation in order to satisfy the demand for frequencies. Pilots using these frequencies should assist in reducing interference by keeping communications to a minimum and by limiting the use of aircraft transmitters to the minimum height and distance from the aerodrome that are operationally necessary. In the case of TWR, AFIS and A/G facilities, communications on these frequencies should be restricted as far as possible to heights up to 1000 FT in the immediate vicinity of the aerodrome concerned and in any event within 10 NM and 3000 FT.

1. At locations having no ground radio facilities a VHF channel is available to assist departing helicopters.

2. Conditions of use are:

   1. It shall only be used at locations having no radio facilities. If another VHF assignment is valid for that location, it must be used even outside the normal operating hours;

   2. Transmissions shall occur only when helicopters are below 500 FT AGL;

   3. Helicopters approaching a site should monitor the channel. Blind transmissions are not permitted, except where Pilot Controlled Lighting is used.

3. Departing helicopters shall state:

   1. 'To all stations';

   2. The callsign of the aircraft;

   3. The location either by name or by reference to a readily identifiable feature;

   4. The direction and height of the intended departure.

4. The channel assigned is 122.955 and shall be known as 'DEPCOM'.

5. Where Pilot Controlled Lighting systems are used, arriving helicopters may transmit a sequence of microphone clicks to activate the ground lighting system, within 6 NM from the ground location. Pilot Controlled Lighting systems using the common channel must not transmit from the ground.

1. At aerodromes having no notified ground radio facilities a VHF channel is available to assist pilots to avoid potential collisions between arriving and departing aircraft. Pilots may use this channel to broadcast their intentions for safety purposes.

2. The channel assigned is 135.480 and is known as 'SAFETYCOM'.

3. The conditions of use are:

   1. SAFETYCOM shall only be used at aerodromes having no notified ground radio facility. If a VHF channel is notified for a location, that notified channel must be used even outside the notified operating hours.

   2. Transmissions shall be made only within a maximum range of 10 NM of the aerodrome of intended landing, and below 2000 FT above the aerodrome elevation.

   3. SAFETYCOM shall only be used to transmit information regarding the pilot's intentions, and there should be no response, except where the pilot of another aircraft also needs to transmit his intentions or, exceptionally, has information critical to the safety of an aircraft in a condition of distress or urgency.

   4. Phraseology is to comply with the requirements of CAP 413 (Radiotelephony Manual) Chapter 4 Section 6.

   5. SAFETYCOM is not to be used for the conduct of formation flights unless landing at or taking off from an aerodrome for which no other frequency is notified and within the limits specified at sub paragraph (ii).

   6. Pilots operating at aerodromes without a notified channel are recommended to use SAFETYCOM, but its use is not mandatory. However, if pilots choose to use it, they must make the transmissions listed in CAP 413 as 'essential'. It must not be assumed that all other pilots in the vicinity are monitoring the channel and, as at all other times, pilots must maintain a good lookout.

   7. No air traffic service is associated with SAFETYCOM. Where an aerodrome lies within controlled airspace, pilots must establish contact with the responsible air traffic services unit, and obtain clearance prior to entering controlled airspace.

   8. Information transmitted on SAFETYCOM confers no priority or right of way. Pilots shall comply with the Rules of the Air Regulations, including the provisions in relation to avoiding aerial collisions.

4. Unless specifically approved by the CAA, SAFETYCOM is not to be used for special events as defined in CAP 403 (Flying Displays and Special Events: A Guide to Safety and Administrative Arrangements). Channels for special events should continue to be requested through existing contacts.

3.2.5  VHF Low Level Common Frequency for use within the UK Low Flying System (UKLFS)

1. Available for use by all aircrew, military and civilian, operating in Class G airspace at or below 2000 FT AGL in the UKLFS and should be monitored whenever possible.

2. Pilots should use this channel to broadcast their intentions to help improve situational awareness between all aircrew operating in the same area.

3. The channel assigned is 130.490 and shall be known as the “LL-Common Frequency”.

4. The conditions of use are:

   1. Pilots should make use of the LL Common Frequency only when not in receipt of a Lower Airspace Radar Service or other Air Traffic Service, or when operating outside an area where a Frequency Monitoring Code and associated ATC frequency/channel is used.

   2. Pilots should make blind calls. To prevent clutter the channel must not be used as a chat channel.

   3. Transmissions should be accurate, clear and concise.

5. Transmission Timing:

   1. When safe and suitable.

   2. When entering/exiting the UKLFS.

   3. At turning points or significant heading changes.

   4. Approaching well-known and recognisable physical features.

   5. Any time it is considered beneficial to the safety of the aircraft.

6. Blind call Content:

   1. Call Sign.

   2. Aircraft type (and number, in case of formations).

   3. Position in relation to reference points immediately identifiable to other pilots (using cardinal or inter-cardinal directions).

   4. Altitude.

   5. Heading.

   6. Next significant reference point.

7. Details of the UKLFS are shown in ENR 6-20 and ENR 6-21.

1. An emergency communications and aid service is continuously available on 121.500 from the Distress and Diversion (D & D) section located at RAF (U) Swanwick.

2. Operational control is exercised from RAF (U) Swanwick D & D, callsign 'LONDON CENTRE'. The service provides coverage over the greater part of the United Kingdom above 3000 FT. In addition, the stations and units listed at GEN 3.6 have the capability of providing an emergency service on 121.500. (For further details see GEN 3.6, paragraph 6.5).

3. Pilots of aircraft in emergency and using 121.500 should broadcast the initial 'MAYDAY' or 'PAN PAN' call. The Air Traffic Controller at Swanwick will answer the call and initiate appropriate action. (For use of SSR in emergency see ENR 1.6).

4. If the emergency is ended the pilot should inform the controlling authority of the fact and state his intentions before leaving the frequency. This will ensure that any action to alert diversion aerodromes or other assistance will be cancelled.

5. Details of the ATSUs with Emergency Facilities are shown at GEN 3.6.

1. Whenever an emergency has been declared at an aerodrome where this service is notified, aircraft may communicate direct with the Fire Service in attendance with the following conditions:

   1. The service must be used only when the aircraft is on the ground.

   2. Contact with ATC, on the appropriate frequency must be maintained.

   Note: This service is only available by arrangement via ATC and may only be used for the duration of the emergency. The fire service does not normally monitor this service at other times.

2. The availability of this service is indicated in the AD section at item 2.18. It should be noted that the service provided is not an Air Traffic Service.

Pilot Controlled Lighting is used at certain aerodromes for pilots to remotely turn on Aeronautical Ground Lighting outside operating hours, normally using an existing ATS or AGCS VHF channel.

Pilots or organisations using PCL must seek agreement from the relevant aerodrome authority.

1. The Operational Telephone Network for use by ATC and supporting operational services;

2. the Administrative Telephone Network for use by authorised agencies connected with air traffic operations;

3. the Aeronautical Fixed Telecommunications Network (AFTN), for the exchange of messages between aeronautical fixed stations within the network.

1. by complete removal;

2. by radiating a continuous tone.

Reports should include the following information:

1. Frequency on which interference occurred;

2. Approximate position and height of aircraft;

3. aircraft registration letters;

4. date and time of interference;

5. description of interfering signal e.g. music, speech, language, etc.