ENR 1  General Rules and Procedures

ENR 1.6   RADAR SERVICES AND PROCEDURES

1.GENERAL
Radar units are operated as an integral part of the parent ATS unit and provide radar service to aircraft, to the maximum extent practicable, to meet the operational requirements. Factors, such as radar coverage, controller workload and equipment capabilities, affect these services, and the radar controller will determine whether he is able to provide, or continue to provide radar services in any specific case.
Pilots will be advised on commencement and termination of radar services.
2.RADAR COVERAGE
Within the airspace of The Gambia and also in the Banjul CTR primary radar coverage is not available.
No SSR coverage is available within the Dakar Flight Information Region and the Banjul CTR. Charts depicting the coverages of the radar are not published.
3.PRIMARY RADAR
3.1The Application of Radar Control Service
3.1.1Radar Failure
In the event of radar failure or loss of radar identification, instructions will be issued to restore non-radar standard separation and the pilot will be instructed to communicate with the parent ATS unit.
3.1.2Radio Failure
The radar controller will establish whether the aircraft radio receiver is working by instructing the pilot to carry out a turn or turns. If the turns are observed, the radar controller will continue to provide radar service to the aircraft.
If the aircraft’s radio is completely unserviceable, the pilot should carry out the procedures for radio failure according to ICAO provisions. If radar identification has already been established, the radar controller will vector other identified aircraft clear of its track until the aircraft leaves radar control.
4.SECONDARY SURVEILLANCE RADAR (SSR)
4.1Emergency Procedures
4.1.1If the pilot of an aircraft encountering a state of an emergency has previously been directed by ATC to operate the transponder on a specific code, this code setting will be maintained until otherwise advised. In all other emergency circumstances, the transponder will be set as follows:
  1. Mode A/3 code 7500 - Unlawful interference
  1. Mode A/3 code 7600 - Radio communication failure.
  1. Mode A/3 code 7700 - Other states of emergency
4.1.2Aside the procedure in paragraph 4.1.1 above, a pilot may select mode A/3 code 7500, 7600 or 7700, as appropriate, whenever the nature of an emergency is such that this appears to him to be the most suitable course of action.