FAILURE OF NAVIGATION EQUIPMENT
If part of an aircraft's radio navigation equipment fails but two-way communication can still be maintained with ATC, the pilot must inform ATC of the failure and report his altitude and approximate position. ATC may, at its discretion, authorize the pilot to continue his flight in or into controlled airspace. When radar is available it may be used to provide navigational assistance to the pilot.
If no authorization to proceed is given by ATC, the pilot should leave, or avoid controlled airspace and areas of dense traffic, and either
- go to an area in which he can continue his flight in VMC; or (if this is not possible)
- select a suitable area in which to descend through cloud, fly visually to a suitable aerodrome and land as soon as possible.
Before doing so, however he should consult ATC who may be able to give him instructions or advice. He should also take into consideration the latest meteorological information and terrain clearance and should make full use of ground VHF/DF stations. He must at all times keep ATC informed of his intentions.
FAILURE OF TWO-WAY RADIO COMMUNICATION EQUIPMENT
It should be noted that for many aerodromes the radio communication failure procedures published on the following EMERGENCY pages differ from, or amplify, the basic procedures below.
For the purpose of these procedures ATC will expect and IF flight following the ATS route structure to adopt the IMC procedure as detailed below. If there is an overriding safety reason, the pilot may adopt the VMC procedure.
The expression Expected Approach Time (EAT) will either mean an EAT given by the appropriate ATC unit or, if the pilot has been given 'No delay expected', the Estimated Time of Arrival (ETA) over the appropriate designated landing aid serving the destination aerodrome.
Pilots are given an EAT of 'Delay not determined' when the destination runways cannot be used for landing and it is not possible to accurately predict when they become available. In some circumstances an EAT of 'Delay not determined' will also be given when a preceding flight has elected to remain over the holding facility pending an improvement in weather conditions at the destination. If 'Delay not determined' has been given, do not attempt to land at the destination aerodrome, divert to the alternate destination specified in the current flight plan or another suitable airfield.
Essential information may be relayed by ATC using the ACARS/data link. Pilots may endeavour to use alternative methods for communicating with ATC such as HF. The Distress and Diversion Cells (D&D) serving the London FIR/UIR and the Scottish FIR/UIR may be contacted by phone by aircraft that have approved installations that can access the UK telephone network. The telephone number is:
London D&D Tel: 01489-612406
VISUAL METEOROLOGICAL CONDITIONS
VFR FLIGHT
When VMC can be maintained, the pilot should set transponder on Mode A, code 7600 with Mode G and land at the nearest suitable aerodrome. Pilots should take account of visual landing aids and keep watch for instructions as may be issued by visual signals from the ground. The pilot should report arrival to appropriate ATC unit as soon as possible.
When VMC cannot be maintained, the pilot should adopt the procedures for IMC as detailed below:
IFR FLIGHT
When VMC can be maintained, the pilot should set transponder on Mode A, code 7600 with Mode C and land at the nearest suitable aerodrome. Pilots should take into account visual landing aids and keep watch for instructions as may be issued by visual signals from the ground. The pilot should report arrival to appropriate ATC unit as soon as possible.
If it does not appear feasible to continue the flight in VMC, or it would be inappropriate to follow this procedure, the pilot should adopt the IMC procedures as detailed below.
INSTRUMENT METEOROLOGICAL CONDITIONS
A flight experiencing communications failure in IMC during an approach directed by radar shall:
- Operate secondary radar transponder on Mode A code 7600 with Mode C.
- Continue either visually, or by means of promulgated Initial Approach Procedures and an appropriate approved final approach aid, to land. If this is not practical, carry out the missed approach procedure and continue to a holding facility appropriate to the airfield of intended landing for which an instrument approach is notified and then carry out that procedure.
Except where communications failure occurs during an approach directed by radar, a flight experiencing communication failure in IMC shall:
- Operate secondary radar transponder on Mode A, code 7600 with Mode C. Maintain for a period of 7 minutes, the current speed and last assigned level or minimum safe altitude, if this higher. The period of 7 minutes begins when the transponder is set to 7600 and this should be done as soon as the pilot has detected communications failure. If failure occurs when the aircraft is following a notified departure procedure such as a Standard Instrument Departure (SID) and clearance to climb, or rerouting instructions have not been given, the procedure should be flown in accordance with the published lateral track and vertical profile, including any stepped climbs, until the last position, fix or way point, published for the procedure, has been reached. Then, for that part of the period of 7 minutes that may remain, maintain the current speed and last assigned level or minimum safe altitude, if higher. Following the period of 7 minutes, adjust the speed and level in accordance with the current flight plan and continue the flight to the appropriate designated landing aid serving the destination aerodrome. Attempt to transmit position reports and altitude/flight level on the appropriate frequency when over routine reporting points.
- If being radar vectored, or proceeding offset according to RNAV, without having been given a specified limit, pilots are to continue with ATC instructions last acknowledged for 3 minutes only, before returning to their flight planned route. Pilots should ensure that they remain at, or above, the minimum safe altitude.
- Comply with the loss of communications procedures notified for the destination aerodrome. Arrange the flight to arrive over the appropriate designated landing aid serving the destination aerodrome as closely as possible to the ETA last acknowledged by ATC. If no such ETA has been acknowledged, the pilot should use an ETA derived from last acknowledged position report and the flight-planned times for the subsequent sections of the flight. Arrange the flight to arrive over the appropriate designated landing aid serving the destination aerodrome at the highest notified minimum sector altitude taking account of enroute terrain clearance requirements. If following a notified Standard Arrival Route (STAR), after the 7 minute period detailed above has been completed, pilots should arrange descend as close as possible to the published descent planning profile. If no descent profile is published, pilot should arrange descent to be at the minimum published level at the appropriate designated initial approach fix.
- On reaching the appropriate designated landing aid serving the destination aerodrome, begin further descent at the last acknowledged EAT. If no EAT has been acknowledged, the descent should be started at the ETA calculated as described before, or as close as possible to this time. If necessary remain in the holding pattern until the minimum holding level published for this facility, has been reached. The rate of descent in holding patterns should not be less than 500ft/min. If 'Delay not determined' has been given, do not attempt to land at the destination aerodrome, divert to the alternate destination specified in the current flight plan or another suitable airfield.
- Carry out the notified instrument approach procedure as specified for the designated navigational aid, if possible, land within 30 minutes of the EAT or the calculated ETA. When practicable, pilots should take account of visual landing aids and keep watch for instructions that may be issued by visual signs from the ground.