ATS Surveillance Services and Procedures

ENR 1.6 ATS SURVEILLANCE SERVICES AND PROCEDURES

1.6.1 Primary Radars

1. General

1.1 ATS surveillance units form part of their parent ATS unit. Provision of surveillance services is conditional on operational availability and approval; radar service is currently suspended as stated above.

1.2 Factors such as surveillance coverage, controller workload, and equipment capabilities affect these services. The ATS surveillance controller will determine whether radar/surveillance services can be provided or continued in any specific case.

1.3 Within Damascus FIR, procedural service is provided during the radar suspension notified by A0270/26.

1.4 The provision allowing omission of position reports applies only to aircraft actually receiving an ATS surveillance service and subject to ATC instructions. It does not establish an exemption from position reporting during procedural service.

1.5 Pilots will be advised by ATC on the commencement, identification, and termination of ATS surveillance (radar) services.

2. Application of ATS Surveillance Services

2.1 When available and approved, ATS surveillance services are subject to ICAO Doc 4444 (PANS-ATM), Chapter 8. This reference does not establish current service availability.

2.2 Damascus ACC provides procedural service during the suspension. The historical radar unit/call sign description does not indicate an available radar service.

3. RADAR COVERAGE

Radar service suspended throughout Damascus FIR — NOTAM A0270/26. The nominal equipment ranges listed below are retained as equipment information only; they do not establish coverage, availability, or approved separation capability.

4. APPLICATION OF RADAR CONTROL SERVICE

4.1 Radar identification is achieved in accordance with the provisions specified in ICAO Doc 4444 (PANS-ATM).

4.2 Radar separation, monitoring and vectoring are not available under the current radar suspension. Resumption and the applicable service area require an authoritative service-restoration notice and approved procedures.

4.3 Radar separation minima are not applicable during the notified radar suspension. The previously displayed 20 NM / 10 NM figures must not be used as procedural minima; see paragraph 3.2.8 for the source-specific procedural arrangements.

1.6.2 SECONDARY SURVEILLANCE RADAR (SSR)

1 Operating Procedures

1.1 Except as provided below, pilots shall operate transponders and select modes and codes in accordance with ATC instructions. In particular, when entering the Damascus FIR, pilots who have already received specific instructions from ATC concerning the transponder setting shall maintain that setting until otherwise instructed. Mode C (altitude reporting) shall be selected at all times unless otherwise instructed by ATC or under emergency conditions.

1.2 SSR Code Allocation System:

a) The Damascus Flight Information Region (FIR) operates in accordance with the ICAO Regional SSR Code Allocation Plan (ORCAM).

b) Aircraft entering the Damascus FIR shall retain the SSR code previously assigned by Air Traffic Control (ATC) in the adjacent departure/originating FIR, and shall not change this code except in the following circumstances:
    1) When specifically instructed by Damascus Area Control Centre (ACC); or
    2) In the event of an emergency (selecting 7500, 7600, or 7700).

c) Transit/Overflight SSR codes (Mode A: 5700 to 5777) will be assigned by Damascus ACC only when an aircraft enters the FIR without a previously allocated code, when code conflicts need to be resolved, or for aircraft departing Damascus FIR to destinations outside the airspace.

d) Domestic SSR codes (Mode A: 3000 to 3077) will be assigned by Damascus ACC for flights operating entirely within the Damascus FIR. Source: permanent NOTAM A0043/23.

2 Emergency Procedures

2.1 If the pilot of an aircraft encountering a state of emergency has previously been directed by ATC to operate the transponder on a specific code, this code setting shall be maintained until otherwise advised by ATC. In all other emergency circumstances, the transponder shall be set as follows:
    a) Mode A/3 Code 7500: Unlawful interference (Hijacking).
    b) Mode A/3 Code 7600: Radio communication failure.
    c) Mode A/3 Code 7700: Emergency (General emergency).

2.2 Notwithstanding the procedure in paragraph 2.1 above, a pilot may select Mode A/3 Code 7500, 7600, or 7700, as appropriate, whenever the nature of the emergency is such that this appears to the pilot to be the most suitable course of action.

3. RADAR AND RADIO FAILURE PROCEDURES

3.1 Radar Failure

3.1.1 In case of radar failure or loss of radar identification, instructions will be issued by ATC to restore non-radar standard separation, and the pilot will be instructed to communicate with the parent ATS unit.

3.2 Radio Failure

3.2.1 Aircraft Not Equipped with a Transponder:
The radar controller will establish whether the aircraft radio receiver is working by instructing the pilot to perform a turn, maintain the new heading for a specified period of time, and then resume normal navigation. The magnitude of the turn will be such as to enable identification to be achieved should the aircraft not previously have been identified. The direction of the turn will be determined by operational requirements.

3.2.2 Aircraft Equipped with a Transponder:
The radar controller will establish whether the aircraft radio receiver is working by instructing the pilot to perform one or more of the following:
a) Change transponder mode;
b) Change transponder code;
c) Operate the SPI feature.

The method used will be such as to enable identification to be achieved should the aircraft not previously have been identified.

3.2.3 Action by Radar Control:
a) If subsequent movement of the radar echo or radar responses indicate that the aircraft radio receiver is working, the radar controller will assume or resume radar control, as the case may be, and continue to pass instructions as for a normal radar service.
b) If subsequent movements of the radar echo or radar responses indicate that the aircraft radio receiver is not working, the radar controller will take action, according to the circumstances prevailing, as detailed in paragraphs 3.2.3 c) and 3.2.3 d) below, as appropriate.
c) If, prior to the communication failure, the radio failure aircraft was identified, the radar controller will ensure that all known traffic is provided with a minimum of 20 NM horizontal radar separation from the radio failure aircraft, performing identification as necessary, until such time as the radio failure aircraft leaves radar coverage or lands.
d) If, prior to the communication failure, the radio failure aircraft was not identified or its position is not known, the radar controller will continue to provide a radar service to identified aircraft only, provided that primary radar coverage is sufficient to ensure a minimum of 20 NM horizontal radar separation from all unknown traffic, until such time as the radio failure aircraft is known to have left the area or landed.

3.2.4 Action by Aircraft:
a) Aircraft able to receive transmissions from radar control will comply with such instructions as are issued, acknowledging as indicated by the radar controller, as detailed in paragraph 3.2.3 a) above.
b) Aircraft not able to receive transmissions will comply with the ICAO radio communication failure procedures as prescribed in Annex 2 (3.6.5.2), Doc 4444 PANS-ATM (Chapter 15.2), and those detailed in specific aerodrome AIP sections (AD 2.OSDI for Damascus International Airport and AD 2.OSAP for Aleppo International Airport).
c) It is essential that the procedures as detailed above are rigidly adhered to, as the actions by radar control are based upon aircraft compliance therewith; failure to comply may result in a loss of separation.

3.2.5 Action in the Event of Air-Ground Communication Failure:
As soon as it is known that two-way communication has failed, ATC shall maintain separation between the aircraft experiencing communication failure and other aircraft based on the assumption that the aircraft will operate in accordance with paragraphs 3.2.6 and 3.2.7.

Note: The following expands upon the requirements contained in ICAO Annex 2 (3.6.5.2) and PANS-ATM (8.8.3 and 15.2) and specifies additional details regarding air-ground communications failure within the Damascus FIR.

3.2.6 Visual Meteorological Conditions (VMC):
Except as provided in paragraph 3.2.7, a controlled flight experiencing communication failure in VMC shall:
a) Set transponder to Code 7600;
b) Continue to fly in VMC;
c) Land at the nearest suitable aerodrome; and
d) Report its arrival time by the most expeditious means to the appropriate air traffic control unit.

3.2.7 Instrument Meteorological Conditions (IMC): The surveillance-specific seven-minute communication-failure procedure previously reproduced here is not a declaration of the applicable procedural-service procedure during radar suspension. Refer to ENR 1.3, applicable published communication-failure procedures and current NOTAMs. The complete national communication-failure procedure and cross-references require ACC validation before surveillance service is restored.

Note: Pilots are reminded that the aircraft may not be in an area of secondary surveillance radar coverage throughout the entire Damascus FIR.

3.2.8 Procedural separation — NOTAM A0152/26:
Transferring ATS units shall apply a minimum of 10 minutes longitudinal separation between successive overflights entering Damascus FIR at the same flight level via the same entry point, same route, same track, or converging traffic flows, unless otherwise coordinated with Damascus ACC.
Under the published temporary route deconfliction measures, Damascus ACC may accept 50 NM longitudinal separation for same-speed aircraft, or 5 minutes longitudinal separation provided the preceding aircraft maintains at least 20 kt higher TAS, in accordance with applicable ICAO procedural separation provisions and subject to prior coordination with Damascus ACC.
These are conditional arrangements for the traffic and coordination circumstances stated in the NOTAM; they are not unconditional minima for all FIR traffic. The former blanket 20 NM / 10 NM procedural figures and 500 ft emergency provision are withdrawn from this summary pending authoritative ACC validation.
Source status: A0152/26 was returned by the FAA search on 23 September 2026; the portal operator confirmed that it remains active on that date. Its issued C) field remains 18 August 2026 at 1600 UTC EST. No replacement end date is assigned here. The notice references A0147/26 and associated temporary route notices A0149/26, A0150/26 and A0151/26; consult subsequent notices and coordinate the applicable arrangements with Damascus ACC.

1.6.3 Automatic dependent Surveillance -Broadcast (ADS-B)

Future aircraft equipment requirement: NOTAM A0272/26 introduces ADS-B OUT 1090ES requirements for IFR flights within Damascus FIR from 1 December 2026 at 0000 UTC. Consult the complete notice for equipment, identification and prior-authorization conditions. This future equipment requirement does not establish that an ADS-B separation service is currently available.

1.6.4 Other relevant information and Procedures

NIL