ENR 1.12 INTERCEPTION OF CIVIL AIRCRAFT

1. GENERAL

The following procedures and visual signals apply over the territory and territorial waters of the Sultanate of Oman in the event of interception of an aircraft.

1.1 An aircraft which is intercepted by another aircraft shall immediately:

a) follow the instructions given by the intercepting aircraft, interpreting and responding to visual signals in accordance with the specifications;

b) notify, if possible, the ATS unit responsible for the airspace in which the aircraft is flying;

c) make a general call on the emergency frequency 121.500 MHz to attempt to establish radio communication with the intercepting aircraft or with the appropriate intercept control unit, giving the identity of the intercepted aircraft, the nature of the flight, and if no contact has been established and it is practical, repeat the call on the emergency frequency 243.000 MHz;

d) if equipped with SSR transponder, select Mode A, Code 7700, unless otherwise instructed by the appropriate ATS unit.

1.2 If radio contact is established during interception but communication in a common language is not possible, attempts shall be made to convey instructions, acknowledgment of instructions and essential information by using the phrases and pronunciations in the following table and transmitting each phrase twice:

Phrase	Pronunciation¹	Meaning
CALL SIGN (call sign²)	KOL -SA-IN (call sign)	My call sign is (call sign)
WILCO	VILL -KO	Understood. Will comply
CAN NOT	KANN NOTT	Unable to comply
REPEAT	REE-PEET	Repeat your instruction
AM LOST	AM LOSST	Position unknown
MAYDAY	MAYDAY	I am in distress
HIJACK³	HI-JACK	I have been hijacked
LAND (place name)	LAAND (place name)	I request to land at (place name)
DESCEND	DEE SEND	I require descend

1.2.1 The following phrases shall be used by the intercepting aircraft and transmitted twice in the circumstances described in the preceding paragraph:

Phrase	Pronunciation¹	Meaning
CALL SIGN	KOL -SA-IN	What is your call sign?
FOLLOW	FOL -LO	Follow me
DESCEND	DEE SEND	Descend for landing
YOU LAND	YOU LAAND	Land at this aerodrome
PROCEED	PRO-SEED	You may proceed

¹ Syllables to be emphasized are printed in bold letters.

² The call sign required to be given is that used in radiotelephony communications with air traffic services units and corresponding to the aircraft identification in the flight plan.

³ Circumstances may not always permit, nor make desirable, the use of the phrase "HIJACK".

1.3 If any instructions received by radio from any sources conflict with those given by the intercepting aircraft by visual signals, the intercepted aircraft is required to request immediate clarification while continuing to comply with the visual instructions given by the intercepting aircraft.

1.4 If instructions received by radio from any source conflict with those given by the intercepting aircraft by radio, the intercepted aircraft is required to request immediate clarification while continuing to comply with the radio instructions given by the intercepting aircraft.

1.5 The visual signals detailed in the table "SIGNALS FOR USE IN THE EVENT OF INTERCEPTION" shall be used.

2. SIGNALS FOR USE IN THE EVENT OF INTERCEPTION

A. Signals Initiated by the Intercepting Aircraft and Responses by the Intercepted Aircraft
	Signals/Commands of INTERCEPTING Aircraft		Signals/Responses of INTERCEPTED Aircraft
Series	Meaning	Actions by Intercepting Aircraft	Meaning	Actions by Intercepted Aircraft
1	You have been intercepted. Follow Me.	AIRPLANES AND HELICOPTERS: DAY - Rocking wings from a position in front and, normally, to the left of the intercepted aircraft and, after acknowledgment, a slow level turn, normally to the left, on the desired heading. NIGHT - Same actions as by day and, in addition, flashing navigational lights at irregular intervals. Note 1: Meteorological conditions or terrain may require the intercepting aircraft to take up a position in front and to the right of the intercepted aircraft and to make the subsequent turn to the right. Note 2: If the intercepted aircraft is not able to keep pace with the intercepting aircraft, the latter is expected to fly a series of race-track patterns and to rock its wings each time it passes the intercepted aircraft.	Understood, will comply.	AIRPLANES: DAY - Rocking wings and following the intercepting aircraft. NIGHT - Same actions as by day and, in addition, flashing navigational lights at irregular intervals. HELICOPTERS: DAY OR NIGHT - Rocking aircraft, flashing navigational lights at irregular intervals and following the intercepting aircraft. Note: Additional action may be taken by the intercepted aircraft as prescribed above.
2	You may proceed.	AIRPLANES AND HELICOPTERS: DAY OR NIGHT - An abrupt breakaway manoeuvre from the intercepted aircraft consisting of a climbing turn of 90 degrees or more without crossing the line of flight of the intercepted aircraft.	Understood, will comply.	AIRPLANES: DAY OR NIGHT - Rocking wings. HELICOPTERS: DAY OR NIGHT - Same as Series 1 helicopter signal.
3	Land at this aerodrome.	AIRPLANES AND HELICOPTERS: DAY - Circling aerodrome, lowering landing gear and overflying runway in direction of landing or, if the intercepted aircraft is a helicopter, overflying the helicopter landing area. NIGHT - Same as in the daytime and, in addition, showing steady landing lights.	Understood, will comply.	AIRPLANES: DAY - Lowering landing gear, following the intercepting aircraft and, if after overflying the runway landing is considered safe, proceeding to land. NIGHT - Same as in the daytime and, in addition, showing steady landing lights (if carried). HELICOPTERS: DAY OR NIGHT - Following the intercepting aircraft and proceeding to land, showing steady landing lights (if carried).

B. Signals Initiated by the Intercepted Aircraft and Responses by the Intercepting Aircraft
	Signals/Responses of INTERCEPTED Aircraft		Signals/Commands of INTERCEPTING Aircraft
Series	Meaning	Actions by Intercepted Aircraft	Meaning	Actions by Intercepting Aircraft
4	The aerodrome you have designated is inadequate for landing.	AIRPLANES: DAY - Raising the landing gear while passing over the landing runway at a height exceeding 1000 FT but not exceeding 2000 FT above the aerodrome level, and continuing to circle the aerodrome. NIGHT - Flashing landing lights while passing over the landing runway at a height exceeding 1000 FT but not exceeding 2000 FT above the aerodrome level, and continuing to circle the aerodrome. If unable to flash landing lights, flash any other lights available.	Understood, follow me. Understood, you may proceed.	AIRPLANES: DAY OR NIGHT - If it is desired that the intercepted aircraft follow the intercepting aircraft to an alternate aerodrome, the intercepting aircraft raises its landing gear and uses the Series 1 signals prescribed for intercepting aircraft. DAY OR NIGHT - If it is decided to release the intercepted aircraft, the intercepting aircraft uses the Series 2 signals prescribed for intercepting aircraft.
5	Cannot comply.	AIRPLANES: DAY OR NIGHT - regular switching on and off of all available lights but in such a manner as to be distinct from flashing lights.	Understood.	AIRPLANES: DAY OR NIGHT - Use Series 2 signals prescribed for intercepting aircraft.
6	In distress.	AIRPLANES AND HELICOPTERS: DAY OR NIGHT - Irregular flashing of all available lights.	Understood.	AIRPLANES AND HELICOPTERS: DAY OR NIGHT - Use Series 2 signals prescribed for intercepting aircraft.