ENR 1.8 REGIONAL SUPPLEMENTARY PROCEDURES

These supplementary procedures are taken from ICAO Doc 7030 – Supplementary Procedures – and relating to the MID-ASIA Region are given in their entirety. For differences applied in Oman, see GEN 1.7.

These procedures are supplementary to the provisions contained in ICAO Annex 2, Annex 6 (Part II), Annex 11, PANS-ATM (Doc 4444) and PANS-OPS (Doc 8168).

1. FLIGHT RULES

1.1 Visual Flight Rules (VFR)
(Relating to Annex 2 - 4.7 and 4.8)

1.1.1 Special Application

Oman requires VFR flights that operate at any aerodrome with Air Traffic Services shall have two-way radio communications (See ENR 1.2.3)

1.2 Instrument Flight Rules (IFR)
(Relating to Annex 2.2 and Chapter 5)

Note: Annex 2, 2.2 permits a choice for a flight to comply with either the instrument flight rules or the visual flight rules when operating in visual meteorological conditions subject to certain limitations in Chapter 4 of the Annex. The following indicates certain further restrictions to that choice.

1.2.1 Special Application of Instrument Flight Rules

1.2.1.1 Flights shall be conducted in accordance with the Instrument Flight Rules (even when not operating in instrument meteorological conditions) when operated:

1. more than 100 NM seaward from the shoreline within controlled airspace; or

2. above flight level 150.

2. FLIGHT PLANS

2.1 Content - General
(Relating to Annex 2 – Chapter 3; P-ATM – Chapter 4 and Appendix 2)

2.1.1 Reduced Vertical Separation Minimum (RVSM)- Approved Aircraft

2.1.1.1 The aircraft registration shall be inserted in Item 18 of the ICAO flight plan form.

2.1.1.2 Operators of formation flights of State aircraft shall not insert the letter W in Item 10 of the ICAO flight plan form, regardless of the RVSM approval status of the aircraft concerned. Operators of formation flights of State aircraft intending to operate within the RVSM airspace specified in 4.1 b) 2 shall include STS/NONRVSM in Item 18 of the ICAO flight plan form.

2.1.2 Non-RVSM - Approved Aircraft

2.1.2.1 Civil operators of non-RVSM-approved aircraft shall flight plan to operate outside the RVSM airspace specified in 4.1.

2.1.3 Mach Number

2.1.3.1 For turbo-jet aircraft intending to operate within airspace and on air routes to which longitudinal separation minima utilizing Mach number technique will be applied, the planned true Mach number shall be specified in Item 15 of the flight plan.

3. COMMUNICATIONS

3.1 Air-Ground Communications and In-Flight Reporting

3.1.1 Continuous listening watch in uncontrolled airspace (Relating to Annex 2 – Chapters 3 and 5; P-ATM – Chapter 4)

3.1.1.1 All VFR flights, and IFR flights outside controlled airspace, shall maintain a listening watch on the frequency where flight information service is provided and report position unless otherwise authorized by the State overflown.

4. REDUCED VERTICAL SEPARATION MINIMUM (RVSM)

4.1 Area of Applicability

RVSM shall be applicable in that volume of airspace between FL290 and FL410 inclusive in the Muscat FIR/ UIR, as described in ENR 2.1.

Within this airspace, the vertical separation minimum shall be:

a) 1000 FT between RVSM approved aircraft;

b) 2000 FT between:

1) non-RVSM approved State aircraft and any other aircraft operating within the RVSM airspace;

2) formation flights of State aircraft and any other aircraft operating within the RVSM airspace;

3) an aircraft experiencing a communication failure in flight and any other aircraft, when both aircraft are operating within RVSM airspace.

5. PHRASEOLOGY

(P-ATM – Chapter 12)

5.1 RNAV

5.1.1 The phrase “UNABLE RNAV DUE EQUIPMENT” shall be included by the pilot immediately following the aircraft call sign whenever initial contact on an ATC frequency is established by an aircraft experiencing a failure or degradation of the RNAV system.

5.1.2 The phrase “NEGATIVE RNAV” shall be included by the pilot immediately following the aircraft call sign whenever initial contact on an ATC frequency is established by a State aircraft not equipped with RNAV.

6. INTERNATIONAL GENERAL AVIATION (IGA)

(Relating to Annex 6, Part II – Chapter 6)

6.1 General aviation aircraft operating over designated areas, land or sea, where search and rescue operations would be difficult, should:

a) carry appropriate survival equipment; and

b) follow the routes or specified procedures if not equipped with two-way radio, except that under special circumstances, the appropriate authority may grant specific exemptions from this requirement.

7. WEATHER DEVIATION PROCEDURES IN THE MUSCAT FIR

7.1 General

Note: The following procedures are intended for deviations around adverse meteorological conditions.

7.1.1 When weather deviation is required, the pilot should initiate communications with ATC via voice. A rapid response may be obtained by stating “WEATHER DEVIATION REQUIRED” to indicate that priority is desired on the frequency and for ATC response.

7.1.2 When necessary, the pilot should initiate the communications using the urgency call “PAN PAN” (preferably spoken three times).

7.1.3 The pilot shall inform ATC when weather deviation is no longer required, or when a weather deviation has been completed and the aircraft has returned to its cleared route.

7.2 Actions to be taken when controller-pilot communications are established

7.2.1 The pilot should notify ATC and request clearance to deviate from track or ATS route, advising, when possible, the extent of the deviation requested. The flight crew will use whatever means are appropriate to communicate during a weather deviation.

Note: Pilots are advised to contact ATC as soon as possible with requests for clearance in order to provide adequate time for the request to be assessed and acted upon.

7.2.2 After communicating with ATC, the pilot should take the following actions:

a) comply with the ATC clearance issued; or

b) advise ATC of intentions and execute the procedures detailed in 7.3

7.3 Actions to be taken if a revised ATC Clearance cannot be obtained

7.3.1 If the aircraft is required to deviate from track or ATS route to avoid adverse meteorological conditions and prior clearance cannot be obtained, an ATC clearance shall be obtained at the earliest possible time. Until an ATC clearance is received, the pilot shall take the following actions:

a) if possible, deviate away from an organized track or ATS route system;

b) establish communications with and alert nearby aircraft by broadcasting, at suitable intervals: aircraft identification, flight level, position (including ATS route designator or the track code) and intentions, on the frequency in use and on 121.5 MHz (or, as a backup, on the inter-pilot air-to-air frequency 123.45 MHz);

c) watch for conflicting traffic both visually and by reference to ACAS (if equipped);

d) turn on all aircraft exterior lights (commensurate with appropriate operating limitations);

e) for deviations of less than 5.0 NM from the originally cleared track or ATS route, remain at a level assigned by ATC;

f) for deviations greater than, or equal to 5.0 NM from the originally cleared track or ATS route, when the aircraft is approximately 5.0 NM from track, initiate a level change in accordance with the following table:

Originally cleared track or ATS route centreline	Deviations greater than 5NM	Level change
EAST 000-179 MAG	LEFT RIGHT	DESCEND 300 FT CLIMB 300 FT
WEST 180-359 MAG	LEFT RIGHT	CLIMB 300 FT DESCEND 300 FT

g) if the pilot receives clearance to deviate from cleared track or ATS route for a specified distance and, subsequently, requests, but cannot obtain a clearance to deviate beyond that distance, the pilot should apply an altitude offset in accordance with the table above before deviating beyond the cleared distance;

h) when returning to track or ATS route, be at its assigned flight level when the aircraft is within approximately 5.0 NM of the centreline; and

i) if contact was not established prior to deviating, continue to attempt to contact ATC to obtain a clearance. If contact was established, continue to keep ATC advised of intentions and obtain essential traffic information.

Note: If, as a result of actions taken under the provisions of 2.6, the pilot determines that there is another aircraft at or near the same flight level with which a conflict may occur, then the pilot is expected to adjust the path of the aircraft, as necessary, to avoid conflict.

8. SPECIAL PROCEDURES FOR IN-FLIGHT CONTINGENCIES

8.1 General

The following general procedures apply to both subsonic and supersonic aircraft. Although all possible contingencies cannot be covered, they provide for cases of inability to maintain assigned level due to weather, aircraft performance, pressurization failure and problems associated with high-level supersonic flight. They are applicable primarily when rapid descent and/or turn-back or diversion to an alternate airport are required. The pilot's judgment shall determine the sequence of actions taken, taking into account specific circumstances.

If an aircraft is unable to continue flight in accordance with its ATC clearance, a revised clearance shall, whenever possible, be obtained prior to initiating any action, using a distress or urgency signal as appropriate.

If prior clearance cannot be obtained, an ATC clearance shall be obtained at the earliest possible time and, until a revised clearance is received, the pilot shall:

a) if possible deviate away from an organized track or route system before commencing descent;

b) establish communications with and alert nearby aircraft by broadcasting, at suitable intervals: aircraft identification, flight level, aircraft position (including the ATS route designator or the track code) and intentions, on the frequency in use, as well as on frequency 121.50 MHz (or, as a back-up, the VHF inter-pilot air-to-air frequency 123.450 MHz);

c) watch for conflicting traffic both visually and by reference to ACAS (if equipped);

d) turn on all aircraft exterior lights; (commensurate with appropriate operating limitations);

e) advise the appropriate air traffic control unit as soon as possible of the emergency descent;

f) set the transponder to Code 7700 and select emergency mode on automatic dependent surveillance/ controller-pilot data link communications (ADS/ CPDLC) system, if applicable; and

g) coordinate further intentions with the appropriate ATC unit.

The aircraft shall not descend below the lowest published minimum altitude which will provide a minimum vertical clearance of 300 M (1000 FT) or in designated mountainous terrain 600 M (2000 FT) above all obstacles located in the area specified.

9. ACTION BY THE AIR TRAFFIC CONTROL UNIT

Immediately upon recognizing that an emergency descent is in progress, ATC units shall acknowledge the emergency on radiotelephony (RTF) and take all necessary action to safeguard all aircraft concerned.

In particular, they may, as required by the situation:

a) suggest a heading to be flown, if able, by the aircraft carrying out the emergency descent in order to achieve spacing from other aircraft concerned.

b) state the minimum altitude for the area of operation, only if the level-off altitude stated by the pilot is below such minimum altitude, together with the applicable QNH altimeter setting.

c) as soon as possible, provide separation with conflicting traffic, or issue essential traffic information, as appropriate.

When deemed necessary, air traffic control will broadcast an emergency message, or cause such message to be broadcast, to other aircraft concerned to warn them of the emergency descent.

10. SPECIAL PROCEDURES FOR SUBSONIC AIRCRAFT REQUIRING RAPID DESCENT AND/OR TURN-BACK OR DIVERSION TO AN ALTERNATE AIRPORT DUE TO AIRCRAFT SYSTEM MALFUNCTION OR OTHER CONTINGENCIES

Note: Additional procedures for in-flight contingencies involving a loss of vertical navigation performance required for flights within the RVSM airspace are contained in 11.

10.1 Initial Action

If unable to comply with the provision of 8.1 to obtain a revised ATC clearance, the aircraft should leave its assigned route or track by turning 90 degrees to the right or left whenever this is possible, The direction of the turn should, where possible, be determined by the position of the aircraft relative to any organized route or track system, e.g. whether the aircraft is outside, at the edge of, or within the system. Other factors to consider are the direction of the alternate airport, terrain clearance and the levels allocated to adjacent routes or tracks.

10.2 Subsequent Action (RVSM Airspace)

In RVSM airspace, an aircraft able to maintain its assigned flight level should turn to acquire and maintain in either direction a track laterally separated by 46 KM (25 NM) from its assigned route or track in a multi-track system spaced at 93 KM (50 NM) or otherwise, at a distance which is the mid-point from the adjacent parallel route or track; and

a) if above FL410, climb or descend 300 M (1000 FT); or

b) if below FL410, climb or descend 150 M (500 FT); or

c) if at FL410, climb 300 M (1000 FT) or descend 150 M (500 FT).

An aircraft that is unable to maintain its assigned flight level should:

a) initially minimize its rate of descent to the extent that is operationally feasible;

b) turn while descending to acquire and maintain in either direction a track laterally separated by 46 KM (25 NM) from its assigned route or track in a multitrack system spaced 93 KM (50 NM) or otherwise, at a distance which is the mid-point from the adjacent parallel route or track; and

c) for the subsequent level flight, select a level which differs from those normally used by 300 M (1000 FT) if above FL410, or by 150 M (500 FT) if below FL410.

11. DIVERSION ACROSS THE FLOW OF ADJACENT TRAFFIC

11.1 Before diverting across the flow of adjacent traffic, the aircraft should: climb above FL410 or descend below FL280 using the procedures specified in 10.1 or 10.2. However, if the pilot is unable or unwilling to carry out a major climb or descent, the aircraft should be flown at a level as defined in 10.2 or until a revised ATC clearance is obtained.

11.2 Extended range operations by aeroplanes with two turbine power-units (ETOPS) aircraft.

If these contingency procedures are employed by a twin-engine aircraft as a result of an engine shutdown or failure of an ETOPS critical system, the pilot should advise ATC as soon as practicable of the situation, reminding ATC of the type of aircraft involved, and request expeditious handling.

11.3 Special procedures for in-flight contingencies involving a loss of vertical navigation performance.

a) Degradation of aircraft equipment - pilot reported

1) When informed by the pilot of an RVSM approved aircraft operating in the RVSM airspace that the aircraft's equipment no longer meets the RVSM MASPS, ATC shall consider the aircraft as non-RVSM approved.

2) ATC shall take action immediately to provide a minimum vertical separation of 600 M (2000 FT) or an appropriate horizontal separation from all other aircraft concerned that are operating in the RVSM airspace. An aircraft rendered non-RVSM approved shall normally be cleared out of the RVSM airspace by ATC when it is possible to do so.

3) Pilots shall inform ATC, as soon as practicable, of any restoration of the proper functioning of equipment required to meet the RVSM MASPS.

b) Severe turbulence - not forecast

1) When an aircraft operating in the RVSM airspace encounters severe turbulence due to weather or wake vortex that the pilot believes will impact the aircraft's capability to maintain its cleared flight level, the pilot shall inform ATC.

11.4 Weather deviation procedures for oceanic-controlled airspace

a) General

1) The following procedures are intended to provide guidance. All possible circumstances cannot be covered. The pilot's judgment shall ultimately determine the sequence of actions taken, and ATC shall render all possible assistance.

2) If the aircraft is required to deviate from track to avoid weather and prior clearance cannot be obtained, an ATC clearance shall be obtained at the earliest possible time. Until an ATC clearance is received, the aircraft shall follow the procedures detailed in 11.4 d) below.

3) The pilot shall advise ATC when weather deviation is no longer required, or when a weather deviation has been completed and the aircraft has returned to the centre line of its cleared route.

b) Obtaining priority from ATC when weather deviation is required:

1) When the pilot initiates communications with ATC, rapid response may be obtained by stating "WEATHER DEVIATION REQUIRED" to indicate that priority is desired on the frequency and for ATC response.

2) The pilot still retains the option of initiating the communications using the urgency call "PAN PAN" (preferably spoken three times) to alert all listening parties to a special handling condition which will receive ATC priority for issuance of a clearance or assistance.

c) Actions to be taken when controller-pilot communications are established.

1) Pilot notifies ATC and requests clearance to deviate from track. advising, when possible, the extent of the deviation expected.

2) ATC takes one of the following actions:

a) if there is no conflicting traffic in the horizontal dimension, ATC will issue clearance to deviate from track; or

b) if there is conflicting traffic in the horizontal dimension, ATC separates aircraft by establishing vertical separation; or

c) if there is conflicting traffic in the horizontal dimension and ATC is unable to establish appropriate separation, ATC shall:

- advise the pilot of inability to issue clearance for requested deviation; and

- advise pilot of conflicting traffic; and

- request pilot’s intentions.

SAMPLE PHRASEOLOGY

UNABLE (request deviation), TRAFFIC IS (call sign, position, altitude, direction) ADVISE INTENTIONS

3) Pilot will take following actions:

a) advise ATC of intentions by the most expeditious means available; and

b) comply with air traffic control clearance issued; or

c) execute the procedures detailed in 11.4 d) below (ATC will issue essential traffic information to all affected aircraft); and

d) if necessary, establish voice communications with ATC to expedite dialogue on the situation.

d) Actions to be taken if a revised ATC clearance cannot be obtained.

1) The provisions of this section apply to situations where the pilot has the need to exercise the authority of a pilot-in-command under the provisions of Annex 2, 2.3.1

2) If a revised ATC clearance cannot be obtained and deviation from track is required to avoid weather, the pilot shall take the following actions:

a) if possible, deviate away from an organized track or route system;

b) establish communication with and alert nearby aircraft by broadcasting at suitable intervals: aircraft identification, flight level, aircraft position (including the ATS route designator or the track code) and intentions (including the magnitude of the deviation expected) on the frequency in use, as well as on frequency 121.50 MHz (or as a backup the VHF inter-pilot air-to-air frequency 123.450 MHz);

c) watch for conflicting traffic both visually and by reference to ACAS (if equipped);

Note If as a result of action taken under 11.4 d) 2) b) and c) above, the pilot determines that there is another aircraft at or near the same flight level with which a conflict may occur, then the pilot is expected to adjust the path of the aircraft, as necessary, to avoid conflict.

d) turn on aircraft exterior lights (commensurate with appropriate operating limitations);

e) for deviations less than 19 KM (10 NM) aircraft should remain at a level assigned by ATC;

f) for deviations of greater than 19 KM (10 NM), when the aircraft is approximately 19 KM (10 NM) from track, initiate a level change based on the critical in Table below;

g) when returning to track, be at its assigned level, when the aircraft is within approximately 19 KM (10 NM) of centre line; and

h) if contact was not established prior to deviating, continue to attempt to contact ATC to obtain a clearance. If contact was established, continue to keep ATC advised of intentions and obtain essential traffic information.

12. WAKE TURBULENCE PROCEDURES

12.1 The following special procedures are applicable to mitigate wake turbulence encounters in airspace where RVSM is applied.

a) An aircraft that encounters wake turbulence should notify (ATC) and request a revised clearance. However, in situations where a revised clearance is not possible or practicable:

1) the pilot should establish contact with other aircraft, if possible, on the appropriate VHF interpilot air-to-air frequency; and

2) one (or both) aircraft may initiate lateral offset(s) not to exceed 2 NM from the assigned route(s) or track(s), provided that:

a) as soon as it is practicable to do so, the offsetting aircraft notify ATC that temporary lateral offset has been taken and specify the reason for doing so; and

b) the offsetting aircraft notify ATC when reestablished on assigned route(s) or track(s).

Note: In the contingency circumstances above, ATC will not issue clearances for lateral offsets and will not normally respond to action taken by pilots.

Route centre line track	Deviations > 19 KM (10 NM)	Level change
EAST 000-179 MAG	LEFT RIGHT	DESCEND 90 M (300 FT) CLIMB 90 M (300 FT)
WEST 180-359 MAG	LEFT RIGHT	CLIMB 90 M (300 FT) DESCEND 90 M (300 FT)

12.2 Wake Turbulence Categories

With the purpose to preserve safety and to limit the effects of the separation prescriptions on airports capacity, air traffic control applies the following categories to separate aircraft in the approach and departure phases of flight:

Category	MTOM in KG
LIGHT L	7000 KG or less
MEDIUM M	more than 7 000 KG and less than 136 000 KG
HEAVY H	136 000 KG and more

12.3 Separation Criteria

For wake turbulence separation purposes, two parallel runways less than 760 M apart, or a helipad less than 760 M from a runway, will be considered as one runway.

The appropriate wake turbulence radar separation, as shown in the table below, are applied between aircraft in the approach and departure phases of flight, when:

a) an aircraft is operating directly behind another aircraft at the same altitude or less than 1000 FT below; or

b) an aircraft is crossing behind another aircraft at the same altitude or less than 1000 FT below; or both

c) are using the same runway, or parallel runways separated by less than 760 M.

	Lead
Follow	HEAVY	MEDIUM	SMALL	LIGHT
HEAVY	4 NM	N/A	N/A	N/A
MEDIUM	5 NM	N/A	N/A	N/A
LIGHT	6 NM	5 NM	N/A	N/A

Aircraft carrying out missed approaches or low goarounds are considered as a departure relating to separation. In case of a missed approach procedure or a low go-around in the opposite direction of the succeeding departure, a separation of 2 minutes is applied between an aircraft of category M or L and an overflying aircraft of category H.

WAKE VORTEX ENCOUNTER REPORTING FORM