Air Traffic Operation


Reduced Vertical Separation Minina

RVSM is the use of a 1,000Ft. separation minima between RVSM approved aircraft in airspace between FL290 and FL410 (inclusive). Traffic below FL290 will be separated by a 1,000Ft. separation minima and above FL410 by a 2,000Ft. separation minima. State aircraft are permitted to operate in RVSM airspace, even if the aircraft is not RVSM capable, subject to Controller workload. If approved to operate in RVSM airspace, a 2,000Ft. separation minima shall be applied between State aircraft and RVSM approved aircraft and other State aircraft.

Abbreviations and Definitions:
ACAS (TCAS) Airborne Collision Avoidance System
CVSM   Conventional Vertical Separation Minima
GAT   General Air Traffic (e.g. Civil Traffic)
GMU   GPS Monitoring Unit
HMU   Height Monitoring Unit
MASPS   Minimum Aircraft System Performance Specifications
MECMA   Middle East Central Monitoring Agency
OAT   Operational Air Traffic (e.g. Military Traffic)
 
Terms will be used with regard to RVSM airspace:
 

RVSM Entry Point – The first reporting point over which an aircraft passes or is expected to pass immediately before, upon or immediately after initial entry into RVSM Airspace from Non-RVSM Airspace, normally the first reference point for applying a 1,000Ft vertical separation minimum between RVSM approved aircraft.
RVSM Exit Point - The last reporting point over which an aircraft passes or is expected to pass immediately before, upon or immediately after leaving RVSM Airspace into Non-RVSM Airspace, normally the last reference point for applying a 1,000Ft vertical separation minimum between RVSM approved aircraft.
RVSM Airspace – that airspace between FL290 and FL 410 where a 1,000Ft vertical separation minima is applied between RVSM approved aircraft. This can be airspace within a certain FIR, portions of airspace within an FIR or airspace within a region.
State Aircraft – Only aircraft used in Military, Customs and Police services qualify as State Aircraft. (Royal Flight and other VIP aircraft are not regarded as State aircraft and cannot use RVSM airspace if the aircraft are not RVSM compliant.)

 

Cruising Levels Used in RVSM Airspace:

 

The following table shows the flight levels that are used in RVSM airspace.

RVSM Cruising Levels Appropriate to Direction of Flight (FL280 to FL430)

 
Track from 180deg to 359deg   Track from 360deg to 179deg
FL430   (Non RVSM Level)
    FL410
FL400    
    FL390
FL380    
    FL370
FL360    
    FL350
FL340    
    FL330
FL320    
    FL310
FL300    
    FL290

 

It should be noted that FL310, FL350 and FL390 become EASTBOUND levels in RVSM airspace.


Flight Planning:

All State aircraft i.e. Military, Customs or Police shall insert the letter “M” in Item 8 of the ICAO flight plan.

Operators of RVSM approved aircraft shall insert the letter ”W” in Item 10 of the ICAO flight plan.

Operators of non-RVSM approved State aircraft shall insert “STS/NONRVSM” in Item 18 of the ICAO flight plan.

Operators of formation flights of State aircraft shall NOT insert the letter ”W” in Item 10 of the ICAO flight plan, regardless of the RVSM approval status of the aircraft concerned. Operators of formation flights of State aircraft intending to operate within the MID RVSM airspace as GAT shall include “STS/NONRVSM” in Item 18 of the ICAO flight plan.

Operators of RVSM approved aircraft and non-RVSM approved State aircraft intending to operate within the MID RVSM airspace shall include the following in Item 15 of the ICAO flight plan:
The entry point and requested flight level into RVSM airspace: and
The exit point and requested flight level leaving RVSM airspace.
Note: there are no requirements to include entry/exit points between two adjacent RVSM areas e.g. MID and EUR (Middle East and Europe).

Non-RVSM approved civil aircraft are not permitted into RVSM airspace and shall flight plan to operate outside RVSM airspace i.e. by remaining at FL280 or below.

Operators of non-RVSM approved civil aircraft intending to operate from a departure aerodrome OUTSIDE RVSM airspace to a destination aerodrome WITHIN the lateral limits of RVSM airspace shall include the following in Item 15 of the ICAO flight plan:
The entry point into RVSM airspace; and
The requested flight level below FL290 for that portion of the route beginning immediately after the entry point into RVSM airspace.

Operators of non-RVSM approved civil aircraft intending to operate from a departure aerodrome WITHIN the lateral limits of RVSM airspace to a destination aerodrome OUTSIDE the lateral limits of RVSM airspace shall include the following in Item 15 of the ICAO flight plan:
A requested flight level below FL290 for that portion of the route within the lateral limits of RVSM airspace; and
The exit point from RVSM airspace and the requested flight level for that portion of the route beginning immediately after the exit point from RVSM airspace.

Operators of non-RVSM approved civil aircraft intending to operate from a departure aerodrome OUTSIDE the lateral limits of RVSM airspace to a destination aerodrome OUTSIDE the lateral limits of RVSM airspace but with part of the route within the lateral limits of RVSM airspace shall include the following in Item 15 of the ICAO flight plan:
The entry point into RVSM airspace and a requested flight level below FL290 or above FL410 for that portion of the route beginning immediately after the entry point into RVSM airspace; and
The exit point from RVSM airspace and the requested flight level for that portion of the route beginning immediately after the exit point from RVSM airspace.

ATC Clearances:

Only RVSM approved aircraft and non-RVSM approved State aircraft will be issued with an ATC clearance to operate in RVSM airspace. All other non-RVSM approved aircraft will have to plan to operate below FL290 to keep them out of RVSM airspace.

If the RVSM approval status of an aircraft is not known e.g. the information was not received on the flight plan, the Controller shall ask the pilot to confirm the RVSM status of the aircraft. If the pilot confirms “RVSM approved”, the Controller shall consider the flight as being RVSM approved. If the aircraft is proceeding into an adjacent FIR, this information shall be relayed to the accepting unit, either as part of the coordination message or as a separate coordination message.

Formation flights of civil traffic shall not be cleared into RVSM airspace, even if they are RVSM compliant.

Formation flights of State aircraft may be cleared into RVSM airspace. However, they shall be regarded as being non-RVSM compliant, regardless of the RVSM status of individual aircraft in the formation. As such, they shall request special handling by ATC and a minimum vertical separation minima of 2,000Ft. shall be provided between the formation flight and all other traffic operating in RVSM airspace.

Vertical Separation Minima:

The following vertical separation minima shall be used in RVSM airspace:

a

Between RVSM compliant aircraft

1000 ft

b

Between non RVSM approved State aircraft and any other aircraft

2000 ft

c

Between all formation flights of State aircraft and any other aircraft

2000 ft

d

Between an aircraft experiencing a communications failure and any other aircraft

2000 ft

e

Between an aircraft experiencing severe turbulence e.g. due to weather or wake vortex (turbulence) and other aircraft

2000 ft

The implementation of a 2,000Ft minima caused by reports of severe turbulence shall be coordinated with any adjacent Sector or Unit that may also be affected.

The use of all levels between FL290 and FL410 is approved for use in severe turbulence conditions and between non-RVSM approved State aircraft and RVSM approved aircraft e.g. one aircraft may be cleared to FL300 and to ensure the 2,000Ft separation, the next aircraft will be at FL320. In Controlled Airspace, flight levels can be used for East or West-bound traffic e.g. to ensure separation with a West-bound non-RVSM approved State aircraft at FL300 an East-bound RVSM approved aircraft can be cleared to FL320 until separation is achieved by other means e.g. lateral separation determined by radar.

The tolerance value used to determine that Mode C derived level information is accurate shall be 300 ft. or more. If the displayed level information is not within the approved tolerance value or when a difference greater than the approved tolerance value is detected after checking, the pilot shall be requested to check the pressure setting and confirm the aircraft’s level e.g. if the Mode C readout shows FL303 instead of FL300, the pilot shall be requested to verify his pressure settings and FL.

If a pilot informs ATC that his aircraft’s equipment no longer meets the RVSM criteria, the Controller will regard the aircraft as non-RVSM compliant and take action to immediately provide a vertical separation minima of 2,000Ft or appropriate radar separation between this aircraft and other aircraft operating in RVSM airspace. The Controller will clear the aircraft out of RVSM airspace as soon as is practicable.

If a pilot informs ATC that he has managed to restore the aircraft’s equipment back to RVSM capability, ATC can use this information to restore normal RVSM criteria to the flight i.e. clearance back into RVSM airspace and/or the use of RVSM vertical separation.

The first ACC or Sector that becomes aware of a change to an aircraft’s RVSM status shall coordinate this with the relevant adjacent ACC/Sector that the flight will enter.

Phraseologies:

The following standard phraseologies have been developed for use with RVSM. These are international standards and Controllers should try to follow them as closely as possible. Any extra words or even a reduction of words could change the meaning of the phrase and cause confusion.

SUBJECT

PHRASEOLOGY
 

For a Controller to find out the RVSM status of an aircraft

 

….(callsign) CONFIRM RVSM APPROVED

For a pilot to report non-RVSM approval status:

  1. on the initial call on any frequency within the MID RVSM airspace.

  2. in all requests for flight level changes in MID RVSM airspace, and

  3. in all read-backs to flight level clearances in MID RVSM airspace

Additionally, except for State aircraft, pilots shall include this phrase to read-back flight level clearances involving the transit between FL290 or FL410.

 

NEGATIVE RVSM
(Controllers shall also use this phrase in the readback after the first contact.)

For the pilot of a non-RVSM approved State aircraft.

 

NEGATIVE RVSM STATE AIRCRAFT

For a pilot to report RVSM approval status

 

AFFIRM RVSM

For a Controller to deny (refuse) entry into RVSM airspace

 

….callsign) UNABLE CLEARANCE INTO RVSM AIRSPACE MAINTAIN (OR DESCEND TO OR CLIMB TO) FL

For a pilot to report when severe turbulence affects the aircraft’s capability to maintain the height keeping requirements for RVSM

 

UNABLE RVSM DUE TURBULENCE

For a pilot to report that the aircraft’s equipment has degraded to below that required for flight within RVSM airspace

 

UNABLE RVSM DUE EQUIPMENT

For a pilot to report ready to resume operations within RVSM airspace after an equipment or weather related problem

 

READY TO RESUME RVSM

For a Controller to confirm that an aircraft has regained its RVSM approval status, or to confirm that the pilot is ready to resume RVSM operations

 

CONFIRM ABLE TO RESUME RVSM


COORDINATION BETWEEN ATS UNITS
 

To verbally supplement an automated estimate message exchange that does not automatically transfer Item 18 flight plan information

 

NEGATIVE RVSM OR NEGATIVE RVSM STATE AIRCRAFT (as applicable)

To verbally supplement estimate messages of non-RVSM approved aircraft

 

NEGATIVE RVSM OR NEGATIVE RVSM STATE AIRCRAFT (as applicable)

To coordinate the cause of a contingency relating to an aircraft that is unable to conduct RVSM operations due to severe turbulence or other severe weather related phenomenon (e.g. a line of thunder storms) or equipment failure as applicable

 

….(callsign) UNABLE RVSM DUE TURBULENCE (OR EQUIPMENT) as applicable

 

Coordination:

The standard coordination phraseology for coordination messages will be used. However, the following information shall be included at the end of the coordination message if applicable:

For non RVSM aircraft: “NEGATIVE RVSM”
For non RVSM State aircraft: “NEGATIVE RVSM STATE AIRCRAFT”

When a single aircraft is experiencing an in–flight contingency (problem) that affects its RVSM operations e.g. some of the aircraft’s RVSM equipment has failed or the flight is experiencing severe turbulence which affects its ability to maintain RVSM required FL accuracy, the following information shall be included at the end of the coordination message as applicable:

Equipment failure: “UNABLE RVSM DUE EQUIPMENT”
An aircraft is experiencing severe turbulence: “UNABLE RVSM DUE TURBULENCE”

The relevant sector Controller is responsible for ensuring that this information is given to the next sector or Unit.