Separation Standards

Introduction:

  • Separation standards are the processes, procedures and rules in place by Air Traffic Control to improve safety in the National Airspace System (NAS)

Instrument Flight Rules Separation Standards:

  • Standard IFR separation is provided to all aircraft operating under IFR in controlled airspace
  • ATC effects separation of aircraft vertically by assigning different altitudes; longitudinally by providing an interval expressed in time or distance between aircraft on the same, converging, or crossing courses, and laterally by assigning different flight paths
  • Separation will be provided between all aircraft operating on IFR flight plans except during that part of the flight (outside Class B airspace or a TRSA) being conducted on a VFR-on-top/VFR conditions clearance
    • Under these conditions ATC may issue traffic advisories, but it is the sole responsibility of the pilot to be vigilant so as to see and avoid other aircraft
  • When radar is employed in the separation of aircraft at the same altitude, a minimum of 3 miles separation is provided between aircraft operating within 40 miles of the radar antenna site, and 5 miles between aircraft operating beyond 40 miles from the antenna site
    • Certain separation standards may be increased in the terminal environment due to radar outages or other technical reasons

Wake Turbulence Separation:

  • Because of the possible effects of wake turbulence, controllers are required to apply no less than minimum required separation to all aircraft operating behind a Super or Heavy, and to Small aircraft operating behind a B757, when aircraft are IFR; VFR and receiving Class B, Class C, or TRSA airspace services; or VFR and being radar sequenced
    • Separation is applied to aircraft operating directly behind a super or heavy at the same altitude or less than 1,000 feet below, and to small aircraft operating directly behind a B757 at the same altitude or less than 500 feet below:
      • Heavy behind super - 6 miles
      • Large behind super - 7 miles
      • Small behind super - 8 miles
      • Heavy behind heavy - 4 miles
      • Small/large behind heavy - 5 miles
      • Small behind B757 - 4 miles
    • Also, separation, measured at the time the preceding aircraft is over the landing threshold, is provided to small aircraft:
      • Small landing behind heavy - 6 miles
      • Small landing behind large, non-B757 - 4 miles
    • Note that these terms are found in the Pilot/Controller Glossary Term - Aircraft Classes
  • Additionally, appropriate time or distance intervals are provided to departing aircraft when the departure will be from the same threshold, a parallel runway separated by less than 2,500 feet with less than 500 feet threshold stagger, or on a crossing runway and projected flight paths will cross:
    • Three minutes or the appropriate radar separation when takeoff will be behind a super aircraft;
    • Two minutes or the appropriate radar separation when takeoff will be behind a heavy aircraft
    • Two minutes or the appropriate radar separation when a small aircraft will takeoff behind a B757
    • NOTE: Controllers may not reduce or waive these intervals
  • A 3-minute interval will be provided when a small aircraft will takeoff:
    • From an intersection on the same runway (same or opposite direction) behind a departing B757, or
    • In the opposite direction on the same runway behind a B757 takeoff or low/missed approach
      • NOTE: This 3-minute interval may not be waived upon specific pilot request
  • A 4-minute interval will be provided for all aircraft taking off behind a super aircraft, and a 3-minute interval will be provided for all aircraft taking off behind a heavy aircraft when the operations are as described in subparagraphs b1 and b2 above, and are conducted on either the same runway or parallel runways separated by less than 2,500 feet. Controllers may not reduce or waive this interval
  • Pilots may request additional separation (i.e., 2 minutes instead of 4 or 5 miles) for wake turbulence avoidance. This request should be made as soon as practical on ground control and at least before taxiing onto the runway
  • NOTE: 14 CFR Section 91.3(a) states: "The pilot-in-command of an aircraft is directly responsible for and is the final authority as to the operation of that aircraft"
  • Controllers may anticipate separation and need not withhold a takeoff clearance for an aircraft departing behind a large, heavy, or super aircraft if there is reasonable assurance the required separation will exist when the departing aircraft starts takeoff roll
  • With the advent of new wake turbulence separation methodologies known as Wake Turbulence Recategorization, some of the requirements listed above may vary at facilities authorized to operate in accordance with Wake Turbulence Recategorization directives
  • Note that ultimately, when operating under VFR, it is up to the pilot, and not ATC, to provide this separation

Speed Adjustments:

  • ATC will issue speed adjustments to pilots of radar-controlled aircraft to achieve or maintain appropriate spacing
    • If necessary, ATC will assign a speed when approving deviations or radar vectoring off procedures that include published speed restrictions
    • If no speed is assigned, speed becomes pilot's discretion
    • However, when the aircraft reaches the end of the STAR, the last published speed on the STAR must be maintained until ATC deletes it, assigns a new speed, issues a vector, assigns a direct route, or issues an approach clearance
  • ATC will express all speed adjustments in terms of knots based on indicated airspeed (IAS) in 5 or 10 knot increments except that at or above FL 240 speeds may be expressed in terms of Mach numbers in 0.01 increments
    • The use of Mach numbers is restricted to turbojet aircraft with Mach meters
  • Pilots complying with speed adjustments (published or assigned) are expected to maintain within ± 10 knots/0.02 Mach number or 5% of the specified speed in accordance with reporting requirements
  • When ATC assigns speed adjustments, it will be in accordance with the following recommended minimums:
    • To aircraft operating between FL 280 and 10,000 feet, a speed not less than 250 knots or the equivalent Mach number
      • On a standard day the Mach numbers equivalent to 250 knots CAS (subject to minor variations) are:
        • FL 240-0.6
        • FL 250-0.61
        • FL 260-0.62
        • FL 270-0.64
        • FL 280-0.65
        • FL 290-0.66
      • When an operational advantage will be realized, speeds lower than the recommended minima may be applied
      • s
    • To arriving turbojet aircraft operating below 10,000 feet:
      • A speed not less than 210 knots, except;
      • Within 20 flying miles of the airport of intended landing, a speed not less than 170 knots
    • To arriving reciprocating engine or turboprop aircraft within 20 flying miles of the runway threshold of the airport of intended landing, a speed not less than 150 knots
    • To departing aircraft:
      • Turbojet aircraft, a speed not less than 230 knots
      • Reciprocating engine aircraft, a speed not less than 150 knots
  • When ATC combines a speed adjustment with a descent clearance, the sequence of delivery, with the word "then" between, indicates the expected order of execution
    • ATC: "Descend and maintain [altitude]; then, reduce speed to [speed]"
    • ATC: "Reduce speed to [speed]; then, descend and maintain [altitude]"
  • The maximum speeds below 10,000 feet as established in 14 CFR Section 91.117 still apply
    • If there is any doubt concerning the manner in which such a clearance is to be executed, request clarification from ATC
  • If ATC determines (before an approach clearance is issued) that it is no longer necessary to apply speed adjustment procedures, they will:
    • Advise the pilot to "resume normal speed"
      • Normal speed is used to terminate ATC assigned speed adjustments on segments where no published speed restrictions apply
      • It does not cancel published restrictions on upcoming procedures
      • This does not relieve the pilot of those speed restrictions which are applicable to 14 CFR Section 91.117
        • Example: (An aircraft is flying a SID with no published speed restrictions. ATC issues a speed adjustment and instructs the aircraft where the adjustment ends): "Maintain two two zero knots until BALTR then resume normal speed"
        • The ATC assigned speed assignment of two two zero knots would apply until BALTR. The aircraft would then resume a normal operating speed while remaining in compliance with 14 CFR Section 91.117
    • Instruct pilots to "comply with speed restrictions" when the aircraft is joining or resuming a charted procedure or route with published speed restrictions
      • Example: (ATC vectors an aircraft off of a SID to rejoin the procedure at a subsequent waypoint. When instructing the aircraft to resume the procedure, ATC also wants the aircraft to comply with the published procedure speed restrictions): "Resume the SALTY ONE departure. Comply with speed restrictions"
      • Caution: The phraseology "Descend via/Climb via SID" requires compliance with all altitude and/or speed restrictions depicted on the procedure
    • Instruct the pilot to "resume published speed"
      • Resume published speed is issued to terminate a speed adjustment where speed restrictions are published on a charted procedure
        • When instructed to "comply with speed restrictions" or to "resume published speed," ATC anticipates pilots will begin adjusting speed the minimum distance necessary prior to a published speed restriction so as to cross the waypoint/fix at the published speed. Once at the published speed, ATC expects pilots will maintain the published speed until additional adjustment is required to comply with further published or ATC assigned speed restrictions or as required to ensure compliance with 14 CFR Section 91.117
        • EXAMPLE: (An aircraft is flying a SID/STAR with published speed restrictions. ATC issues a speed adjustment and instructs the aircraft where the adjustment ends): "Maintain two two zero knots until BALTR then resume published speed"
        • NOTE: The ATC assigned speed assignment of two two zero knots would apply until BALTR. The aircraft would then comply with the published speed restrictions
    • Advise the pilot to "delete speed restrictions" when either ATC assigned or published speed restrictions on a charted procedure are no longer required
      • EXAMPLE: (An aircraft is flying a SID with published speed restrictions designed to prevent aircraft overtake on departure. ATC determines there is no conflicting traffic and deletes the speed restriction): "Delete speed restrictions"
      • NOTE: When deleting published restrictions, ATC must ensure obstacle clearance until aircraft are established on a route where no published restrictions apply. This does not relieve the pilot of those speed restrictions which are applicable to 14 CFR Section 91.117
  • Instruct the pilot to "climb via" or "descend via"
    • A climb via or descend via clearance cancels any previously issued speed restrictions and, once established on the depicted departure or arrival, to climb or descend, and to meet all published or assigned altitude and/or speed restrictions
    • EXAMPLE:
      • (An aircraft is flying a SID with published speed restrictions. ATC has issued a speed restriction of 250 knots for spacing. ATC determines that spacing between aircraft is adequate and desires the aircraft to comply with published restrictions): "United 436, Climb via SID"
      • (An aircraft is established on a STAR. ATC must slow an aircraft for the purposes of spacing and assigns it a speed of 280 knots. When spacing is adequate, ATC deletes the speed restriction and desires that the aircraft comply with all published restrictions on the STAR): "Gulfstream two three papa echo, descend via the TYLER One arrival"
    • NOTE:
      • In example 1, when ATC issues a "Climb via SID" clearance, it deletes any previously issued speed and/or altitude restrictions. The pilot should then vertically navigate to comply with all speed and/or altitude restrictions published on the SID
      • In example 2, when ATC issues a "Descend via arrival," ATC has canceled any previously issued speed and/or altitude restrictions. The pilot should vertically navigate to comply with all speed and/or altitude restrictions published on the STAR
    • CAUTION:
      • When descending on a STAR, pilots should not speed up excessively beyond the previously issued speed. Otherwise, adequate spacing between aircraft descending on the STAR that was established by ATC with the previous restriction may be lost
  • Approach clearances supersede any prior speed adjustment assignments, and pilots are expected to make their own speed adjustments as necessary to complete the approach. However, under certain circumstances, it may be necessary for ATC to issue further speed adjustments after approach clearance is issued to maintain separation between successive arrivals. Under such circumstances, previously issued speed adjustments will be restated if that speed is to be maintained or additional speed adjustments are requested. Speed adjustments should not be assigned inside the final approach fix on final or a point 5 miles from the runway, whichever is closer to the runway
  • The pilots retain the prerogative of rejecting the application of speed adjustment by ATC if the minimum safe airspeed for any particular operation is greater than the speed adjustment
    • NOTE: In such cases, pilots are expected to advise ATC of the speed that will be used
  • Pilots are reminded that they are responsible for rejecting the application of speed adjustment by ATC if, in their opinion, it will cause them to exceed the maximum indicated airspeed prescribed by 14 CFR Section 91.117(a), (c) and (d). IN SUCH CASES, THE PILOT IS EXPECTED TO SO INFORM ATC. Pilots operating at or above 10,000 feet MSL who are issued speed adjustments which exceed 250 knots IAS and are subsequently cleared below 10,000 feet MSL are expected to comply with 14 CFR Section 91.117(a)
  • Speed restrictions of 250 knots do not apply to U.S. registered aircraft operating beyond 12 nautical miles from the coastline within the U.S. Flight Information Region, in Class E airspace below 10,000 feet MSL. However, in airspace underlying a Class B airspace area designated for an airport, or in a VFR corridor designated through such as a Class B airspace area, pilots are expected to comply with the 200 knot speed limit specified in 14 CFR Section 91.117(c)
  • For operations in a Class C and Class D surface area, ATC is authorized to request or approve a speed greater than the maximum indicated airspeeds prescribed for operation within that airspace (14 CFR Section 91.117(b))
    • NOTE: Pilots are expected to comply with the maximum speed of 200 knots when operating beneath Class B airspace or in a Class B VFR corridor (14 CFR Section 91.117(c) and (d))
  • When in communications with the ARTCC or approach control facility, pilots should, as a good operating practice, state any ATC assigned speed restriction on initial radio contact associated with an ATC communications frequency change
  • Pilot:

    • Advises ATC any time cruising airspeed varies plus or minus 5 percent or 10 knots, whichever is greater, from that given in the flight plan
    • Complies with speed adjustments from ATC unless:
      • The minimum or maximum safe airspeed for any particular operation is greater or less than the requested airspeed. In such cases, advises ATC
        • It is the pilot's responsibility and prerogative to refuse speed adjustments considered excessive or contrary to the aircraft's operating specifications
      • Operating at or above 10,000 feet MSL on an ATC assigned SPEED ADJUSTMENT of more than 250 knots IAS and subsequent clearance is received for descent below 10,000 feet MSL. In such cases, pilots are expected to comply with 14 CFR Section 91.117(a)
    • When complying with speed adjustment assignments, maintains an indicated airspeed within plus or minus 10 knots or 0.02 Mach number of the specified speed
  • Controller:

    • Assigns speed adjustments to aircraft when necessary but not as a substitute for good vectoring technique
    • Adheres to the restrictions published in the FAAO JO 7110.65, Air Traffic Control, as to when speed adjustment procedures may be applied
    • Avoids speed adjustments requiring alternate decreases and increases
    • Assigns speed adjustments to a specified IAS (KNOTS)/Mach number or to increase or decrease speed using increments of 5 knots or multiples thereof
    • Terminates ATC-assigned speed adjustments when no longer required by issuing further instructions to pilots in the following manner:
      • Advises pilots to "resume normal speed" when the aircraft is on a heading, random routing, charted procedure, or route without published speed restrictions
      • Instructs pilots to "comply with speed restrictions" when the aircraft is joining or resuming a charted procedure or route with published speed restrictions
        • The phraseology "comply with restrictions" requires compliance with all altitude and/or speed restrictions depicted on the procedure
      • Instructs pilots to "resume published speed" when aircraft are cleared via a charted instrument flight procedure that contains published speed restrictions
      • Advises aircraft to "delete speed restrictions" when ATC assigned or published speed restrictions on a charted procedure are no longer required
      • Clears pilots for approach without restating previously issued speed adjustments
    • Gives due consideration to aircraft capabilities to reduce speed while descending
    • Does not assign speed adjustments to aircraft at or above FL 390 without pilot consent

Runway Separation:

  • Tower controllers establish the sequence of arriving and departing aircraft by requiring them to adjust flight or ground operation as necessary to achieve proper spacing. They may "HOLD" an aircraft short of the runway to achieve spacing between it and an arriving aircraft; the controller may instruct a pilot to "EXTEND DOWNWIND" in order to establish spacing from an arriving or departing aircraft. At times a clearance may include the word "IMMEDIATE"
    • For example: "CLEARED FOR IMMEDIATE TAKEOFF." In such cases "IMMEDIATE" is used for purposes of air traffic separation. It is up to the pilot to refuse the clearance if, in the pilot's opinion, compliance would adversely affect the operation

Gate Holding Due to Departure Delays:

  • Pilots should contact ground control or clearance delivery prior to starting engines as gate hold procedures will be in effect whenever departure delays exceed or are anticipated to exceed 15 minutes
    • The sequence for departure will be maintained in accordance with initial call up unless modified by flow control restrictions
    • Pilots should monitor the ground control or clearance delivery frequency for engine startup advisories or new proposed start time if the delay changes
  • The tower controller will consider that pilots of turbine-powered aircraft are ready for takeoff when they reach the runway or warm-up block unless advised otherwise

Runway:

  • Tower controllers establish the sequence of arriving and departing aircraft by requiring them to adjust flight or ground operation as necessary to achieve proper spacing
  • The may "hold" an aircraft short of the runway to achieve spacing between it and an arriving aircraft; the controller may instruct a pilot to "extend downwind" in order to establish spacing from an arriving or departing aircraft
  • At times a clearance may include the word "immediate"
    • For example: "cleared for immediate takeoff"
    • In such cases "immediate is used for the purposes of air traffic separation
  • It is up to the pilot to refuse the clearance if, in the pilots opinion, compliance would adversely affect operation

Visual Separation:

  • Visual separation is a means employed by ATC to separate aircraft in terminal areas and en route airspace in the NAS. There are two methods employed to effect this separation:
    • The tower controller sees the aircraft involved and issues instructions, as necessary, to ensure that the aircraft avoid each other
    • A pilot sees the other aircraft involved and upon instructions from the controller provides separation by maneuvering the aircraft to avoid it. When pilots accept responsibility to maintain visual separation, they must maintain constant visual surveillance and not pass the other aircraft until it is no longer a factor
    • Traffic is no longer a factor when during approach phase the other aircraft is in the landing phase of flight or executes a missed approach; and during departure or en route, when the other aircraft turns away or is on a diverging course
  • A pilot's acceptance of instructions to follow another aircraft or provide visual separation from it is an acknowledgment that the pilot will maneuver the aircraft as necessary to avoid the other aircraft or to maintain in-trail separation. In operations conducted behind heavy aircraft, or a small aircraft behind a B757 or other large aircraft, it is also an acknowledgment that the pilot accepts the responsibility for wake turbulence separation. Visual separation is prohibited behind super aircraft
    • When a pilot has been told to follow another aircraft or to provide visual separation from it, the pilot should promptly notify the controller if visual contact with the other aircraft is lost or cannot be maintained or if the pilot cannot accept the responsibility for the separation for any reason
  • Scanning the sky for other aircraft is a key factor in collision avoidance. Pilots and copilots (or the right seat passenger) should continuously scan to cover all areas of the sky visible from the cockpit. Pilots must develop an effective scanning technique which maximizes one's visual capabilities. Spotting a potential collision threat increases directly as more time is spent looking outside the aircraft. One must use timesharing techniques to effectively scan the surrounding airspace while monitoring instruments as well
  • Since the eye can focus only on a narrow viewing area, effective scanning is accomplished with a series of short, regularly spaced eye movements that bring successive areas of the sky into the central visual field. Each movement should not exceed ten degrees, and each area should be observed for at least one second to enable collision detection. Although many pilots seem to prefer the method of horizontal back-and-forth scanning every pilot should develop a scanning pattern that is not only comfortable but assures optimum effectiveness. Pilots should remember, however, that they have a regulatory responsibility (14 CFR Section 91.113(a)) to see and avoid other aircraft when weather conditions permit

Separation Responsibilities:

  • Pilot Responsibilities:

    • A pilot's acceptance of instructions to follow another aircraft or provide visual separation from it is an acknowledgment that the pilot will maneuver the aircraft as necessary to avoid the other aircraft or to maintain in-trail separation
      • Pilots are responsible to maintain visual separation until flight paths (altitudes and/or courses) diverge
      • In operations conducted behind heavy jet aircraft, it is also an acknowledgment that the pilot accepts the responsibility for wake turbulence separation
    • NOTE: When a pilot has been told to follow another aircraft or to provide visual separation from it, the pilot should promptly notify the controller if visual contact with the other aircraft is lost or cannot be maintained or if the pilot cannot accept the responsibility for the separation for any reason
    • Pilots and copilots (or the right seat passenger) should continuously scan to cover all areas of the sky visible from the cockpit
      • Pilots must develop an effective scanning technique which maximizes one's visual capabilities
      • Spotting a potential collision threat increases directly as more time is spent looking outside the aircraft
      • One must use timesharing techniques to effectively scan the surrounding airspace while monitoring instruments as well
    • Since the eye can focus only on a narrow viewing area, effective scanning is accomplished with a series of short, regularly spaced eye movements that bring successive areas of the sky into the central visual field. Each movement should not exceed ten degrees, and each area should be observed for at least one second to enable collision detection. Although many pilots seem to prefer the method of horizontal back-and-forth scanning every pilot should develop a scanning pattern that is not only comfortable but assures optimum effectiveness. Pilots should remember, however, that they have a regulatory responsibility (14 CFR Section 91.113(a)) to see and avoid other aircraft when weather conditions permit
  • Controller Responsibilities:

    • With regard to visual separation:
      • Within the terminal area when a controller has both aircraft in sight or by instructing a pilot who sees the other aircraft to maintain visual separation from it
      • Pilots are responsible to maintain visual separation until flight paths (altitudes and/or courses) diverge
      • Within en route airspace when aircraft are on opposite courses and one pilot reports having seen the other aircraft and that the aircraft have passed each other

Reduced Vertical Separation Minimum (RVSM):

  • Reduced Vertical Separation Minimum (RVSM) were established to accommodate the increase in traffic while maintaining a high level of safety
  • Changing the separation above flight level (FL) 290 from 2,000' to 1,000' minimum adds 6 more flight levels while increases in equipment reliability maintains public safety
  • Reduced Vertical Separation Minimum (RVSM) was required by the FAA to allow for the heavy flow of traffic
  • In addition to reorganizing airspace, it requires operators and aircraft to have received RVSM authorization from a responsible civil aviation authority
  • Instrument Flying Handbook. Figure 3-9, Increase in Aircraft Permitted Between FL 180 and FL 410
    Instrument Flying Handbook, Increase in Aircraft Permitted Between FL 180 and FL 410
  • RVSM Applicability:

    • RVSM applies to airspace over the lower 48 states, Alaska, Atlantic, and Gulf of Mexico High Offshore Airspace and airspace in the San Juan FIR where VHF or UHF voice Direct Controller-Pilot Communication (DCPC) is normally available
      • A chart showing the location of offshore airspace is posted on the Domestic U.S. RVSM (DRVSM) Webpage
    • Policies, guidance and direction for RVSM operations in oceanic airspace where VHF or UHF voice DCPC is not available and the airspace of other countries can be found in the Aeronautical Information Publication (AIP), Part II-En Route, ENR 1. General Rules and Procedures, and ENR 7. Oceanic Operations and as described below
  • RVSM Requirement:

    • The FAA implemented RVSM between flight level (FL) 290-410 (inclusive) in the following airspace:
      • The airspace of the lower 48 states of the United States, Alaska, Atlantic and Gulf of Mexico High Offshore Airspace and the San Juan FIR
      • RVSM has been implemented worldwide and may be applied in all ICAO Flight Information Regions (FIR)
  • RVSM Authorization:

    • In accordance with FAR 91.180, with only limited exceptions, prior to operating in RVSM airspace, operators must comply with the standards of Part 91, Appendix G, and be authorized by the Administrator
      • If either the operator or the operator's aircraft have not met the applicable RVSM standards, the aircraft will be referred to as a "non-RVSM" aircraft
    • ATC provides accommodations of non-RVSM aircraft flown by the DOD, Air Ambulance (MEDEVAC) operations, foreign State governments, and aircraft flown for certification and development
    • ATC provides accommodations for non-RVSM aircraft climbing and descending through RVSM airspace to/from flight levels above RVSM
  • Benefits of RVSM:

    • Enhances ATC flexibility, mitigates conflict points, enhances sector throughput, reduces controller workload, and enables crossing traffic
    • Operators gain fuel savings and operating efficiency benefits by flying at more fuel efficient flight levels and on more user preferred routings
  • Flight Level Orientation Scheme:

    • Altitude assignments for direction of flight follow a scheme of odd altitude assignments for magnetic courses 000-179° and even altitudes for magnetic courses 180-359° for flights up to and including FL410 [Figure 1]
  • Approval Policy/Procedures, RVSM Monitoring and Databases:

    • RVSM Authority:

      • FAR 91.180 applies to RVSM operations within the U.S.
      • FAR 91.706 applies to RVSM operations outside the U.S.
      • Both sections require that the operator be authorized prior to operating in RVSM airspace
      • For Domestic RVSM operations, an operator may choose to operate under the provisions of Part 91, Appendix G, Section 9; or if intending to operate outside U.S. airspace, hold a specific approval (OpSpec/MSpec/LOA) under the provisions of Section 3 of Part 91, Appendix G
    • Sources of Information

    • TCAS Equipage:

      • TCAS equipage requirements are contained in FAR 121.356, 125.224, 129.18 and 135.189
      • Part 91 Appendix G does not contain TCAS equipage requirements specific to RVSM, however, Appendix G does require that aircraft equipped with TCAS II and flown in RVSM airspace be modified to incorporate TCAS II Version 7.0 or a later version
    • Aircraft Monitoring:

      • Operators are required to participate in the RVSM altitude-keeping performance monitoring program that is appropriate for the type of operation being conducted
        • The monitoring programs are described in AC 91-85
      • Monitoring is a quality control program that enables the FAA and other civil aviation authorities to assess the in-service altitude-keeping performance of aircraft and operators
    • Purpose of RVSM Approvals Databases:

      • All RVSM designated airspace is monitored airspace
        • ATC does not use RVSM approvals databases to determine whether or not a clearance can be issued into RVSM airspace
      • RVSM program managers do regularly review the operators and aircraft that operate in RVSM airspace to identify and investigate those aircraft and operators flying in RVSM airspace, but not listed on the RVSM approvals databases
    • Registration of U.S. Operators:

      • When U.S. operators and aircraft are granted specific RVSM authority, the Separation Standards Group at the FAA Technical Center obtains PTRS operator and aircraft information to update the FAA maintained U.S. Operator/Aircraft RVSM Approvals database
      • Basic database operator and aircraft information can be viewed on the RVSM Documentation Webpage in the "RVSM Approvals" section
  • Flight Planning into RVSM Airspace:

    • Operators that do not file the correct aircraft equipment suffix on the FAA or ICAO Flight Plan may be denied clearance into RVSM airspace
    • The operator will annotate the equipment block of the FAA or ICAO Flight Plan with an aircraft equipment suffix indicating RVSM capability only after determining that both the operator is authorized and its aircraft are RVSM-compliant
      • An operator may operate in RVSM airspace under the provisions of Part 91, Appendix G, Section 9, without specific authorization and should file "/w" in accordance with suffix policy
      • An operator must get an OpSpec/MSpec/LOA when intending to operate RVSM outside U.S. airspace. Once issued, that operator can file "/w" in accordance with suffix policy
      • An operator should not file "/w" when intending to operate in RVSM airspace outside of the U.S., if they do not hold a valid OpSpec/MSpec/LOA
    • General Policies for FAA Flight Plan Equipment Suffix:

      • Navigation, Communication, and Approach Aid Capabilities
        Navigation, Communication, and
        Approach Aid Capabilities
      • Surveillance Capabilities
        Surveillance Capabilities
      • Aircraft Suffixes allow operators to indicate that the aircraft has both RVSM and Advanced Area Navigation (RNAV) capabilities or has only RVSM capability
        1. The operator will annotate the equipment block of the FAA Flight Plan with the appropriate aircraft equipment suffix [Figure 2/3]
        2. Operators can only file one equipment suffix in block 3 of the FAA Flight Plan
          • Only this equipment suffix is displayed directly to the controller
        3. Aircraft with RNAV Capability-For flight in RVSM airspace, aircraft with RNAV capability, but not Advanced RNAV capability, will file "/W"
          • Filing "/w" will not preclude such aircraft from filing and flying direct routes in en route airspace
      • Navigation, Communication, and Approach Aid Capabilities
        Navigation, Communication, and
        Approach Aid Capabilities
      • Surveillance Capabilities
        Surveillance Capabilities
    • Policy for ICAO Flight Plan Equipment Suffixes:

      1. Operators/aircraft that are RVSM-compliant and that file ICAO flight plans will file "/w" in block 10 (Equipment) to indicate RVSM authorization and will also file the appropriate ICAO Flight Plan suffixes to indicate navigation and communication capabilities
      2. Operators/aircraft that file ICAO flight plans that include flight in Domestic U.S. RVSM airspace must file "/W" in block 10 to indicate RVSM authorization
    • Importance of Flight Plan Equipment Suffixes:

      • Military users, and civilians who file stereo route flight plans, must file the appropriate equipment suffix in the equipment block of the FAA Form 7233-1, Flight Plan, or DD Form 175, Military Flight Plan, or FAA Form 7233-4, International Flight Plan, or DD Form 1801, DOD International Flight Plan
      • All other users must file the appropriate equipment suffix in the equipment block of FAA Form 7233-4, International Flight Plan
      • The equipment suffix informs ATC:
        1. Whether or not the operator and aircraft are authorized to fly in RVSM airspace
        2. The navigation and/or transponder capability of the aircraft (e.g., advanced RNAV, transponder with Mode C)
    • Significant ATC uses of the flight plan equipment suffix information are:

      1. To issue or deny clearance into RVSM airspace
      2. To apply a 2,000' vertical separation minimum in RVSM airspace to aircraft that are not authorized for RVSM, but are in one of the limited categories that the FAA has agreed to accommodate. (See Paragraphs 4-6-10, Procedures for Accommodation of Non-RVSM Aircraft, and 4-6-11, Non-RVSM Aircraft Requesting Climb to and Descent from Flight Levels Above RVSM Airspace Without Intermediate Level Off, for policy on limited operation of unapproved aircraft in RVSM airspace)
      3. To determine if the aircraft has "Advanced RNAV" capabilities and can be cleared to fly procedures for which that capability is required
      • Improperly changing an aircraft equipment suffix and/or adding "NON-RVSM" in the NOTES or REMARKS section (Field 18) while not removing the "W" from Field 10, will not provide air traffic control with the proper visual indicator necessary to detect Non-RVSM aircraft. To ensure information processes correctly for Non-RVSM aircraft, the "W" in Field 10 must be removed. Entry of information in the NOTES or REMARKS section (Field 18) will not affect the determination of RVSM capability and must not be used to indicate a flight is Non-RVSM
  • Pilot RVSM Operating Practices and Procedures:

    • RVSM Mandate:

      • If either the operator is not authorized for RVSM operations or the aircraft is not RVSM-compliant, the pilot will neither request nor accept a clearance into RVSM airspace unless:
        1. The flight is conducted by a non-RVSM DOD, MEDEVAC, certification/development or foreign State (government) aircraft in accordance with Paragraph 4-6-10, Procedures for Accommodation of Non-RVSM Aircraft
        2. The pilot intends to climb to or descend from FL 430 or above in accordance with Paragraph 4-6-11, Non-RVSM Aircraft Requesting Climb to and Descent from Flight Levels Above RVSM Airspace Without Intermediate Level Off
        3. An emergency situation exists
    • Basic RVSM Operating Practices and Procedures:

      • AC 91-85 contains pilot practices and procedures for RVSM
        • Operators must incorporate applicable practices and procedures, as supplemented by the applicable paragraphs of this section, into operator training or pilot knowledge programs and operator documents containing RVSM operational policies
      • AC 91-85 contains practices and procedures for flight planning, preflight procedures at the aircraft, procedures prior to RVSM airspace entry, inflight (en route) procedures, contingency procedures and post flight
      • The following paragraphs either clarify or supplement AC 91-85 practices and procedures
  • Regulation:

    • No person may operate a civil aircraft in airspace designed as RVSM airspace unless:
      • The operator complies with the minimums set forth (appendix G)
      • The operator is authorized by the administrator or the country of register to conduct such operations
    • The administrator may authorize a deviation from the requirements of this section
    • Authorization (via clearance) is required prior to entering the RVSM environment
      • In addition, you are required to comply with the standards of Part 91 Appendix G (Operations in RVSM Airspace)
    • Though not mentioned in FARs, appendix G requires TCAS II Version 7.0 or later
    • Aircraft that fail to file the correct equipment suffix on their flight plan may be denied entry
      • Aircraft with RNAV capability with RNAV but not Advanced RNAV will file /W and will not preclude such aircraft from filing and flying direct routes in RVSM
      • The equipment suffix informs ATC:
        • Whether or not the operator and aircraft are authorized to fly in RVSM airspace
        • The navigation and/or transponder capability of the aircraft
        • Clearance issuing into RVSM
        • To apply a 2,000' vertical separation minimum for those aircraft not RVSM equipped
        • To determine if the aircraft has A-RNAV and can be cleared to fly procedures for which that capability is required
    • Between FL 180 and FL 290, the minimum altitude separation is 1,000' between aircraft
    • However, for flight above FL 290 (primarily due to aircraft equipage and reporting capability; potential error) ATC applied the requirement of 2,000' of separation
    • FL 290, an altitude appropriate for an eastbound aircraft, would be followed by FL 310 for a westbound aircraft, and so on to FL 410, or seven FLs available for flight
    • With 1,000' separation, or a reduction of the vertical separation between FL 290 and FL 410, an additional six FLs become available
    • This results in normal flight level and direction management being maintained from FL 180 through FL 410
    • Because it is applied domestically, it is called United States Domestic Reduced Vertical Separation Minimum, or DRVSM
    • However, there is a cost to participate in the DRVSM program, which relates to both aircraft equipage and pilot training
      • For example, altimetry error must be reduced significantly and operators using RVSM must receive authorization from the appropriate civil aviation authority
    • The aircraft must be equipped with at least one automatic altitude control:
      • Within a tolerance band of ± 65' about an acquired altitude when the aircraft is operated in straight-and-level flight
      • Within a tolerance band of ± 130' under no turbulent conditions for aircraft for which application for type certification occurred on or before April 9, 1997 that are equipped with an automatic altitude control system with flight management/performance system inputs
    • That aircraft must be equipped with an altitude alert system that signals an alert when the altitude displayed to the flight crew deviates from the selected altitude by more than (in most cases) 200'
    • For each condition in the full RVSM flight envelope, the largest combined absolute value for residual static source error plus the avionics error may not exceed 200'
    • Most noteworthy, however, is the economization that aircraft can take advantage of by the higher FLs being available to more aircraft
  • Operating Practices and Procedures:

    • If either the operator or the aircraft, or both, have not received RVSM authorization (non-RVSM aircraft), the pilot will neither request nor accept a clearance into RVSM airspace unless:
      • The flight is conducted by a non-RVSM DOD, Lifeguard, certification/development, or foreign State (government) aircraft in accordance with AIM paragraph 4-6-10
      • The pilot intends to climb to or descend from FL430 or above in accordance with AIM paragraph 4-6-11
      • An emergency situation exists
    • Operators must incorporate Appendix 4 practices and procedures of Guidance 91-RVSM
      • Found on the RVSM Documentation Web page under "Documents Applicable to All RVSM Approvals"
  • Pilot/Controller Phraseology:

    • RVSM Phraseology
      RVSM Phraseology
  • Contingency Actions: Weather Encounters and Aircraft System Failures (after entry)

    • Initial Pilot Actions in Contingency Situations:

      • Initial pilot actions when unable to maintain flight level (FL) or unsure of aircraft altitude-keeping capability:
        • Notify ATC and request assistance as detailed below
        • Maintain cleared flight level, to the extent possible, while evaluating the situation
        • Watch for conflicting traffic both visually and by reference to TCAS, if equipped
        • Alert nearby aircraft by illuminating exterior lights (commensurate with aircraft limitations)
    • Severe Turbulence and/or Mountain Wave Activity (MWA) Induced Altitude Deviations of Approximately 200'

      • Pilot Will:
        • When experiencing severe turbulence and/or MWA induced altitude deviations of approximately 200' or greater, pilot will contact ATC and state "Unable RVSM Due (state reason)" (e.g., turbulence, mountain wave)
        • If not issued by the controller, request vector clear of traffic at adjacent FLs
        • If desired, request FL change or re-route
        • Report location and magnitude of turbulence or MWA to ATC
      • Controller Will:
        • Vector aircraft to avoid merging target with traffic at adjacent flight levels, traffic permitting
        • Advise pilot of conflicting traffic
        • Issue FL change or re-route, traffic permitting
        • Issue PIREP to other aircraft
    • Mountain Wave Activity (MWA) Encounters - General:

      • Pilot Actions:
        • Contact ATC and report experiencing MWA
        • If so desired, pilot may request a FL change or re-route
        • Report location and magnitude of MWA to ATC
      • Controller Actions:

        • Advise pilot of conflicting traffic at adjacent FL
        • If pilot requests, vector aircraft to avoid merging target with traffic at adjacent RVSM flight levels, traffic permitting
        • Issue FL change or re-route, traffic permitting
        • Issue PIREP to other aircraft
        • Note that MWA encounters do not necessarily result in altitude deviations on the order of 200'. The guidance below is intended to address less significant MWA encounters
    • Wake Turbulence Encounters

      • Pilot Actions:
        • Contact ATC and request vector, FL change or, if capable, a lateral offset
      • Controller Actions:
        • Issue vector, FL change or lateral offset clearance, traffic permitting
    • "Unable RVSM Due to" Equipment Failure of Automatic Altitude Control System, Altitude Alerter or All Primary Altimeters

      • Pilot Actions:
        • Contact ATC and state "Unable RVSM Due Equipment"
        • Request clearance out of RVSM airspace unless operational situation dictates otherwise
      • Controller Actions:

        • Provide 2,000' vertical separation or appropriate horizontal separation
        • Clear aircraft out of RVSM airspace unless operational situation dictates otherwise
    • One Primary Altimeter Remains Operational

      • Pilot Will:
        • Cross check stand-by altimeter
        • Notify ATC of operation with single primary altimeter
        • If unable to confirm primary altimeter accuracy, follow actions for failure of all primary altimeters
      • Controller Will:
        • Acknowledge operation with single primary altimeter
    • Transponder Failure

      • Pilot Will:
        • Contact ATC and request authority to continue to operate at cleared flight level
        • Comply with revised ATC clearance, if issued
        • Note that 14 CFR Section 91.215 (ATC transponder and altitude reporting equipment and use) regulates operation with the transponder inoperative
      • Controller Will:

        • Consider request to continue to operate at cleared flight level
        • Issue revised clearance, if necessary
  • Procedures for Accommodation of Non-RVSM Aircraft:

    • 14 CFR Section 91.180 and Part 91 Appendix G enable the FAA to authorize a deviation to operate a non-RVSM aircraft in RVSM airspace
    • General Policies for Accommodation of Non-RVSM Aircraft:

      • The RVSM mandate calls for only RVSM authorized aircraft/operators to fly in designated RVSM airspace with limited exceptions
      • If the operator is not authorized or the aircraft is not RVSM-compliant, the aircraft will be referred to as a "non-RVSM" aircraft
        • YOU: "[Facility], [Callsign], [Flight Level], negative RVSM"
      • Non-RVSM aircraft flights will be handled on a workload permitting basis
        • The vertical separation standard applied between aircraft not approved for RVSM and all other aircraft shall be 2,000'
    • Categories of Non-RVSM Aircraft that may be Accommodated:

      • Subject to FAA approval and clearance, the following categories of non-RVSM aircraft may operate in domestic U.S. RVSM airspace, provided they have an operational transponder:
        • Department of Defense (DOD) aircraft
        • Flights conducted for aircraft certification and development purposes
        • Active air ambulance flights utilizing a "MEDEVAC" call sign
        • Aircraft climbing/descending through RVSM flight levels (without intermediate level off) to/from FLs above RVSM airspace (Policies for these flights are detailed below
        • Foreign State (government) aircraft
    • Methods for operators of non-RVSM aircraft to request access to RVSM Airspace:

      • LOA/MOU:
        • Enter into a Letter of Agreement (LOA)/Memorandum of Understanding (MOU) with the RVSM facility (the Air Traffic facility that provides air traffic services in RVSM airspace). Operators must comply with LOA/MOU
      • File-and-Fly:
        • File a flight plan to notify the FAA of their intention to request access to RVSM airspace
      • NOTE-Priority for access to RVSM airspace will be afforded to RVSM compliant aircraft, then File-and-Fly flights
    • Non-RVSM Aircraft Requesting Climb to and Descent from Flight Levels Above RVSM Airspace Without Intermediate Level Off:

      • File-and-Fly:

        • Operators of Non-RVSM aircraft climbing to and descending from RVSM flight levels should just file a flight plan
      • Non-RVSM aircraft climbing to and descending from flight levels above RVSM airspace will be handled on a workload permitting basis
      • The vertical separation standard applied in RVSM airspace between non-RVSM aircraft and all other aircraft shall be 2,000'
    • Non-RVSM aircraft climbing to/descending from RVSM airspace can only be considered for accommodation provided:

      • Aircraft is capable of a continuous climb/descent and does not need to level off at an intermediate altitude for any operational considerations and
      • Aircraft is capable of climb/descent at the normal rate for the aircraft
    • Required Pilot Calls: The pilot of non-RVSM aircraft will inform the controller of the lack of RVSM approval in accordance with the direction provided above:
      • YOU: "[Facility], [Callsign], [Flight Level], negative RVSM"

Conclusion:

  • Ultimately it is the controller/pilot's responsibility to deconflict from other traffic by time, altitude, or laterally, to avoid a mishap
  • When weather conditions permit, during the time an IFR flight is operating, it is the direct responsibility of the pilot to avoid other aircraft since VFR flights may be operating in the same area without the knowledge of ATC
    • Traffic clearances provide standard separation only between IFR flights
  • Learn more at the FAA's RVSM page and by reading 14 CFR Section 91.180 and Part 91, Appendix
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