Appendix B B-2
2. During the external inspection of aircraft, pay particular attention to the condition of static sources and the condition of the fuselage skin near each static source and any other component affecting altimetry system accuracy. (A qualified and authorized person other than the pilot, e.g., a Flight Engineer (FE) or maintenance personnel may perform this check.)
3. Before takeoff:
• The aircraft altimeters should be set to the local altimeter atmospheric pressure at nautical height (QNH) setting and should display a known elevation (e.g., field elevation) within the limits specified in aircraft operating manuals. The difference between the known elevation and the elevation displayed on the altimeters should not exceed 75 ft.
• The two primary altimeters should also agree within limits specified by the aircraft operating manual/Airplane Flight Manual (AFM), as applicable. An alternative procedure using atmospheric pressure at field elevation (QFE) may also be used.
Note: Both checks should be an emphasis item for training materials.
4. Before takeoff, equipment required for flight in RVSM airspace should be operational, and indications of malfunction should be resolved.
B.4 Procedures Before RVSM Airspace Entry. If any of the required equipment fails prior to the aircraft entering RVSM airspace, the pilot should request a new clearance so as to avoid flight in this airspace. The following equipment should be operating normally at entry into RVSM airspace:
1. Two primary altitude measurement systems.
2. One automatic altitude-control system.
3. One altitude-alerting device.
Note: The operator should ascertain the requirement for an operational transponder in each RVSM area where operations are intended.
B.5 In-Flight Procedures. Incorporate the following policies into flightcrew training and procedures:
1. Flightcrews should comply with aircraft operating restrictions (if required for the specific aircraft group) related to RVSM airworthiness approval. (See paragraph A.10.1.3.)
2. Place emphasis on promptly setting the sub-scale on all primary and standby altimeters to 29.92 in. Hg/1013.25 hPa when climbing through the transition altitude and rechecking for proper altimeter setting when reaching the initial cleared flight level (CFL).
3. In level cruise, it is essential the aircraft is flown at the CFL. This requires particular care is taken to ensure air traffic control (ATC) clearances are fully
Appendix B B-3 understood and followed. Except in contingency or emergency situations, the aircraft should not intentionally depart from CFL without a positive clearance from ATC.
4. During cleared transition between flight levels, the aircraft should not be allowed to overshoot or undershoot the cleared flight level by more than 150 ft (45 m).
Note: It is recommended the level off be accomplished using the altitude capture feature of the automatic altitude-control system, if installed.
5. An automatic altitude-control system should be operative and engaged during level cruise, except when circumstances such as the need to retrim the aircraft or turbulence require disengagement. In any event, adherence to cruise altitude should be done by reference to one of the two primary altimeters.
6. The altitude-alerting system should be operational.
7. At cruise flight level the two primary altimeters should agree within 200 ft (60 m) or a lesser value if specified in the aircraft operating manual. (Failure to meet this condition will require that the altimetry system be reported as defective and notified to ATC.) Note the difference between the primary and stand by altimeters for use in contingency situations.
8. At intervals of approximately 1 hour, make cross-checks between the primary altimeters and the stand-by altimeter.
• The normal pilot scan of flight deck instruments should suffice for altimeter crosschecking on most flights.
• When operating in surveillance airspace (Radar/Automatic Dependent Surveillance-Broadcast (ADS-B)), the initial altimeter cross-check should be performed after level off.
• In oceanic and remote continental (procedural) airspace, a cross-check should be performed and recorded in the vicinity of the point where oceanic and remote continental navigation begins (e.g., on coast out). The readings of the primary and standby altimeters should be recorded and available for use in contingency situations.
• Some aircraft have automatic comparators that compare the two primary altimetry systems. The comparators include a monitoring, warning, and fault function. The faults may be recorded automatically by the system but a record of the differences in the primary altimetry systems may not be easily derived.
Note: In oceanic and remote continental (procedural) airspace, even if the aircraft is equipped with automatic comparators, the crew should be recording the altimeter cross-checks for use in a contingency situation.
9. Normally, the altimetry system being used to control the aircraft should be selected to provide the input to the altitude-reporting transponder transmitting information to ATC.
Appendix B B-4
10. If ATC notifies the pilot of an assigned altitude deviation (AAD) error equal to or exceeding 300 ft (90 m) then the pilot should take action to return to cleared flight level (CFL) as quickly as possible.
11. Contingency procedures after entering RVSM airspace. The flight crew after realizing that they no longer can comply with RVSM requirements (aircraft system failure, weather, lost com, etc.) must request a new clearance from the controller/radio operator as soon as the situation allows. If a new clearance is not available or the nature of the emergency requires rapid action the pilot should notify ATC of their action and contingency procedures. Operators should refer to the RVSM section of the AIM when experiencing abnormal situations and implementing contingency procedures. It is also the responsibility of the crew to notify ATC when the implementation of the contingency procedures is no longer required.
B.6 Post Flight. In making maintenance logbook entries against malfunctions in height-keeping systems, the pilot should provide sufficient detail to enable maintenance to effectively troubleshoot and repair the system. The pilot should detail the actual defect and the crew action taken to try to isolate and rectify the fault. Note the following information when appropriate:
1. Primary and standby altimeter reading.
2. Altitude selector setting.
3. Subscale setting on altimeter.
4. Autopilot used to control the airplane and any differences when the alternate system was selected.
5. Differences in altimeter readings if alternate static ports selected.
6. Use of air data computer selector for fault diagnosis procedure.
7. Transponder selected to provide altitude information to ATC and any difference if alternate transponder or altitude source is manually selected.
B.7 Special Emphasis Items: Flightcrew Training. The following items should also be included in flightcrew training programs:
1. Operators are responsible for knowing the RVSM procedures in the areas of intended operation. Operators starting RVSM operation in an RVSM area of operation new to them should ensure their RVSM programs incorporate RVSM policy and procedures unique to the new area of operations.
Note: Additional specific information on RVSM operational policy and procedures in the domestic U.S., Alaska, Offshore Airspace, and the San Juan flight information region (FIR) can be found in the AIM, Chapter 4, Section 6.
2. Importance of crewmembers cross-checking each other to ensure ATC clearances are promptly and correctly complied with.
Appendix B B-5
3. Use and limitations in terms of accuracy of standby altimeters in contingencies. Where applicable, the pilot should review the application of static source correction error/position correction error (SSEC/PEC) through the use of correction cards.
4. Problems of visual perception of other aircraft at 1,000 ft (300 m) planned separation during night conditions, when encountering local phenomena such as northern lights, for opposite and same direction traffic, and during turns.
5. Characteristics of aircraft altitude capture systems leading to the occurrence of overshoots.
6. Operational procedures and operating characteristics related to Traffic Alert and Collision Avoidance System (TCAS)/Airborne Collision Avoidance System (ACAS) operation in an RVSM operation.
7. Relationship between the altimetry, automatic altitude control, and transponder systems in normal and abnormal situations.
8. Aircraft operating restrictions (if required for the specific aircraft group) related to RVSM airworthiness approval. (See paragraph A.10.1.3.)
Appendix C C-1 APPENDIX C. OPERATIONS IN OCEANIC AND REMOTE CONTINENTAL
AIRSPACE C.1 Introduction. Reduced Vertical Separation Minimum (RVSM) was initially implemented in North Atlantic Minimum Navigation Performance Specifications (MNPS) Airspace in March 1997 (MNPS Airspace is currently planned to be renamed North Atlantic (NAT) High Level Airspace). Since then, RVSM operations have been implemented almost worldwide.
C.1.1 Basic Concepts for Contingencies.
1. With the increase over the years of flight in oceanic and remote airspace, contingency procedures have been developed to minimize the disruption of Air Traffic Services when unable to comply with a given air traffic control (ATC) clearance. Contingency procedures, when such events may be put in place, help to provide the continued safety of air navigation. Operators and pilots conducting oceanic and remote airspace operations should ensure their familiarity with and the actions expected of pilots in such contingency situations.
2. Specific Guidance. The basic concepts for contingencies in oceanic airspace are contained in International Civil Aviation Organization (ICAO) Doc. 4444, Procedures for Air Navigation Services—Air Traffic Management (PANS— ATM), Chapter 15.2, Special Procedures for In-Flight Contingencies in Oceanic Airspace.
3. Operators are responsible for knowing the RVSM procedures in the areas of intended operation. Operators starting RVSM operation in an RVSM area of operation new to them should ensure their RVSM programs incorporate RVSM policy and procedures unique to the new area of operations.
Note: ICAO Document 7030, Regional Supplementary Procedures, provides differences for individual regions of the world.
C.1.2 Strategic Lateral Offset Procedures (SLOP). SLOP are approved oceanic procedures allowing aircraft to fly on a parallel track to the right of the center line relative to the direction of flight to mitigate the lateral overlap probability due to increased navigation accuracy and wake turbulence encounters. Unless specified in the separation standard, an aircraft’s use of these procedures does not affect the application of prescribed separation standards. Implementation of strategic lateral offset procedures must be coordinated among the States involved. Procedures for the conduct of SLOP are contained in ICAO Doc 4444, PANS—ATM, Chapter 16.5, Strategic Lateral Offset Procedures (SLOP).
Note: In domestic U.S. airspace, pilots must request clearance to fly a lateral offset. Strategic lateral offsets flown in oceanic airspace do not apply. (See FAA Aeronautical Information Manual (AIM), Guidance on Wake Turbulence.)
Appendix C C-2 C.1.3 Guidance To The Pilot In The Event Of Equipment Failures Or Encounters With Turbulence After Entry Into RVSM Airspace (Including Expected ATC Actions).
C.1.3.1 The following material is provided with the purpose of giving the pilot guidance on actions to take under certain conditions of equipment failure and encounters with turbulence. It also describes the expected ATC controller actions in these situations. It is recognized the pilot and controller will use judgment to determine the action most appropriate to any given situation. The guidance material recognizes for certain equipment failures, the safest course of action may be for the aircraft to maintain the assigned flight level (FL) and route while the pilot and controller take precautionary action to protect separation. For extreme cases of equipment failure, however, the guidance recognizes the safest course of action may be for the aircraft to depart from the cleared FL or route by obtaining a revised ATC clearance; or if unable to obtain prior ATC clearance, executing the established ICAO Doc. 4444 and Doc. 7030 contingency maneuvers for the area of operation.
Note: Paragraph C.1.4 provides an expanded description of the scenarios detailed below.
C.1.3.2 Contingency Scenarios. The following paragraphs summarize pilot actions to mitigate the potential for conflict with other aircraft in certain contingency situations.
Figure C.1-1. Scenario 1 The pilot is: 1) unsure of the vertical position of the aircraft due to the loss or degradation of all primary altimetry systems; or 2) unsure of the capability to maintain cleared flight level (CFL) due to turbulence or loss of all automatic altitude control systems.
The pilot should: ATC can be expected to:
Maintain CFL while evaluating the situation;
Watch for conflicting traffic both visually and by reference to ACAS (TCAS), if equipped;
If considered necessary, alert nearby aircraft by:
1) Making maximum use of exterior lights;
2) Broadcasting position, FL, and intentions on 121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency may be used).
Notify ATC of the situation and intended course of action. Possible courses of action include:
Obtain the pilot’s intentions and pass essential traffic information.
1) Maintaining the CFL and route, provided 1) If the pilot intends to continue in RVSM
Appendix C C-3 The pilot should: ATC can be expected to:
ATC can provide lateral, longitudinal, or conventional vertical separation.
airspace, assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or increased vertical separation, and if so, apply the appropriate minimum.
2) Requesting ATC clearance to climb above or descend below RVSM airspace if the aircraft cannot maintain CFL and ATC cannot establish adequate separation from other aircraft.
2) If the pilot requests clearance to exit RVSM airspace, accommodate expeditiously, if possible.
3) Executing the ICAO Doc. 4444 contingency maneuver to offset from the assigned track and FL, if ATC clearance cannot be obtained and the aircraft cannot maintain CFL.
3) If adequate separation cannot be established and it is not possible to comply with the pilot’s request for clearance to exit RVSM airspace, advise the pilot of essential traffic information, notify other aircraft in the vicinity and continue to monitor the situation.
4) Notify adjoining ATC facilities/sectors of the situation.
Figure C.1-2. Scenario 2 There is a failure or loss of accuracy of one primary altimetry system (e.g., greater than 200 ft difference between primary altimeters).
The Pilot should:
Cross-check standby altimeter, confirm the accuracy of a primary altimeter system, and notify ATC of the loss of redundancy. If unable to confirm primary altimeter system accuracy, follow pilot actions listed in the preceding scenario.
C.1.4 Expanded Equipment Failure and Turbulence Encounter Scenarios. Operators may consider this material for use in training programs.
Appendix C C-4 Figure C.1-3. Expanded Scenario 1 All automatic altitude control systems fail (e.g., Automatic Altitude Hold).
The pilot should: ATC can be expected to:
Initially maintain CFL, and Evaluate the aircraft’s capability to maintain altitude through manual control.
Subsequently watch for conflicting traffic both visually and by reference to TCAS, if equipped.
If considered necessary, alert nearby aircraft by:
1) Making maximum use of exterior lights;
2) Broadcasting position, FL, and intentions on 121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency may be used).
Notify ATC of the failure and intended course of action. Possible courses of action include:
1) Maintaining the CFL and route, provided the aircraft can maintain level.
1) If the pilot intends to continue in RVSM airspace, assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or increased vertical separation, and if so, apply the appropriate minimum.
2) Requesting ATC clearance to climb above or descend below RVSM airspace if the aircraft cannot maintain CFL and ATC cannot establish lateral, longitudinal, or conventional vertical separation.
2) If the pilot requests clearance to exit RVSM airspace, accommodate expeditiously, if possible.
3) Executing the ICAO Doc. 4444 contingency maneuver to offset from the assigned track and FL, if ATC clearance cannot be obtained and the aircraft cannot maintain CFL.
3) If adequate separation cannot be established and it is not possible to comply with the pilot’s request for clearance to exit RVSM airspace, advise the pilot of essential traffic information, notify other aircraft in the vicinity, and continue to monitor the situation.
4) Notify adjoining ATC facilities/sectors of the situation.
Appendix C C-5 Figure C.1-4. Expanded Scenario 2 Loss of redundancy in primary altimetry systems.
The pilot should: ATC can be expected to:
If the remaining altimetry system is functioning normally, couple that system to the automatic altitude control system, notify ATC of the loss of redundancy, and maintain vigilance of altitude keeping.
Acknowledge the situation and continue to monitor progress.
Figure C.1-5. Expanded Scenario 3 All primary altimetry systems are considered unreliable or fail.
The pilot should: ATC can be expected to:
Maintain CFL by reference to the standby altimeter (if the aircraft is so equipped).
Alert nearby aircraft by:
1) Making maximum use of exterior lights;
2) Broadcasting position, FL, and intentions on
121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency may be used).
Consider declaring an emergency. Notify ATC of the failure and intended course of action.
Possible courses of action include:
Obtain pilot’s intentions, and pass essential traffic information.
1) Maintaining CFL and route provided ATC can provide lateral, longitudinal, or conventional vertical separation.
1) If the pilot intends to continue in RVSM airspace, assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or increased vertical separation, and if so, apply the appropriate minimum.
2) Requesting ATC clearance to climb above or descend below RVSM airspace if ATC cannot establish adequate separation from other aircraft.
2) If the pilot requests clearance to exit RVSM airspace, accommodate expeditiously, if possible.
3) Executing the ICAO Doc. 4444 contingency maneuver to offset from the assigned track and FL, if ATC clearance cannot be obtained.
3) If adequate separation cannot be established and it is not possible to comply with the pilot’s request for clearance to exit RVSM airspace, advise the pilot of essential traffic information, notify other aircraft in the vicinity, and continue to monitor the situation.
4) Notify adjoining ATC facilities/sectors of the situation.
Appendix C C-6 Figure C.1-6. Expanded Scenario 4 The primary altimeters diverge by more than 200 ft (60 m).
The pilot should:
Attempt to determine the defective system through established trouble-shooting procedures and/or comparing the primary altimeter displace to the standby altimeter (as corrected by the correction cards, if required).
If the defective system can be determined, couple the functioning altimeter system to the altitude keeping device.
If the defective system cannot be determined, follow the guidance in Scenario 3 for failure or unreliable altimeter indications of all primary altimeters.
Figure C.1-7. Expanded Scenario 5 Turbulence (greater than moderate) which the pilot believes will impact the aircraft’s capability to maintain FL.
The pilot should: ATC can be expected to:
Watch for conflicting traffic both visually and by reference to TCAS, if equipped.
If considered necessary, alert nearby aircraft by:
1) Making maximum use of exterior lights;
2) Broadcasting position, FL, and intentions on 121.5 MHz (as a back-up, the VHF inter-pilot air-to-air frequency may be used).
Notify ATC of intended course of action as soon as possible. Possible courses of action include:
1) Maintaining CFL and route provided ATC can provide lateral, longitudinal, or conventional vertical separation.
1) Assess traffic situation to determine if the aircraft can be accommodated through the provision of lateral, longitudinal, or increased vertical separation, and if so, apply the appropriate minimum.
2) Requesting flight level change, if necessary.
2) If unable to provide adequate separation, advise the pilot of essential traffic information and request pilot’s intentions.
Appendix C C-7 The pilot should: ATC can be expected to:
3) Executing the ICAO Doc. 4444 contingency maneuver to offset from the assigned track and FL, if ATC clearance cannot be obtained and the aircraft cannot maintain CFL.
3) Notify other aircraft in the vicinity and monitor the situation.
4) Notify adjoining ATC facilities/sectors of the situation.
C.1.5 Transponder Failure. The provider States will determine the specific actions ATC will take in the event of transponder failure in RVSM.
C.1.6 ICAO Regional Supplementary Procedures (SUPPS) and State Specific Guidance.
Operators are responsible for knowing the RVSM procedures in the areas of intended operation. Operators starting RVSM operation in an RVSM area of operation new to them should ensure their RVSM programs incorporate RVSM policy and procedures unique to the new area of operations.
C.1.6.1 Operators should review ICAO Document 7030, Regional Supplementary Procedures, and State Aeronautical Information Publications prior to starting RVSM operations in an area new to the operator.
C.1.7 Additional Information. Additional information regarding RVSM operations can be found on the FAA RVSM Documentation Web page at:
https://www.faa.gov/air_traffic/separation_standards/rvsm/documentation/.
Appendix D D-1 APPENDIX D. REVIEW OF ICAO DOCUMENT 9574 D.1 ICAO Document 9574.
D.1.1 International Civil Aviation Organization (ICAO) Doc. 9574, Manual on the Implementation of a 300 m (1,000 ft) Vertical Separation Minimum Between FL 290-FL 410 Inclusive, covers the overall analysis of factors for achieving an acceptable level of safety in a given airspace system. The major factors are passing frequency, lateral navigation accuracy, and vertical overlap probability. Vertical overlap probability is a consequence of errors in adhering accurately to assigned flight level (FL), and this is the only factor addressed in the present document.
D.1.2 In ICAO Doc. 9574, Section 2.3.1 restated the vertical overlap probability requirement as the aggregate of height-keeping errors of individual aircraft, which must lie within the TVE distribution expressed as the simultaneous satisfaction of the following four requirements:
D.1.2.1 The proportion of height-keeping errors beyond 300 ft (90 m) in magnitude must be less than 2.0x10-3;
D.1.2.2 The proportion of height-keeping errors beyond 500 ft (150 m) in magnitude must be less than 3.5x10-6;
D.1.2.3 The proportion of height-keeping errors beyond 650 ft (200 m) in magnitude must be less than 1.6x10-7; and D.1.2.4 The proportion of height-keeping errors between 950 ft (290 m) and 1,050 ft (320 m) in magnitude must be less than 1.7x10-8.
D.1.3 The following characteristics presented in ICAO Doc. 9574 were developed to satisfy the distributional limits in paragraph D.1.2.1, and to result in aircraft airworthiness having negligible effect on meeting the requirements in paragraphs D.1.2.2, D.1.2.3, and D.1.2.4.
They are applicable statistically to individual groups of nominally identical aircraft operating in the airspace. These characteristics describe the performance the groups need to be capable of achieving in service, exclusive of human factors errors and extreme environmental influences, if the airspace system Total Vertical Error (TVE) requirements are to be satisfied. The following characteristics are the basis for development of this document:
D.1.3.1 The mean altimetry system error (ASE) of the group must not exceed ±80 ft (±25 m);
D.1.3.2 The sum of the absolute value of the ASEmean for the group and ASE3 SD within the group must not exceed 245 ft (75 m); and D.1.3.3 Errors in altitude keeping must be symmetric about a mean of 0 ft (0 m), must have a standard deviation (SD) not greater than 43 ft (13 m), and the error