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Performance Based Communications and Surveillance (PBCS)

Communications and Surveillance

At first, we thought the entire data link process was incredibly difficult and something we would never master, until we did. A piece of cake. But things are changing on March 29th, 2018.

There are rumors the March 29th, 2018 implementation date is going to change. But even if it does, if you want to use data link over in the North Atlantic High Level Airspace, you need to pay attention. Your existing Letter of Authorization or Operations Specification (A056) is about to become invalid.

Wait a minute, you say. You pay attention to these things. It is February and all this happens NEXT MONTH. Why weren't you told about this?


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Photo: ICAO Doc 9869 Cover Page (Previous versions are out of date!)

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Photo: Operational Concept PBCS, ICAO Doc 9869, Figure 2-1

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Updates, Please!

So if all this was news to everyone (except my POI) on February 1st, how can we possibly stay up to date? I've found the best source is through an invention of a friend of mine, Mark Zee, known as Flight Service Bureau (also available through OpsGroup). Here is what they have to say:

In English, Please

PBCS? Remember when PBN was a mystery? Performance Based Navigation was a game changer because we started measuring how well our navigation systems did to ensure we kept within a defined chunk of airspace (known as the "confinement" area). Well, Performance Based Communications and Surveillance has the same goal (avoid loss of separation between aircraft) but the mechanism is a bit different.

Breaking down the component parts . . .

Required Communication Performance measures how long it takes for ATC to send you (the pilot) a message, for you to respond, and for them to get your answer. RCP-240, for example, means it can take a maximum of 240 seconds.

Required Surveillance Performance measures the number of seconds it takes for your aircraft to send surveillance data to ATC.

Timing . . .

The biggest impact of PBCS on us operators happens on March 29, 2018, when our ability to use data link will start to require monitoring our PBCS results. How well you do could preclude your use of some of the North Atlantic. More about this: North Atlantic High Level Airspace.

Expanded domestic use in the US is supposed to start in 2018, with full en route use around 2025.

Bottom-line on Top

  1. If you are an authorized data link user (other than for domestic US purposes), you need an A056 authorization written with PBCS noted. This applies, even if you already have an A056 that was written prior to this change.
  2. PBCS is designed to ensure ATC can keep an eye on you and communicate with you in a timely manner. More about this: Purpose.
  3. ATC will monitor how quickly you respond to their messages and any answer that takes longer than 60 seconds will flag you and could harm your efforts to the PBCS authorization.

If You Already Have A056 (The pre-2018 version)

As of January 2018, you have until March 29, 2018 to get A056 to use your data link outside the United States.

Where does it say March 29, 2018?

NAT PBCS Implementation Plan, p. 5, Task ID B-2]

  • Task Descriptor: Target dates for PBCS and relevant ATM operations
  • Complete by: 28 March 2018 target date

Is my old A056 valid after March 29, 2018?

No, at least that is what "everyone" is saying. I confirmed this with our POI who explained that FAA Order 8900.1, §A056 no longer supports the old A056 template which has columns for PBCS needed for the current authorization.

Purpose

Remember that data link does more than just spare you the need to make frequent position reports and listen to an HF. Its primary purpose is to allow you to fly in airspace where "they" will be packing more and more airplanes. PBCS furthers that goal by ensuring "they" can keep an eye on you (through ADS-C) and can contact you in a more expeditious manner (through CPDLC).

[ICAO Doc 10037, 1.1.3.3] Performance-based communication and surveillance (PBCS) is a concept that applies required communication performance (RCP) and required surveillance performance (RSP) specifications to ensure appropriate performance levels for relevant ATM operations (e.g. application of a reduced separation minimum). Information on the performance based communication and surveillance (PBCS) concept and guidance material on its implementation are contained in the Performance-based Communication and Surveillance (PBCS) Manual (Doc 9869).

[ICAO Doc 9869, ¶2.1.5] Given the airspace characteristics and other capabilities and performances, the RCP/RSP specification is used to characterize the communication and surveillance capabilities and performances that need to exist for the controller/system to first — detect an out-of-conformance, second — intervene and third — resolve a conflict. It should not be implied that all communication and surveillance capabilities need to meet the RCP/RSP specification. However, in addition to the RCP/RSP specification applicable to the intervention capability, other RCP and/or RSP specifications may be appropriate for specific operations that require different performance characteristics. For example, this dependency may be related to:

  1. functional differences in the means of communication or surveillance, such as between voice and data (i.e. providing interactive capability versus providing air-ground automation integration capability);
  2. an increase in communications due to an increase in airspace capacity (e.g. when increasing airspace capacity, the controller depends on a CPDLC and ADS-C to maintain an acceptable workload and suitable performance of the very high frequency (VHF) voice communication to intervene in time-critical situations); and
  3. a contingency procedure in the event that normal communication systems fail (e.g. when implementing a separation minimum predicated on communication and surveillance performances, the contingency procedure requires an alternative means of communication that enables the controller to establish communications with an aircraft after the normal means fail to obtain position information and intervene, as necessary).

[ICAO Doc 9869, ¶2.2.1.1] The operational requirements of an RCP specification apply to the controller’s communication and intervention capability. These requirements also define parameter values for operational (end-to-end) RCP transaction times, RCP continuity, RCP availability and RCP integrity, as well as their allocated values (e.g. required communication monitored performance (RCMP), required communication technical performance (RCTP) and, when applicable, human performance). An underlying assumption in the application of RCP is the compatibility and interoperability of the supporting system components, in accordance with interoperability standards.

[ICAO Doc 9869, ¶2.2.1.2] An RCP specification is identified by a designator (e.g. RCP 240) to simplify the RCP designator naming convention and to make the RCP transaction time readily apparent to airspace planners, aircraft manufacturers and operators. The designator represents the maximum communication transaction time after which the initiator should revert to an alternative procedure (or RCP expiration time).

[ICAO Doc 9869, ¶2.4.1.1] The operational requirements of an RSP specification apply to the surveillance services and define parameter values for surveillance data transit times, RSP continuity, RSP availability and RSP integrity, as well as allocated values (e.g. required surveillance monitored performance (RSMP), required surveillance technical performance (RSTP) and, when applicable, human performance). When applying RSP, it is assumed that that the supporting system components are compatible and interoperable, in accordance with interoperability standards.

[ICAO Doc 9869, ¶2.4.1.2] An RSP specification is identified by a designator (e.g. RSP 180) in order to simplify the designator naming convention and to make the required surveillance data delivery time readily apparent to airspace planners, aircraft manufacturers and operators. The designator represents the value for the surveillance data delivery time when the surveillance data delivery is considered overdue.

[ICAO Doc 9869, ¶2.4.1.10] RSP 180 may be applied to maintain the performance for normal means of surveillance, which supports controller intervention capability in procedurally controlled airspace, where separation minimum applied is predicated on surveillance performance.

[ICAO Doc 9869, ¶2.4.4.12.1] For RSP 180, RSP availability is ensured initially in contract/service agreements with the CSP and approval of aircraft ADS-C equipment. Post-implementation monitoring evaluates service availability from unplanned outage events on a per centre basis if the outage exceeds 10 minutes and if it affects multiple aircraft. The service availability requirements are allocated exclusively to the CSP, and assume that failed ADS-C components within the ANSP would not significantly contribute to loss of ADS-C.

[ICAO Doc 9869, ¶2.4.1.11] RSP 400 may be applied to maintain the performance for emerging technology (e.g. satellite voice) used to provide normal means of surveillance supporting controller intervention capability in procedurally controlled airspace, where the separation minimum being applied is based on position reporting at compulsory reporting points. RSP 400 might also be applied to maintain the performance required for emerging technologies used to provide alternative means of surveillance, that may be required in combination with the normal means of surveillance, to which RSP 180 is applied.

Flight Plan

Your flight plan needs several Block 10A and 18 items to allow you to fly in airspace that requires PBCS.

[ICAO Doc 9869, ¶4.4.1 When filing RCP/RSP capabilities, the aircraft operator should ensure that the planned use of associated communication and surveillance capabilities for the flight will be in accordance with regulations, policies and procedures in control areas for the flight, as published by the applicable States in their AIPs (or equivalent publications).

Note.— RCP/RSP capabilities are inserted only when the descriptors J2 through J7 for CPDLC, M1 through M3 for SATVOICE, and/or D1 for ADS-C, are also inserted. While RCP/RSP capability denotes performance, the descriptors J2 through J7, M1 through M3 and D1 in item 10 (see Table 4-1) denote the interoperability for the aircraft equipment. Guidance on filing J2 through J7 and D1 descriptors is contained in Doc 10037. Guidance on filing M1 through M3 descriptors is contained in Doc 10038.

[ICAO Doc 9869, ¶4.4.2 The aircraft operator should ensure that the proper denotation of PBCS capabilities are included in the ICAO flight plan.

Note 1.— Refer to ICAO Doc 4444, 4.4.1.4 and Appendix 2, for flight plan requirements.

Note 2.— The inclusion of PBCS capability in the filed flight plan indicates that the relevant aircraft equipment is approved and serviceable, and that the operator is eligible (e.g. flight crew training and qualification) to use the equipment for PBCS operations. If these conditions are not met, PBCS capability should not be included in the flight plan. Refer to 4.3.4 for guidance on operator eligibility for PBCS operations.

[ICAO Doc 9869, ¶4.4.3 In Item 10 of the flight plan, the aircraft operator should insert one or more descriptors, as appropriate, listed in Table 4-1, to identify an aircraft’s RCP capability:

Item 10a. Radio communication, navigation and approach aid equipment and capabilities Descriptor
CPDLC RCP 400 P1
CPDLC RCP 240 P2
SATVOICE RCP 400 P3

[ICAO Doc 9869, ¶4.4.4] In Item 18 of the flight plan, the aircraft operator should file the RSP capability by inserting the indicator SUR/ followed by the appropriate designator, with no spaces, for the RSP specification (e.g. RSP400 or RSP180).

Note.— The ATS unit uses the flight plan information to determine when to apply particular ATM operations that are dependent on the capability and to configure the system (e.g. set timer threshold values) for efficient operation when required communication and/or surveillance performance varies.

Aircraft Eligibility

There are several steps needed to get PBCS authorization, the first of which is either a Statement of Compliance or something in lieu of that.

[AC 90-117, ¶3.3]

  • Due to the complexity of the criteria to determine eligibility, the operator must obtain a statement of compliance (SOC) from the entity that owns the design approval for their data link installation. This may be the aircraft manufacturer, the operator, the manufacturer of the data link system, or another party. The statement of compliance should be provided in the AFM, AFM Supplement, or other acceptable document. Table C-3, Preferred Original Equipment Manufacturer Annotation, provides an example of a statement of compliance. The statement of compliance must indicate the aircraft data link system meets the aircraft-allocated requirements of Required Communication Performance (RCP) and Required Surveillance Performance (RSP) specifications.
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    Photo: Preferred OEM Annotation, AC 90-117, Table C-3

  • In lieu of the SOC stated in the AFM, AFM Supplement, or other acceptable documentation, operators may provide a detailed submission to the FAA validating that the aircraft’s current system meets the RCP/RSP applicable requirements. As a minimum, this submission should include information on avionics continuity, integrity, availability, and safety and monitoring/alerting requirements (refer to RTCA DO-306/ED-122).

Specification

So how do you know you are good enough for PBCS? Simple, your RCP and RSP have to be low enough.

[ICAO Doc 9869, ¶2.2.1.13] RCP 240 may be applied to maintain the performance for normal means of communication, which supports controller intervention capability in procedurally controlled airspace, where the separation minimum applied is predicated on communication performance.

[ICAO Doc 9869, ¶2.2.4.12.1] For RCP 240, RCP availability is ensured initially in contract/service agreements with the CSP and approval of aircraft CPDLC equipment. Post-implementation monitoring evaluates service availability from unplanned outage events on a per centre basis, if the outage exceeds 10 minutes and if it affects multiple aircraft. The service availability requirements are allocated exclusively to the CSP, and assume that failed CPDLC components within the ANSP would not significantly contribute to loss of the CPDLC service.

[ICAO Doc 9869, ¶2.2.1.14] RCP 400 may be applied to maintain the performance for emerging technology (e.g. satellite voice) used to provide normal means of communication supporting controller intervention capability in procedurally controlled airspace, where the separation minimum applied is based on position reporting at compulsory reporting points. RCP 400 may also be applied to maintain the performance required for emerging technologies used to provide alternative means of communication, that may be required in combination with the normal means of communication, to which RCP 240 is applied.

Monitoring

PBN was a game changer in the world of operating from Point A to Point B; instead of policing the equipment used to navigate, we started monitoring the accurancy of the navigation performance. PBCS is providing a similar game change; our communications and surveillance performance will now be monitored and reported. PBN and PBCS will together allow the system to fit more and more aircraft into the tightest airspace.

Regulatory

[ICAO Annex 11, ¶3.3.5.2] Where RCP/RSP specifications are applied, programmes shall be instituted for monitoring the performance of the infrastructure and the participating aircraft against the appropriate RCP and/or RSP specifications, to ensure that operations in the applicable airspace continue to meet safety objectives. The scope of monitoring programmes shall be adequate to evaluate communication and/or surveillance performance, as applicable.

[ICAO Doc 9869, ¶4.3.4.7] The aircraft operator should participate in local and regional PBCS monitoring programmes, which are applicable to the aircraft operator’s route system, and should provide the following information to the appropriate PBCS monitoring entities specified in AIPs (or equivalent publications):

  1. operator name;
  2. operator contact details; and
  3. other coordination information.

U.S. Aircraft

The FAA says they've been tracking this since 2009 and that you can get your aircraft's record here: https://www.faa.gov/air_traffic/separation_standards/PBCS_Monitoring/. As of January 2018, only two six-month periods were available (July - December 2015 and January - June 2017). My aircraft was not on the list. I clicked on the provided link and emailed the administrator who gave me my results about a week later.

Authorization

You will need A056 to operate data link with the provisions of PBCS, but you don't need to have PBCS to have A056. You just won't be able to do as much with your authorization. See North Atlantic High Level Airspace for an example.

[FAA Order 8900.1, §A056, ¶A.] Template A056 contains specific operational limitations and provisions for granting authorization to operators of aircraft under part 91, 121, 125, 135, or 91 subpart K to conduct data link communications using aircraft systems that are certificated for air–ground air traffic services (ATS).

1) Parts 91, 121, 125, and 135 operators, and part 91K program managers conducting flight operations in oceanic and remote airspace may use data link communications systems (i.e., Future Air Navigation System (FANS) (FANS-1/A or equivalent)). Operations using data link communications within domestic airspace require very-high frequency (VHF) radios called very-high frequency digital link Mode 2 (VDL-2), compatible with ATS.

5) An exception to the requirement for data link communication systems is the FANS-1/A system in oceanic or remote airspace. The FANS-1/A communications system can only be approved for data link operations in oceanic and remote area airspace. FANS-1/A systems are not interoperable with the VDL-2 infrastructure for domestic data link communications.

[AC 90-117, ¶5.1.1] Application Process. Operators must contact their principal operations inspector (POI) to begin the application process for an OpSpec/MSpec/LOA A056 authorization. A compliance guide is available at: https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs400/afs470/datacomm/. This guide expedites the compliance process as it condenses into one location the information required for data link operations.

See Also

Performance Based Communications and Surveillance (PBCS)

Regional: North Atlantic

References

Advisory Circular 90-117, Data Link Communications, 10/3/17, Department of Transportation

FAA Orders 8400 and 8900

ICAO Annex 11 - Air Traffic Services, International Standards, Annex 11 to the Convention on International Civil Aviation, 14th Edition, July 2016

ICAO Doc 9869, Performance-based Communication and Surveillance (PBCS) Manual), Second Edition, 2017, International Civil Aviation Organization

ICAO Doc 10037, Global Operational Data Link (GOLD) Manual, First Edition, 2017, International Civil Aviation Organization

NAS Data Communications Guide

NAT PBCS Implementation Plan, v-2017-1, NAT IMG Decision 50/3

Revision: 20180210
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