What to Know About ICAO Airspace Plans

What are the upcoming airspace plans from ICAO? How do these impact all aspects of General Aviation, including business aircraft? Ken Elliott concludes his series on airspace plans with a discussion about ICAO…

Ken Elliott  |  12th March 2018
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Ken Elliott
Ken Elliott

Ken Elliott is a veteran with 52 years of aviation experience, focussed on avionics in General and Business...

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Ken Elliott discusses airspace plans and how they impact all aspects of General Aviation, including business aircraft. In a three-part series he covers the US, Europe and ICAO, respectively, concluding this month with ICAO…

The International Civil Aviation Organization (ICAO), headquartered in Montreal, has 191-member states with a 36-member governing council. It serves as the global forum of States for international civil aviation developing policies and standards, with a vision to “achieve the sustainable growth of the global civil aviation system”.

Like any other agency, ICAO creates operational principles in the form of Standards and Recommended Practices (SARPs), focusing on safety management. It also develops Procedures for Air Navigation Services (PANS) and regional Supplementary Procedures (SUPPs).

From a regulatory perspective, ICAO oversees international aviation safety, security, efficiency and environmental protection. The organization also regulates operating practices and procedures that involve the technical field of aviation.

At a higher level, ICAO creates plans and guidance for its membership to use as a template in their regional Air Traffic Management (ATM) applications.

Being globally focused, it also adjusts and adopts mature and significantly impacting plans, such as Europe’s SESAR and the US NextGen, both originally initiated by the ‘ICAO Global ATM Operational Concept’.

Countries such as Australia closely abide by the intent of ICAO’s plans, ensuring their ATM operation is “a dynamic, integrated management of air traffic and airspace, operating safely, economically and efficiently — through the provision of facilities and seamless services in collaboration with all parties and involving airborne and ground-based functions” as defined by ICAO.

Member countries develop their own airspace plans from ICAO framework documents, partially because these documents call out for states to develop their own regional and national ATM Plans and State Safety Programs. These documents include:

  • Global Air Navigation Plan (GANP)
  • Global Aviation Safety Plan (GASP)

States with complex and individual airspace characteristics such as Russia, China and Brazil (and partially because of their greater military control over civil aircraft activity) are still fully cooperative and engaging with ICAO recommendations.

This is crucial where their airspaces meet and integrate with international water and remote terrain regions.

At a Working Level

As we find with regional plans, once you dig below the surface there is an enormous amount of data generated from years of committee level effort, providing guidance that keeps airspaces safe and efficient.

ICAO sees airspace improvements as a series of block upgrades. These upgrades are scalable to a regional level, including both their applicability and their timing. Ironically, the content of these blocks is leveraged from FAA and Eurocontrol programs already in place or underway.

This ensures that ICAO and their regional partners are in step (and particularly refers to Block 0 and 1 modules).

‘Blocks’ identified under the Aviation System Block Upgrade (ASBU) include modules performing as the individual cubes in a digital ‘Rubik’s Cube’. There are four major timeline Blocks with target implementation dates as follows:

  • Block 0 – 2013 and still current
  • Block 1 – 2019
  • Block 2 – 2025
  • Block 3 – 2031 and onward

 ICAO aligns its timeline block upgrades against performance improvement areas and there are four of these:

  • Airport operations
  • Globally interoperable systems and data - through System Wide Information Management (SWIM)
  • Optimum capacity and flexible flights – through collaborative Air Traffic Management (ATM)
  • Efficient flight paths

Figure 1 (below) shows these performance improvement areas as threads and modules falling within each timeline block.


FIGURE 1: Elements of ICAO's Working Plan, Showing Relationship of Performance Improvement Areas, Blocks, Threads and Modules

Elements of ICAO's Working Plan


(Note: All Tables and Figures in this article are courtesy of ICAO or derived from ICAO material.)

Table A (below), meanwhile breaks open a single thread and associated Modules – in this case under the Performance Improvement Area 1 (Airport Operations).

TABLE A: Single Thread & Associated Modules

Single Thread and Associated Modules

Table B (below) lists all the Threads, Modules & Blocks for Performance Improvement Area 4 - Efficient Flight Path. This Performance Improvement Area includes the use of forward-looking technologies and is an example of areas that may directly impact Business Aviation over the long-term.

TABLE B: Threads, Modules and Blocks for Performance Improvement, Area 4 (Efficient Flight Path)

Threads, Modules and Blocks for Performance Improvement Area 4 - Efficient Flight Path


In Table B, for Block 0 (B0-), the proven components of the performance improvement are already in place, as of 2013. The target member states may implement these Modules anytime from 2013 and ideally by the close of 2018.

The modules were completed and proven prior to 2013, by either FAA or Eurocontrol, via implementation at specific airports, routes and flown by identified operators, usually a major air carrier.

These modules and their components will continue to be applied regionally adapting to the distinct local variations, as they apply.

So for example, Block 0 Modules will still be applied at different levels of maturity, in different regions of the world, beyond 2018.

Block 1 Modules are also well under way with all their components anticipated to be in place by 2019. They will subsequently be implemented and utilized by member states between 2019 and 2024.

Following Block 1 will be Block 2, functioning between 2025 and 2030, and then Block 3 commencing in 2031. Timeline dates have shifted and may well do so again, normally to the right.

The primary guidance material covering the implementation of Block content is the ‘Working Document for the Aviation System Block Upgrades’. This important document is further supported by several granular level documents pertaining to specific applications.

Table C (below) takes the Block Thread of Trajectory Based Operations (TBO) - ‘Improved Safety and Efficiency through the initial application of Data Link En‐Route’ from Performance Improvement Area 4.

TABLE C: Module B0-TBO in Greater Detail
(see red bordered item in Table B, above)

Module B0-TBO in Greater Detail


Importantly, ICAO monitors the implementation progress of its Performance Improvements by the use of Key Performance Areas (KPA), measuring each module, to gauge its effectiveness.

Note how Table C introduces the Technology in support of the Elements of the Module. It includes both ground and airborne technology and shows clearly, in this case, the need for airborne FANS and ATN technology. (FANS being for Oceanic and ATN being for European operations in this instance).

Figure 2, meanwhile, visualizes the relationship of the Block Threads to the end goal of Efficient Flight Paths. It is further broken out in Table B, while one of the TBO Thread Modules, B0-TBO, is used as an example in Table C.

FIGURE 2: Relationship of the Block Threads to the End Goal of Efficient Flight Paths

Relationship of Block Threads to the End Goal of Efficient Flight Paths



ICAO document 9750 - Global Air Navigation Plan (GANP), includes a section on technology as it applies to ASBU blocks. The technology falling into one of 10 roadmaps is both airspace- and aircraft-centric. It is isolated out into domains and components of activity, potentially involving equipage for both (see Table D).

TABLE D: Domains and their Components Against a Roadmap Designation

Domains and their Components Against a Roadmap Designation


For Business and General Aviation aircraft, the Avionics domain is of specific interest. Each Roadmap has a format showing when the technology may be available that in turn drives the block module implementation date.

The Avionics domain provides its own indication of future equipage. From a general perspective we are now seeing the gradual blurring of Communication, Navigation and Surveillance (CNS) into one integrated technology. Data communication will drive navigation that itself, is under constant surveillance. Any change to route, navigation procedure, communication frequency, proximity traffic and weather will initiate a combined CNS response.

For pilots and ‘non-pilot autonomous operations’, these integrated CNS ‘commands’ will be seamless, reducing cockpit workload, while enabling greater focus on the ‘art and fun of flying’.

The equipment being installed today, designed to meet mandates and operating requirements, will not necessarily be replaced in the future. Equipment may be upgraded, via hardware and software, to maintain its capability. However, operators can anticipate the addition of equipment to facilitate a cockpit integration of 4D trajectory navigation, some time in the next decade (see Figure 3).

FIGURE 3: Roadmap #9
(Covering Avionics Navigation Enablers, Where New Equipment May Eventually be Required by Operators)

Avionics Navigation Enablers

Furthermore, legacy used aircraft operators may need to add ‘some box or other’ to continue operating their older avionics in the new ‘blurred CNS’ environment. 

It has to be understood that despite the daunting prospect of additional financial outlay, equipage is crucial to airspace performance. The greater number of aircraft that have capability, the more effective the performance improvement.

This, in turn, feeds into the integrated airspace performance and begins to have the quantitative effect of ‘the whole is greater than the sum of its parts’.

It should be noted that block modules of the Global Air Navigation Plan are inter-dependent, providing a complex set of possibilities that can impact the implementation of different modules, added to which are regional application variabilities to be considered.


For remote and oceanic regions, the burden of responsibility for global plans falls more on ICAO than in populated terrestrial locations. For these vast open areas there are equipage requirements that already bring together and blur the separate identities of the three CNS components.

Datalink Communication and the Automatic Dependent Surveillance (ADS-C) of Surveillance ensures safe and reliable flight within the PBN tracks of Navigation.

Purely from an aircraft equipage perspective, and specific to Required Navigation Performance (RNP), RNP 10 (RNAV 10 designation) and RNP 4, the requirements to operate are clearly defined by ICAO.

Oceanic and Remote RNP 10 and 4 requires that each aircraft monitors and alerts the performance and accuracy of its flight along a track. An accuracy that needs to be maintained 95% of the time.

International Civil Aviation Organization Airspace

50nm-RNP 10, and 30nm-RNP4, spacing between aircraft, along and aside each track, is permitted by the frequent use of communication and surveillance. Apart from cockpit monitoring, the use of datalink and ADS-C is mandatory for RNP.

Going forward, expect an incremental decrease in lateral and longitudinal separation and a greater deployment of these separations, along a greater number of Oceanic and Remote routes.

Anticipate an additional upgrade of existing Flight Management Systems, either of a hardware or software nature. Of course, you can also look forward to acquiring more operational approvals and more cockpit monitoring alerts.


Adequately covering ICAO, alone, is a mammoth task and we have barely skimmed the surface of its policy breadth and depth.

Of help to pilots may be the documents relating to regional plans such as Document 7030 (check latest edition) and ASBU Monitoring Reports, provided by ICAO-EUR States (2016) showing each EU member state’s adoption status of the various modules.

This can be very useful to aircraft operators intending to navigate across, and access into different member states and airspaces.

For operators who are NBAA members, there is a reliable resource available covering international operations. Additionally the Flight Services Bureau international OPSGROUP offers comprehensive coverage of operations.

This trilogy of airspace articles has brought together and summarized FAA-Eurocontrol and ICAO airspace plans that together govern, guide and control the equipment we use and the airspace in which we fly.

As a final tip, I suggest constant vigilance in monitoring the activity of all three agencies. Their requirements and timelines tend to shift and change as much as the weather impacting the performance improvements they are trying to implement.

That being said, there is no prospect of a delay in the ADS-B Out mandate, relating to FAA and Eurocontrol, at this time.

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