How to now embark on future Aeronautical Information Management

By Dr. Günter Hellstern and Ulrich Kaage, COMSOFT, Germany

Integrated Aeronautical Information Management (AIM) is a buzz word that addresses the demanding needs of tomorrow's air traffic and flight management for consistent and up-to-date data. It is obvious that only AIM-solutions based on latest international standards will be made ready for the future, and any proprietary approach will lead to a dead end. Two possible migration scenarios, from conventional Aeronautical Information Services (AIS) to AIM, can be identified and are discussed in this article according to key criteria like risk, costs, smoothness of transition, and long-term vendor dependency.

Aeronautical Information Services

For many years historical and technological reasons constituted two clearly separated areas of AIS. States are required to publish primarily paper-based documents like Aeronautical Information Publications (AIP) and aeronautical charts. These documents form the static data part of the AIS. In addition to these slow to distribute paper based documents, aeronautical messages like NOTAM are used to supply facts at short notice. This message-oriented data exchange makes up the dynamic part of AIS which can be accomplished by meteorological information.

A number of offices as well as a number of distribution channels are required in order to produce, manage, and disseminate the information that is finally used by airlines and pilots during all phases of a flight in order to safely guide air traffic. (Figure 1).
Since information is distributed over several separate databases and often even managed by different offices or departments, it is a tedious and costly task to make data consistently available all the time. Increasing air traffic, restricted air space and necessary cost savings, however, make more efficient data management compulsory.

Integrating Aeronautical Information Services

As a first step we can ensure data consistency by centralising the data management. The key approach is to store all relevant data in one single database which will then be used by various specialised applications as depicted in Figure 2.

As an example, COMSOFT recently supplied and set-up a country-wide AIS network for Vietnam's national air navigation service provider VANSCORP, including 22 locations with one master database and three replicated sub-site databases. By consequently using open standards, COMSOFT could build a best of breed AIS, which makes use of its own applications as well as of such from other market leader vendors.

Thus VANSCORP can centrally manage the data for NOTAM, OPMET/BUFR/GRIB, electronic AIP, search and rescue, documentation services, and aeronautical charting. A supplementary subsystem for integrated briefing and flight-planning makes use of this data, and an internet-based web portal provides services to airlines and pilots.

As the majority of VANSCORP's existing AIS data was based on paper, COMSOFT laid out a comprehensive migration plan to digitalize the data in a safe manner.

Fully automated and integrated AIS implementations like this are a major step in the AIM direction as they ensure a tremendous increase in quality and accuracy of data compared to distributed AIS. However, static data and their dynamic updates are still handled separately. It is left up to airlines and pilots to re-establish this link and to put together a puzzle of different pieces, which are distributed through separate media channels and received at different times. It is obvious that this cognitive process is labour-intensive and error-prone, and is no longer befitting of the information era in which we live. 

Recent, accurate, and most of all digitally machine-readable data would enable airlines to optimise their flights and make travelling more economical. Significant advantages would be

• fewer delays
• reduced fuel consumption, thus reduced operational costs and less carbon-dioxide footprint
• increased in-flight situation awareness and therefore increased flight safety

Data Fusion in AIM

The findings of the previous sections are in fact part of an ongoing discussion in the aeronautical community. EUROCONTROL and FAA have jointly defined a comprehensive and holistic data model to tackle the issue of currently inhomogeneous and not fully machine-readable data. It is named Aeronautical Information Exchange Model Version 5 (AIXM 5) and is in line with a long history of successful AIXM versions.

AIXM 5 is the first AIXM version that enables data fusion, the combination of static and dynamic data persists even when passing system boundaries. Therefore AIXM 5 is the first of the AIXM versions that enables true AIM. The most outstanding differences and benefits compared to its predecessor AIXM 4.5 are:

• A temporality model integrates dynamic data (NOTAM, Weather, etc.) with static data
• It is based on OGC (Open Geospatial Consortium) and ISO standards
• It is extensible, easily allowing the addition of further domain specific information

When designing AIXM 5 the goal was to pave the way for a revolutionarily enhanced AIM concept but not to be backward compatible to data structures of existing AIS implementations. This entails the unspoken truth that existing AIS equipment cannot be upgraded to AIXM 5 as easily as  was the case when moving from AIXM 3.3 to AIXM 4.5. The main reasons are:

• Existing vendor-proprietary database models and extensions are not compatible with AIXM 5
• The advanced features of AIXM 5 also require latest database concepts and implementation technology
• Existing applications are linked with earlier AIXM data structures and need to be changed to deal with AIXM 5 data

NOTAM go Digital

The new capabilities that come with the fusion of static and dynamic data will fundamentally enhance the handling of NOTAM. Digital NOTAM defined in AIXM 5 can be interpreted by automated systems in the same way as static data, and this will foster the development of completely new and advanced end-user applications. For instance, new generations of Electronic Flight Bags will immediately show updated NOTAM information in-flight, improving the pilot's situational awareness. On-board equipment will be able to interpret short notice information like airspace closures, runway closures and shortenings and the like. Flight management systems will also be able to take this information into account and assist pilots in carrying out the right procedure.

While it is not possible to fully automatically convert conventional NOTAM into Digital NOTAM, the reverse is a straight-forward procedure. Therefore, national organisations can internally switch to Digital NOTAM and provide the necessary backward compatibility for remote partners that are still connected to the conventional ICAO NOTAM distribution network.

Migration to AIM

The instant advantages of an AIXM 5 based AIM have been made obvious but the question arises how to best embark on the future. As stated earlier, moving to AIXM 5 is not just a small software update but needs to be carefully planned. One should consider the following criteria

• Costs for initial purchasing and maintenance
• Risk for operational usability and safety
• Smoothness of transition
• Long-term dependency on vendors

Two completely different migration scenarios can be identified which are named "Hybrid" and "Modular" Migration in the following.

Hybrid Migration:

With this approach both the database and the applications are migrated to AIXM 5 on a step-by-step basis. Applications and database are kept in hybrid state and they deal with the old and the new data model at the same time. For instance, in a first straight-forward step only the part of AIXM 5 dealing with obstacles will be implemented, all other data will stay in the original format. A number of further -and more complex - steps are required until all data is fully migrated to AIXM 5.

With each new update all applications are updated synchronously, e.g. when the obstacle model is migrated to AIXM 5 then every application dealing with obstacles (AIP, Charting, NOTAM) is changed. The full advantage of AIXM 5, in particular the desired combination of Digital NOTAM and static data, can be yielded after some years when migration is completed.

The hybrid approach entails the following disadvantages

• It uses two separate data models in parallel and therefore has to be considered as a step back in reaching the goal of maintaining only one central aeronautical database
  Maintenance effort is high because labour-intensive activities arise for each database and application update
• Performance figures are most likely to drop in case advanced AIXM 5 features are implemented as piggyback to conventional databases
• There is a safety risk to data inconsistency when iteratively changing data models
  Possibly several teams of staff need to be trained after each software update

The list of disadvantages speaks for itself and has little prospect for a risk-free migration of data and services. The question is now why many AIS system vendors propose the hybrid migration, and the answer is simple and obvious: The upfront investment for this approach is much lower for the vendor. As a side effect customers are completely tied to the vendor because during the long-lasting migration phase there is no real compatibility to system components of other vendors.

Modular Migration:

Another approach is to accept that AIXM 5 is a groundbreaking new standard and to consider a full AIXM 5 database implementation as the base of a strategic system re-design. Application modules can either apply AIXM 5 or older standards. An online conversion module enables interfacing with system components that are still based on AIXM 3.3 or 4.5, ARINC, or even proprietary data exchange formats.

The modular concept opens up the utmost flexible migration scenario with a significant number of advantages:

• Low safety risk because all operationally relevant data can be imported into AIXM 5 in one step guaranteeing consistency and completeness.
• The AIXM 5 data management front-end allows the user to extend the initial data thus taking full advantage of the rich feature set from the very beginning. All imported data is stored in a single data model and has already been prepared for interaction with Digital NOTAM.
• Maintenance is low because applications only need a single update. These updates can be performed on an individual schedule for each application without interfering with other parts of the system.

The database has been designed in accordance with the demands of AIXM 5, and all performance figures are known from the very beginning.
The modular approach allows its users to define the following smooth exemplary migration scenario:

1. Database update to AIXM 5
2. electronic AIP application update
3. Aeronautical Charting application update
4. NOTAM office application update to switch to Digital NOTAM

Costs and risk are low for the user because the migration is transparent, and unlike with the hybrid migration, hidden costs can be avoided. In particular, the customer is not tied to a single vendor but can choose from a number of products because AIXM 5 defines a well standardized data exchange format. Many risks have been shifted from the operational phase to the vendor's initial system development and have been tackled there. COMSOFT is the only AIM manufacturer who has taken this risk for the benefit of the customers and has already implemented this promising but demanding concept. Another benefit of COMSOFT's modern design based on Service Oriented Architecture (SOA) principles is that workflows can be adjusted swiftly to the user's needs.

Conclusion

COMSOFT's design concept facilitates a migration scenario for AIS data and services that enables organisations to approach AIM at a very low risk and in a smooth manner. Total cost of ownership can be fully assessed in advance. The comprehensive AIXM 5 implementation means experiencing the advantages of AIXM 5 from the beginning.

Moreover the proposed solution applies modern system architecture principles while being fully backwards compatible and unmatched in terms of interoperability and extendibility.

Convinced by this strategy, European organisations have already embarked on the COMSOFT migration path: A fully featured database implementing AIXM 5.1 with an electronic AIP application and interfacing to the European AIS Database (EAD) will be commissioned by the end of 2009 in Estonia allowing users to benefit from the first operational AIM worldwide.