German Aerospace Congress 2009

The German Aerospace Congress is organised annually by DGLR, the German Society for Aeronautics and Astronautics. This year it took place at the Eurogress Conference Centre in Aachen, Germany, from September 8 to 10, 2009.

On the second day of the conference, DLR presented the AT-One paper on Virtual Block Control and Separation Bubbles. In contrast to the paper presented at ICNS 2009 in Arlington, this paper had a focus on evaluation of the concepts in cockpit simulator trials.

The conference sessions were generally set up with a broad range of topics so that there were not too many presentations directly focussing on ATM. Some of the presentations were mere descriptions of work approaches and used facilities, but they were nonetheless interesting. The sessions I attended described new approaches to avionics and control systems, especially for small private aircraft, knowledge management, simulator development, data analysis, and last but not least ATM.

A very interesting presentation from one of my AT-One colleagues described a revolutionary approach to controlling aircraft, referred to as sectorless ATM. In that scenario several tactical controllers share one giant airspace sector and control or rather guide a number of aircraft (between 3 to 8) through that sector. Although the concept still has some weaker points (controller communication, priority rules) it is an interesting starting point for innovative research in that area.

NARSIM Simulations on Virtual Block Control and Separation Bubbles

During the last two weeks NLR successfully carried out simulations on Virtual Block Control and the use of Separation Bubbles for Taxiway Conflict Alerting under low visibility conditions. The project was carried out by AT-One, the ATM research alliance between the Dutch and German Aerospace Research Institutes NLR and DLR, for Eurocontrol, the European Organisation for the Safety of Air Navigation.
The objective of the project was to evaluate operational improvements that would support air traffic controllers in more efficiently and more safely handling airport ground traffic when visibility conditions are so bad that pilots cannot avoid collisions by looking outside the cockpit (VIS-3). Furthermore, it was assumed that there were no additional means in the cockpit that would increase pilot situational awareness, such as moving map displays.
In an earlier workshop with controllers from several European airports it was concluded that a concept for Virtual Block Control in combination with a safety net for separation (Separation Bubbles) would most probably be the most effective improvement for ground control under the specified conditions.
In order to evaluate the new tools and the associated operational procedures, the NARSIM Tower simulation environment of NLR was equipped with prototype virtual stop bars on a ground traffic radar display and appropriate alerting services for stop bar and separation violations. Rotterdam Airport (EHRD) was chosen as the geographic location as it was considered to have an ideal layout for evaluating all operational challenges when using the new tools. Above that the Rotterdam set-up was already successfully used for controller training.



Two teams of controllers (from Rotterdam and Stockholm) took part in the evaluation sessions that assessed operational procedures and, in a later stage, traffic throughput together with automation trust, impact on mental workload, situational awareness, and general system usability. Results will be reported to Eurocontrol in a final report at the end of this year. It is expected that Eurocontrol will publish that report in early 2009.

EMMA2 Airport Simulations (Milan)

In July 2008 real-time simulations for a safety assessment of the Milan Malpensa tower controller working environment were carried out with the NARSIM-Tower validation platform at NLR Amsterdam as part of the EMMA project.

The objective of the simulations was to obtain results that support a safety assessment of the Italian prototype A-SMGCS components developed within the project timeframe.



The following analysis methods were applied during the experiments:
- Observation and Improved Operational Expert Elicitation
- Insertion of Hazards in the Simulations
- Measurement of Parameters for Risk Uncertainty Reduction

Results of the real-time experiments will become available as part of the EMMA2 Validation Analysis Report at the beginning of 2009.

What is A-SMGCS?

A-SMGCS stands for Advanced Surface Movement Guidance and Control Systems and is a modular system with the aim to maintain the declared surface movement rate at an airport under all weather conditions within the aerodrome visibility operational level while maintaining the required level of safety.

Eurocontrol defined four different implementation levels (I to IV) for such a system and separated system functionality into the four categories surveillance, control, routing, and guidance. Implementation is expected to follow a stepwise approach addressing each of these categories in more or less the order above.

Currently the European Commission funded projects EMMA and EMMA2 look into the details of possible implementations at three different airports for A-SMGCS levels I/II and III/IV respectively. The airports involved are Prague, Milan-Malpensa, and Toulouse. Additionally, there are surveillance measurement campaigns at Paris Charles-de-Gaulle Airport.

NLR is part of both projects and also carries out additional work for Eurocontrol investigating advanced procedures for the use of A-SMGCS Level I (airport surveillance enhanced by multilateration) during low visibility conditions.