From research to operations: Zurich Airport’s early roll-out of a SESAR solution for smarter arrivals

How can airports move promising research solutions into real operations before full standardisation and maturity are reached? Zurich Airport, together with SWISS, Skyguide and technology partners, is providing an answer through the early operational use of the target time management system (TTMS) developed in the HARMONIC project.

TTMS 1: ZRH Arrival RWY14

In this interview, Mike Brügger, Senior Project Leader for Performance & Systems Development at Zurich Airport, explains why it chose to test TTMS in a live operational environment, the challenges it aimed to address, and the factors that enabled a safe and effective deployment. The airport also shares the lessons learned from moving beyond simulations and research validation towards sustained operational use - offering valuable insights for other airports looking to accelerate the uptake of SESAR Solutions.

What motivated Zurich Airport Ltd and SWISS to start implementing the target time management system (TTMS) from the HARMONIC project before the solution was fully finalised within SESAR, rather than waiting for full standardisation?

Zurich Airport, SWISS and Skyguide decided to conduct early operational trials to validate the actual value of TTMS under real conditions rather than relying solely on simulations. The aim was to start with a focused minimum viable product and improve it step by step.

TTMS primarily distributes delay resulting from existing capacity constraints more intelligently across flights. This keeps the operational risk relatively low while offering significant potential to use the available capacity more effectively.

The approach was supported by a strong level of trust between the partners and a shared understanding that early operational learning was more valuable than waiting for full standardisation, provided the trials were conducted safely, transparently and under controlled conditions.

Which specific operational challenges at Zurich (e.g. hub complexity, peak summer congestion, delay propagation) made TTMS particularly relevant and worth prioritising at an early stage?

At Zurich Airport, runway capacity is frequently constrained by the challenging crossing runway layout and local weather conditions, such as wind and reduced visibility.

As a result, Zurich Airport regularly faces air traffic flow and capacity management (ATFCM) arrival regulations, which have a direct impact on overall punctuality and operational predictability. For SWISS as the main hub carrier, arrival punctuality is especially critical, as inbound delays can directly affect aircraft rotations, passenger connections and departure punctuality.

TTMS therefore offered a promising way to manage constrained arrival capacity more intelligently by considering operational priorities from the airlines, the airport operator and air navigation service provider (ANSP).

TTMS 2: TTMS OPS Trial-Results

To what extent were Zurich Airport Ltd, SWISS, and partners such as Zühlke Group directly involved in the SESAR research activities behind HARMONIC and TTMS, and how did that involvement influence the design or usability of the solution?

Zurich Airport contributed to the airport operational perspective, ensured integration into the airport operations plan (AOP), and provided the required cloud infrastructure. SWISS defined airline priorities, provided cost-of-delay analyses, and assessed the business impact of different TTA scenarios.

Skyguide contributed to the air traffic management (ATM) perspective and ensured safe live trial operations, compatibility with ATC procedures, ATFCM processes and operational safety requirements. Its continuous involvement was essential for operational acceptance.

Zühlke supported the technical development and integration, including the B2B connection for data exchange with the Network Manager. JKU and Frequentis contributed to the prioritisation and optimisation logic forming the core of the TTMS optimiser.

Overall, the close collaboration ensured that TTMS was developed as an operationally usable tool rather than a purely theoretical research concept.

What were the key enablers that allowed TTMS (including both the optimisation algorithm and the privacy engine) to be integrated into the AOP) so quickly and effectively in an operational environment?

A key enabler was the strong collaboration between Zurich Airport, SWISS, Skyguide and Zühlke, with all partners sharing the common objective of testing TTMS in a realistic operational environment while keeping the implementation focused, safe and manageable.

Skyguide's role was particularly important, as the live trial was closely linked to real arrival regulation processes. Their expertise ensured that the TTMS outputs were assessed from an operational perspective, to be consistent and compatible with existing regulation management framework. This was essential for moving from a research concept to an operational trial.

To assure operational resilience, clear processes and fallback options were defined, allowing Skyguide and the operational partners to revert to a conventional regulation at any time if required. This helped build trust among the operational units and supported the safe early deployment of TTMS.

TTMS 3: TTMS Operational Concept

Based on the early operational use, what have been the most tangible benefits so far in terms of predictability, delay reduction, and capacity management - and what lessons would you share with other airports considering early deployment of SESAR solutions such as those developed under HARMONIC?

During the eight-week live trial at Zurich Airport in May-June 2025, TTMS was applied in 51 regulations covering 3,372 flights, including 2,078 SWISS flights. The reported benefits are based on a comparison between the actual TTMS results and a simulated CASA baseline. The results were promising, with SWISS arrival punctuality improving by 20.2% and heavy delays of more than 30 minutes being reduced by 23.5%. Airport-wide, total arrival delay minutes decreased by 11% and missed connections by 14%, with no systematic disadvantage for non-participating airlines.

A subsequent three-month trial from October to December 2025 confirmed the positive outcomes under varying traffic conditions. In early 2026, a year-long operational trial was launched, marking the transition from experimental deployment to sustained operational use.

However on the ANSP side, the ATFM delays are increased with TTMS usage and it is a key subject to be addressed before the full operationalisation of the system.

Beyond the quantitative benefits, TTMS improved transparency and predictability in the management of local arrival regulations. Skyguide's involvement was essential to assess the solution from an ATC and regulation management perspective.

The key lesson for other airports is to start pragmatically, reduce complexity and involve all operational partners early. A focused minimum viable product, combined with clear fallback procedures, can create value early while maintaining operational safety and trust.

More about HARMONIC

More about the Zurich trials