Flying in 4D

We spoke with Pascal Combe, SESAR Project Manager at Thales, to understand the role of I-4D in modern air traffic management and how Thales contributes to its development.

Pascal, what does the I-4D concept consist of?

The I-4D concept is a key step in the modernisation of European air traffic management. It allows aircraft to synchronise their flight trajectory in four dimensions latitude, longitude, altitude, and time through real-time communication with Air Navigation Service Providers (ANSPs). By integrating a precise time component, flights become more predictable, improving efficiency and reducing environmental impact.

How does I-4D improve air traffic management?

I-4D enhances air traffic predictability by pre-defining flight paths with greater accuracy. This results in improved arrival sequences, reduced airspace congestion, and optimised fuel consumption. Pilots and controllers benefit from reduced workload, as aircraft follow predefined paths with minimal intervention, enhancing overall safety.

What differentiates I-4D from traditional 4D trajectory management?

The ultimate goal is full 4D trajectory management from takeoff to landing, including airport surface operations. However, this requires significant infrastructure upgrades. I-4D serves as an intermediate step, focusing on merging aircraft at congested areas through precise time constraints, known as the Controlled Time of Arrival (CTA). This improves air traffic flow without requiring full 4D capability.

How does I-4D impact onboard avionics?

The Flight Management System (FMS) plays a crucial role in I-4D operations. Thales has developed an advanced FMS capable of transmitting a complete 4D trajectory including up to 128 waypoints via Automatic Dependent Surveillance – Contract (ADS-C). This system also receives air traffic control clearances in real-time, streamlining communication between pilots and controllers. Additionally, new algorithms ensure Required Time of Arrival (RTA) precision within 10 seconds, displayed directly on cockpit instruments to assist pilots in maintaining their time constraints.

What were the outcomes of the first I-4D trials?

In 2012, Thales participated in the first live demonstration of I-4D, proving its potential for improving air traffic predictability. A second trial in 2014 successfully validated air-ground data exchange, demonstrating that aircraft could precisely adhere to time constraints during en-route and approach phases. These trials confirmed the feasibility of large-scale implementation and set the stage for further advancements.

What are the next steps for I-4D implementation?

SESAR has moved into a new phase with SESAR 2020, which will integrate I-4D on a larger scale. By 2019, major demonstrations took place under real airline conditions, and 250 aircraft are expected to be equipped with I-4D capabilities by 2022. This marks a significant step towards a fully connected and efficient air traffic management system.

I-4D trajectory management is a key step toward optimizing global air traffic. By enhancing predictability and reducing congestion, this technology represents the future of air navigation. Pascal Combe highlights how Thales is driving this transformation.