SESAR conducts world first 4D flight trial

The first initial four dimensional (i4D) trajectory flight successfully took place on February 10 two and a half years after active SESAR development work.
SESAR members Airbus, Eurocontrol, Honeywell, Indra, NORACON, and Thales contributed to the event which saw the Airbus A320 test aircraft taking off from Toulouse to Copenhagen and Stockholm, successfully validated the capability of the aircraft system to comply with time constraints elaborated and negotiated with ground ATC system through air ground datalink communication.
I-4D is a cornerstone of the SESAR programme as it is the first step towards more predictable flights.
“With this first I-4D trial flight under operational conditions, the SESAR members have proven that by working together in the framework of the SESAR programme real changes in the ATM domain are being brought about. Not only the aviation industry will benefit from optimised flights, but society as a whole”, says Patrick Ky, Executive Director of the SESAR Joint Undertaking.
Throughout the flight on an Airbus A320 test aircraft, the trajectory information containing current and predicted positions were exchanged with the concerned air navigation service providers and airports. This evolution is referred to as the 4-dimensional trajectory concept, or 4D, meaning a three-dimensional2 trajectory plus time.
Starting from Toulouse, the test aircraft flew through the Eurocontrol Maastricht Upper Area Control Centre (MUAC) airspace where the airborne and ground systems agreed on a first time constraint at a merging point close to Copenhagen airport. The flight then continued into Danish airspace to demonstrate an optimised descent to Copenhagen. After reaching the first merging point, the aircraft climbed to a cruise level from which it negotiated a second time constraint at a merging point close to Stockholm Arlanda Airport. The flight then descended into Swedish airspace in a fully optimised way to the second merging point and landed at Arlanda.
The trial successfully verified the automated 4D data exchange between the aircraft Flight Management System (FMS) and ground automation systems through datalink. It also aimed to validate how information is displayed to the controller and the pilot as well as the impact on their operations.
Initial 4D is a major step towards full 4D operations. In I-4D the capability of the aircraft FMS to provide very accurate trajectory predictions and execute a Required Time of Arrival (RTA) at a defined three dimensional waypoint can be exploited by both en-route controllers for demand/capacity balancing, metering of flows by applying a Controlled Time Over (CTO), or by TMA controllers sequencing for arrival management by applying a Controlled Time of Arrival (CTA).
The flight trial is part of a complete validation campaign in the framework of the SESAR Release process aiming at validating both technical and operational aspects. Other trials, using flight test aircraft but also a significant number of operational validations are planned within the context of the SESAR programme over the next two years. Provided the success of all validation exercises, I-4D should be implemented by the European industry as of 2018.
Marc Hamy, Airbus VP of SESAR and NextGen Deployment said: “This flight is a very important step towards the new air traffic management system we are looking for.
“It shows that most of the technologies required for integrating all the navigation and communication capabilities of the aircraft in the ATM systems are now available in Europe. But the decision for deploying these new technologies will depend on the benefits they can bring and this flight is also important to demonstrate all the improvements the airlines can expect from this new air traffic management system.”