A SESAR validation exercise has shown that advanced approach procedures using vertical guidance (APV) provide flight crew and air traffic controllers with good situational awareness and have the potential to increase predictability of incoming flights to an airport. The procedures aim to enable vertically guided approaches to runways not equipped with standard instrument landing aids.

Carried out at Turin Airport on 20 and 21 May 2014, the validation is the final phase of a project dedicated to validating advanced APV procedures, definition and demonstration within the SESAR Research and Innovation (R&I) Programme. The advanced APV concept was the result of two different project consortia: The first project, took an operational focus and included AENA, AIRBUS, ENAV, Eurocontrol, NATS, NORACON and Thales and  the second project, focused on the aircraft side and included Alenia Aermacchi, CHC/EHA, Dassault Aviation, DGAC, EBAA, IAOPA, IATA, IFATCA and NOVAIR.Developed by ENAV Airspace Design Department, the procedure uses localiser performance with vertical guidance (LPV) minima (GPS and EGNOS-based) and features conceptual elements, such as Continuous Descent Operation (CDO) and a curved intermediate segment with last “Radius to Fix (RF)” leg linked to the final approach. In addition, an Advanced APV avionics solution has been developed by Alenia Aermacchi and Thales for the Alenia Regional Aircraft research simulator and by Thales for the ATR 42/72-600.

The advanced LPV procedure was successfully validated in two steps:

• A ground validation led by Alenia Aermacchi and carried out at its Regional Aircraft research simulator;
• A flight validation led by Alenia Aermacchi in collaboration with ATR and ENAV staff members and carried by means of an ATR42-600 aircraft.

Regarding the flight tests, the crew conducted nine approaches in order to test three different vertical profiles. These were all safely performed during normal daily air traffic operations, continuously monitored by ENAV’s dedicated Air Traffic Controllers (ATCOs) in Turin Airport.

The exercise focused on the feasibility of operational implementation of such a solution, from both ground and air segments perspective. The assessment looked at the lifecycle of an approach operation, starting from procedure design and coding issues up to avionics behavior and operational procedures (crew and controller workload, situational awareness, etc.).

The live trial showed that advanced APV procedures worked in the selected scenarios, shedding light on some of the expected benefits. Initial feedback from crew members and controllers was very positive. Pilots were able to fly stabilised approaches, with both three and four degree glide path angles, in clean configuration (saving fuel and reducing the noise impact) keeping a good situational awareness with a moderate workload. Air traffic controllers were able to manage traffic with workload and situational awareness comparable to the current situation.

Furthermore, staff participating in the validation provided advice to further optimise the procedure’s operational impact (e.g. additional Initial Approach Fix/Segment and Holding Pattern), highlighting the advantage that the advanced APV procedure allows Instrument Approach Operations on runways, where no standard (conventional and/or RNAV) approach operations are possible due to operational constraints (particularly concerning its demanding terrain).

The validation exercise contributes to SESAR’s overall goals of increasing flight predictability while at the same time guaranteeing the highest level of safety of operations.

The post-analysis activity is still in progress. Final and more exhaustive results will be communicated by the SESAR Joint Undertaking in the coming months.