CORDIS - EU research results

GNSS-based ATM for Rotorcraft to Decrease Emissions and Noise

Final Report Summary - GARDEN (GNSS-based ATM for Rotorcraft to Decrease Emissions and Noise)

Executive Summary:
The GARDEN project - GNSS-based ATM for Rotorcraft to Decrease Emissions and Noise - supported the definition of new flight profiles
for rotorcraft to reduce the noise footprint. Concrete milestones have been implemented to address various types of operational and regulatory issues that rotorcraft operators have to tackle. The GARDEN project brought state-of-the-art expertise in Air Traffic Management to meet the CleanSky JU objectives. A major Air Navigation Service Provider, a National Regulator, two specialised engineering companies and, procedure designers, permitted to address the following main challenges:
• The definition of tailored procedures and low-level routes for rotorcraft,
• The safety and environmental assessment of the new procedures,
• The promotion of these new types of operations through the performance of demonstrations,
• The support of GARDEN experts to the GRC-5 TP3 (Environment-Friendly Flight Path Project).

The main benefits were related to safety improvement for rotorcraft operations combined with noise minimisation.
Noise minimisation of IFR procedures is the main challenge tackled by the GARDEN project. Indeed, rotorcraft IFR procedures that are considered are related to departures, approaches and low level routes conducted close to the ground and consequently, could disturb local residents if no precaution taken. GARDEN gives high priority in reducing noise footprint by designing flexible rotorcraft specific IFR procedures using steep slope flight profiles and avoiding most noise sensitive urban areas.

Project Context and Objectives:
State of the art – Background
Air traffic is expected to grow continuously in the next decades. Reducing the environmental footprint of aviation has therefore become a major challenge for industry stakeholders and including for rotorcraft operators. Working towards greener skies, the European Commission has created jointly with the aviation industry the Clean Sky Joint Undertaking. Its objective is to develop technologies that mitigate the impact of air transport on the environment (reduction of aircraft external noise, emissions and fuel consumption).
One of the initiatives launched by CleanSky JU in this perspective is the GARDEN project (GNSS-based ATM for Rotorcraft to DEcrease Noise). The project consists in developing new IFR flight procedures based on the use of GNSS and enabling rotorcraft to reach busy airports fully independently of the airplane traffic operating from or to active runways.
For this two-year project CleanSky JU has selected a consortium led by Egis Avia and also formed by the French air navigation service provider (DGAC/DSNA&DTA), Pildo Consulting and CGX AERO. The consortium will provide support in the design and implementation of GNSS-SBAS IFR procedures for rotorcraft.

The objectives that have been achieved in the frame of this project were to:
• Identify and analyse the existing regulation for helicopter operations based on GNSS;
• Define new Instrument Flight Rules (IFR) operations for rotorcraft relying on GNSS guidance with the related safety assessment;
• Define generic IFR procedures minimising noise footprint and allowing rotorcraft to reach or depart from airports independently from the fixed-wing aircraft traffic (called SNI – Simultaneous Non Interfering procedures);
• Perform in-flight demonstrations at a medium airport with commercial traffic (Toulouse) and at a heliport in a constraining environment (La Seu d’Urgell);
• Provide expert support to CleanSky Environment-Friendly Flight Path (EFFP) project (GRC-5 TP3) for developing and testing low noise rotorcraft-specific IFR procedures.

Project Results:
Description of work
The GARDEN project is structured in five main Work Packages (WPs):
• WP1 – Regulations Baseline: this first activity encompasses the inventory of existing regulation criteria applicable to rotorcraft GNSS IFR procedures and SNI operations.
• WP2 – Generic Green Procedures: this second part of the activities consists in the definition of guidance material for designing IFR low noise procedures (approaches, departures and low level routes) for rotorcraft operations. IFR procedures design is based on noise optimised flight paths provided by GRC-5. A safety analysis for the use of these procedures in a Simultaneous Non Interfering context is conducted in parallel.
• WP3 – Procedure Implementation and Validation: this third part of the activities consists to use the generic procedure guidelines (WP2 outputs) to design and implement low noise IFR procedures at two specific sites. The first site is Toulouse airport to assess Simultaneous Non Interfering (SNI) Rotorcraft – Aircraft operations. The second site will be defined to consider specific constraints related to urban and mountainous areas. In both cases, the focus is made on environmental impact in terms of noise footprint minimisation. An implementation of Low level IFR route in vicinity of urban areas such as for the purpose of medical transport is also proposed.
• WP4 – Demonstrations: this part of the activities consists to achieve a concrete implementation of low noise IFR procedures through in-flight demonstrations. These In-flight demonstrations will be conducted by Airbus Helicopters at the previously mentioned test sites. For each site, the noise footprint will be assessed by GRC-5 using a noise prediction tool. The real environmental efficiency of green rotorcraft procedures will be validated after the flight demonstrations.
• WP5 – Disseminations: In addition to the information exchanges with GRC-5 TP3, the regulation analysis and design criteria for low noise IFR rotorcraft procedures proposed by GARDEN will be disseminated to relevant rulemaking bodies such as EASA and ICAO.

WP1 – Regulations Baseline
Regulatory inventory and proposals (WP1) has been completed since mid-2011. The 1st deliverable document aims at identifying and analysing applicable air navigation regulations based on the existing and on-going PBN (Performance Based Navigation) procedures relying on GNSS for rotorcraft specific IFR operations. The 2nd deliverable document identifies and analyses the existing criteria for SNI operations between fixed-wing aircraft and defines new criteria for SNI operations between rotorcraft and airplanes.
CleanSky JU agreed to provide these documents as an input to ICAO IFPP (Instrument Flight Procedure Panel) group and also to SESAR.
The regulatory work has been presented by Egis Avia and Airbus Helicopters (formerly Eurocopter) during the 5th EASA rotorcraft symposium held on the 7th and 8th of December 2011 in Cologne.
WP2 – Generic Green Procedures
WP2 dealing with generic low noise IFR procedures is completed: related activity is divided into two parts: the first part permits to define guidance materials for designing rotorcraft IFR Simultaneous Non Interfering (SNI) approaches and departures minimising noise disturbance and also associated low level routes. This has been finalized in April 2012. The second part is related to safety activities and is conducted following a three step approach:
• Step 1: Firstly a safety analysis on green rotorcraft operations has been delivered in September 2012. This document is the first step of the development of a generic safety analysis of Simultaneous Non Interfering (SNI) operations. As identified in the Criteria for Simultaneous Non Interfering (SNI) Aircraft-Rotorcraft operations document (D1-2 deliverable), SNI operations will be preferably based on Steep LPV approach and PinS LPV approach concepts, or a combination of both. The objective of this document is thus to perform the safety assessment of the implementation of the following green rotorcraft operations:
o PinS LPV approaches;
o Steep LPV approaches;
o Airbus Helicopters concept based on specific optimized on-board trajectory computation.
In this first document, safety related to the concepts themselves has firstly been addressed.
• Step 2: Before completion of the safety assessment of the SNI operations, it was then important to define the operational model of Simultaneous Non Interfering (SNI) aircraft-rotorcraft operations based on GNSS (D2-5 deliverable), which will serve as an input for the safety analysis of these operations.
• Step 3: The impact of the implementation of such procedures on the air traffic system has been addressed through the safety assessment of the SNI operations (D2-6 deliverable).
Safety activities have been finalised mid-2013.
WP3 – Procedure Implementation and Validation
After the finalisation of the safety activities presented above, 2014 was then dedicated to the detailed design, implementation and validation of low noise aircraft-rotorcraft IFR procedures based on GNSS. The first step was to confirm the sites selected for the demonstrations. Toulouse Blagnac airport, being a medium-size airport permitting to demonstrate the SNI concept, was selected. Procedure design was done based on the outputs of the second work package. Noise optimisation of the procedures has also been achieved by taking care of the noise footprint predictions performed by Airbus Helicopters in the frame of GRC-5.
WP4 – Demonstrations
In-flight demonstrations were prepared as a joint activity between GARDEN and GRC-5 TP3 (Airbus Helicopters). In the frame of GRC-5 TP3, Airbus Helicopters performed in June 2013 acoustic measurements in flight in order to assess the noise reduction that can be achieved with noise optimised flight paths and to validate the FMS guidance modes. In the meantime, coordination with local actors was necessary to ensure that flights can be conducted in operational conditions (i.e. integrated in real traffic conditions) in order to validate the concepts.
On May 5-6 2015, in collaboration with Airbus-Helicopters, those IFR low noise SNI procedures were successfully demonstrated in flight with a H175 helicopter, using EGNOS guidance, at Toulouse-Blagnac airport in real traffic conditions.
WP5 – Disseminations
GARDEN outcomes (regulatory and safety) were presented in the frame of the 5th and 7th EASA Rotorcraft Symposium in December 2013 & 2014.
A focus on the flight demonstrations has been made during the last Helitech symposium organised in London, in October 2015.
Finally, a User Forum has been organised in Toulouse (la Cité de l'Espace) on Nov. 5, 2015. This User Forum presented the work performed in GARDEN & CARE projects, the links with the “Environment-friendly flight paths” project (GRC-5) of the Green Rotorcraft Integrated Technology Demonstrator (GRC-ITD) CleanSky overall activities and the main outcomes. Many Stakeholders (ANSPs, rotorcraft manufacturers, on-board equipment manufacturers, operators, regulators...) attended the event.

Potential Impact:
Expected benefits
Low noise flight operations
These new trajectories are of major interest as they allow rotorcraft to avoid flying over noise sensitive urban areas, especially thanks to the use of high-precision GNSS-SBAS guidance for approaches and departures. This is particularly important for Final Approach and Take-Off areas (FATOs) located within urban areas.
Low noise procedures are a major green leap forward and they increasingly capture the interest of airports and operators as an effective solution for noise abatement in residential areas overflown by rotorcraft.

Improved safety
GNSS-SBAS guidance also enhances both the precision and the performance of rotorcraft navigation. In particular, these new GNSS-based IFR procedures enable rotorcraft to operate under IFR in challenging environments such as mountainous areas and to fly safely steep approaches to airports or heliports that are difficult to access or located in densely populated areas. This is particularly important for
medical air transport to city hospitals or for helicopter operations in the vicinity of airports without interfering with the surrounding fixed-wing aircraft traffic.

List of Websites:
GRC-5 TP3 Topic Manager: Philippe Rollet
# Airbus - Helicopters
Aéroport International Marseille Provence
13725 Marignane Cedex - France
# +33 (0)4 42 85 69 20

Project Manager: Alexa Hourclats
# Egis Avia
4 bis rue Paul Mesplé
BP 20603 - 31106 Toulouse Cedex 1 - France
# +33 (0)5 62 24 56 33