OVERVIEW
The Rapid and Cost-Effective Rotorcraft (RACER) programme aims to demonstrate, in flight, that the compound rotorcraft configuration — by implementing and combining cutting-edge technologies from Clean Sky 2 — can unlock new mobility roles that neither conventional helicopters nor fixed wing aircraft can perform, sustainably, for operators and industry.
The project will ultimately demonstrate the capability to combine payload capacity; high manoeuvrability; agility in vertical flight (including capability to land on unprepared surfaces near obstacles and to load/unload personnel while hovering); long range; high cruise speed; low fuel consumption and emissions; low community noise impact; and high productivity for operators.
The RACER demonstrator, embodying new European compound rotorcraft architecture, is being designed, integrated and flight-tested with a first flight slated for 2022, targeting TRL6 at whole aircraft level in a basic configuration in 2023. The primary objectives are to demonstrate the reduction of CO2 and noise footprint, lower ownership costs, while improving speed, efficiency and productivity via the following research areas:
- Airframe structure and landing system: The RACER employs advanced composite and hybrid materials to minimise weight and optimise aerodynamic efficiency, enabled via an innovative box-wing/pusher propellers configuration.
- Lifting rotor and propellers: The RACER incorporates a low drag hub, pylon and nacelles, augmented with a 3D-optimised rotor blade design.
- Drivetrain and power plant: New drivetrain architecture and engine installation is being optimised via a new main gear box, propeller gear boxes, and supercritical shafts. Inflight demo of 'Eco-Mode' (cruising on one engine with the second engine idles) is planned via 'National Additional Activity' projects.
- On board energy, cabin and mission systems: Implementation of the more electrical rotorcraft concept is being optimised to minimise power off-takes from the engines and drive system.
- Flight control, guidance and navigation: Smart flight control is being deployed to enable additional degrees of freedom for optimal fuel economy and quieter flight.
OBJECTIVES
The RACER aims to validate the compound rotorcraft configuration, combining vertical flight capabilities with the faster flight characteristics of a fixed-wing aeroplane -- the best of both worlds. The aim is to prove — through design, construction and flight testing — increased payload capacity, high maneuverability, agility in vertical flight (including capability to land on unprepared surfaces), and the ability to load/unload or rescue jeopardised personnel while the rotorcraft hovers. Concurrently the objective is to improve range, increase cruise speed, lower fuel consumption and emissions, reduce community noise impact, and raise technical productivity for operators.
The demonstration configuration exploits a patented architecture consisting of a helicopter-like cabin and lifting main rotor augmented with an auxiliary fixed wing for high-speed flight, with two wingtip-mounted lateral rotors which act both as propulsive and anti-torque devices. The RACER also features an airplane-like tail, while the wing houses the transmission shafts which drive the lateral rotors. The Demonstrator also leverages technologies and lessons learned from its predecessor, the X3 experimental rotorcraft, complemented by mature and promising subsystems developed to TRL6 within Clean Sky. Demonstration activities are segmented into four multifunctional technology areas:
Technology Area 2A - RACER Flight Demonstrator Integration
This activity covers technical management of the programme and validation of the final results. The demonstrator design is developed and consolidated via feasibility, architecture, preliminary and detailed design phases. These are augmented with a configuration management process and a digital mock-up; studies of weight and balance; recurring cost estimation; interfaces management; aerodynamics and performance optimisation; digital and physical wind tunnel testing; piloted simulations for dynamics and noise; and testing with the flight environment for airworthiness, safety and maintenance. Once assembled, major efforts will be made to attain TRL6 for speed and mission completion time and overall effective aerodynamic lift over drag ratio, while meeting weight, noise, fuel-burn and CO2 targets. Activities in this work package include assembly of the flight demonstrator, integration and verification of subsystems, ground testing and the flight-test campaign.
Technology Area 2B - RACER Airframe Integration
This activity comprises the main fuselage structure from nose to intermediate rear fuselage, landing system, cabin and mission equipment, doors and wing and tail unit. Optimal materials, structural concepts, and construction techniques are employed to implement the new box wing/pusher props configuration. Compliance with high level technical objectives depends on airframe architecture and construction, especially for peak vehicle lift over drag ratio (aiming for effective lift improvement of over 20% relative to conventional helicopters), and minimal weight while prioritising use of eco-friendly materials and production methods. To integrate a fixed wing into the airframe configuration, the landing system will feature a lightweight, drag-mitigating retractable landing gear. To improve aerodynamics the fuselage is designed with a slim cross section, while, in the passenger cabin, efforts to improve comfort are instigated to minimise noise and vibration at high cruise. All of this is combined with the RACER’s functional potential for cabin accessibility and special operations in hover, such as rescue of endangered personnel using a hoist.
Technology Area 2C - RACER Dynamic Assembly Integration
Flight tests with the X3 experimental rotorcraft demonstrated that a conventional helicopter rotor can exhibit smooth behaviour and adequate lifting performance in high-speed flight — if lift is partially transferred onto the wing and propulsion is ensured through the lateral rotors. To leverage these advantages the RACER’s lifting rotor, lateral rotors, mechanical drive system, power plant, and actuation systems are highly integrated. This effort is underpinned through previous Clean Sky demonstrations in wind tunnel tests to achieve drag reduction solutions for helicopter main rotors, such as rotating and non-rotating fairings. Innovative fairing construction technologies allow rotor blade 3D rotational motion at the articulation while maintaining airflow tightness. An existing helicopter rotor will be re-used. However, design of the rotor blades deviates from those of conventional propellers by having to address two different functions: In hover and low speed conditions, yaw control and anti-torque balancing the lifting rotor torque; while in high-speed flight, the yaw control and anti-torque have to be in balance with the forward propulsive force. Output power from the RACER's engines is transferred to the main rotor and the lateral rotors via dedicated mechanisms and systems, while the configuration also incorporates numerous flight control actuators whose actions can be combined for better handling and performance.
Technology Area 2D - RACER On-board Systems Integration
Ideally, a compound rotorcraft should be as easy to operate as a conventional helicopter, experienced by the crew simply as a faster, more efficient mission performer, with the same crew workload. Hence, the RACER's avionics are adapted from existing hardware and software. The RACER's Electrical System builds upon the results of Clean Sky's Green Rotorcraft (GRC) and Systems for Green Operations (SGO), aiming at maturing and implementing a 270 VDC network on the flight demo. The advantages of high voltage, combined with lower weight electrical systems, are expected to benefit both the RACER as well as future conventional helicopters and aircraft. However, due to budget constraints, planning and technical issues, and to secure the first flight, the 270 VDC network is no longer part of the first flight configuration. Calls for Proposals have been issued to fly the high voltage network in a second phase with the ECO-MODE implementation on the RACER demonstrator.
Contributing Companies
Member Legal Name |
Company Type |
Country |
Role |
---|---|---|---|
Airbus Helicopters SAS |
IND |
FRANCE |
|
Airbus Helicopters Deutschland GmbH |
IND |
DE |
|
Airbus Helicopters Polska Sp z o.o. |
IND |
PL |
Support to the integrated design and development and manufacturing of the demonstrator. |
INSTITUTUL NATIONAL DE CERCETARI AEROSPATIALE ELIE CARAFOLI - I.N.C.A.S. SA |
RES |
RO |
Design and development of the RACER central fuselage airframe. |
ROMAERO |
IND |
RO |
Manufacturing and assemblying of the the RACER central fuselage airframe. |
GE AVIO Srl |
IND |
IT |
Design, development and testing of the RACER Main and lateral Gear boxes and shafts. |
AVIO Polska Sp.z.o.o |
IND |
PO |
Support to the design, development and testing of the RACER Main and lateral Gear boxes and shafts. |
Protom Group S.p.A. |
IND |
IT |
Design of the RACER actuator systems for mouvable surfaces. |
LATELEC |
IND |
FR |
Design and assembling of the RACER electrical and Mechanical harnesses. |
Latecoere |
IND |
FR |
Design and assembling of the RACER electrical and Mechanical harnesses. |
CENTRO ITALIANO RICERCHE AEROSPAZIALI SCPA |
RES |
IT |
Support to the design and testing of the RACER Landing Gears systems. |
Magnaghi Aeronautica Spa |
RES |
IT |
Design, manufacturing and testing of the RACER Landing Gears systems. |
Techno System Development srl |
SME |
IT |
Design of the control unit for the Electro-mechanical actuator of the RACER landing gear |
SIA CENTRE COMPOSITE |
RES |
LV |
Ultimate static and fatigue Testing of RACER Landing Gears system |
SIA AVIATEST LTD |
RES |
LV |
Ultimate static and fatigue Testing of RACER Landing Gears system |
M&S ENGINEERING SK SRO |
SME |
SK |
Support to the design of the RACER Landing Gears systems |
UMBRAGROUP SPA |
IND |
ITALY |
Design, manufacturing and testing of the RACER actuator systems for mouvable surfaces. |
CONTRIBUTIONS TO THE PROGRAM
AIRCRAFT TYPE TO BE ADDRESSED
- Clean Sky A/C: Compound Helicopter RACER - Ref: N/A
CONTRIBUTION TO THE HIGH LEVEL OBJECTIVES OF THE PROGRAM
- CO2 Reduction
- NOX Reduction
- Noise Reduction
- Competitiveness
- Mobility
TECHNOLOGY MATURATION
Technology Level - TRL |
|||
---|---|---|---|
Start TRL |
3 |
End TRL |
6 |