MRH-90

The MRH-90 is the Australian version of the NH90 TTH (Tactical Transport Helicopter) and was selected to fulfill Project AIR9000 Phase 6 - Sea King replacement.

The concept of the NH90 Programme originates from studies conducted by the NATO Industrial Advisory Group "NIAG SG14" and was born out of a need for an innovative Naval/Tactical Helicopter to face-up the military scenario of the next decades.

After agreement on the financial participation of industry, the Governments of France, Germany, Italy and The Netherlands signed the MoU in December 1990 for the full development. The Four Participating Governments constituted NAHEMO (NATO Helicopter Management Organisation) comprising the Steering Committee and NAHEMA (NATO Helicopter Management Agency).

NAHEMA represents the four Governments, controls the overall execution of the programme, is responsible for the qualification of the NH90 weapon system, and is the interface to the contractor for the negotiation, placing and administration of the Prime Contracts.

The four companies sharing the Design and Development of the NH90 Programme (AGUSTA, EUROCOPTER, EUROCOPTER DEUTSCHLAND and FOKKER) signed an Intercompany Agreement in March 1992 and established a joint venture NH Industries, to ensure the industrial programme management.

The MRH-90's main rotor features four composite blades and a titanium main rotor hub with elastomeric bearings. Anti-torque function is provided through a high positioned tail rotor that is mechanically linked to the main transmission.

Power is initially supplied by an APU for ground operations prior to starting the two Rolls-Royce/Turbomeca RRTM322-01/9 turbo-shaft engines. Each engine is positioned in separate bays behind the Main Gear Box and includes a FADEC control. All dynamic systems assure a 30 minute dry run capability.

The MRH-90 has a composite, crashworthy fuselage with a constant cross-section central fuselage. The forward fuselage contains the cockpit with two crashworthy seats for Pilot (RH) and Co-pilot (LH) and an optional foldable crashworthy jump seat for an additional crew-member. Two large emergency exits for the crew are provided.

The centre fuselage offers a spacious, unobstructed cabin with a sliding door on each side. The cabin allows the installation of up to 20 troop seats, and, alternatively, the installation of up to 12 stretchers. Emergency windows on each side are provided.

The MRH-90's significant crashworthiness capability is based on MIL-STD-1290A. This is provided by the sum of sequential and progressive intervention of several items: the shock absorbing Landing Gear, the crushable structure bottom and the crashworthy crew seats together with the crushable fuel system, the retention of the high mass components and the controlled deformation structure maintaining the vital space.

The MRH-90 fits a tricycle type retractable landing gear consisting in two single type main wheels installed in the centre fuselage and a twin steering wheel in the forward fuselage.

The Flight Control System (FCS) of the MRH-90 is based on a redundant Fly-by-Wire (FBW) system with no mechanical back-up and includes two dual Flight Control Computers, associated sensors and actuators providing:

• the Primary Flight Control System (PFCS), which provides the helicopter with control and stability capabilities, and
• the Automatic Flight Control System (AFCS), which provides the appropriate modes of operation for the Hands-off flight required by the mission.

The Avionics System of the MRH-90, based on a state-of-the-art integrated avionic structure featuring 2 redundant MIL-STD 1553B data buses, consists of:

• the Core Avionics System; which provides all avionics functions and performance necessary to manage the basic aircraft capabilities. This encompasses the functions of monitoring and diagnostic of avionics and vehicle systems, the control and display management, navigation and communication.
• the Mission System; it provides tactical communication management, flight plan management, mission feasibility calculation and function and performance necessary to manage mission sensors used in the different mission configurations.

Information generated (flight, mission, and maintenance information) is displayed on five 8"x 8" colour Multi-Function Displays (MFD) installed in the cockpit: any required information can be displayed on any preferred display.

External removable store supports with NATO standard attachments and emergency release functions provide support for external fuel tanks.

The MRH-90 features a fully integrated on-board Monitoring and Diagnostic System (MDS) interfaced with the various monitored equipment and sub-systems for the highest testability and maintainability.