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The aft cabin belly is also a double- wall design, providing space for a newly-designed, two-cell, crash- resistant fuel system.
The MD 600N® floor is rated at 1350 pounds (not to exceed 115 pounds per square foot) and offers cargo tie down points for virtually any shape of cargo.
The NOTAR® tailboom is carbon composite structure with a horizontal stabilizer constructed of carbon composite and Kevlar. The vertical stabilizers are made of fiberglass.
The forward canopy transparencies are secured with screws, easing removal for maintenance and access to the aft side of the instrument panel.
SYSTEM DESCRIPTION
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3.3. Engine.
The engine used in the MD 600N® is the Rolls-Royce 250-C47M gas turbine engine. The 250-C47M produces 808 shaft horsepower, derated in the MD 600N® to 600 shaft horsepower for takeoff and 530 horsepower at maximum continuous operation. Derating the engine extends its service life and reduces maintenance while offering increased performance at higher-density altitudes.
The 250-C47M engine is equipped with a full authority digital engine control (FADEC) unit. This system greatly enhances engine control and provides several features and benefits that reduce pilot workload, improve flight safety and decrease maintenance requirements. A separate hydro-pneumatic fuel control system is provided for manual backup.
The engine control unit records all important engine parameters and provides maintenance information to the customer through a system of maintenance lights. Also available is an optional maintenance package that includes software and hardware to allow downloading of the recorded parameters from the ECU onto a standard personal computer.
Pilot workload is simplified with automatic starting and turbine temperature limiting. Provisions for main rotor and NOTAR® fan load anticipation provides stable rotor speed throughout the flight envelope.
Maintainability is enhanced by removing the requirement for PTG rigging, and by eliminating pneumatic control lines, accumulators and connections. No field authorized adjustments are required. Control system features allow temperature limiting, further reducing the potential for engine damage. The standard analog/digital TOT gauge records one-time exceedances.
The engine compartment is located aft of the mid-compartment, separated by a firewall. Access to the engine compartment is through two doors contoured to the aerodynamic lines of the fuselage. The engine arrangement provides access for inspection and maintenance without the need for ladders or work platforms. An engine compartment fire detection system is standard on the MD 600N®.
3.4. Drive System.
The main transmission in the MD 600N® is a new design based on the proven concepts of the MD 500® Series transmissions. The transmission power limit is 600 shaft horsepower for takeoff and 530 shaft horsepower continuous. It has been designed to achieve a life of 3,000 hours before overhaul, and can be removed from the aircraft without removing any of the main rotor components.
An overrunning clutch transmits power from the engine to the engine drive shaft. The clutch has no external controls and disengages automatically during autorotation and engine shutdown. The engine oil cooler blower is belt-driven off the main drive shaft and draws its cooling air from the air inlet fairing to supply ambient air to the engine and transmission oil coolers and to the engine compartment.
This transmission is common with the MD 600N® and all other new MD 500® Series helicopters.
SYSTEM DESCRIPTION
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3.5. Main Rotor System.
Unique to MD Helicopters products is the static mast-hub support system. This hub support system uses a static mast, rigidly attached to the fuselage. All dynamic loads are transmitted through this mast, rather than through the transmission. A separate, inner drive shaft transmits engine torque to the main rotor hub.
This feature offers improved flight control integrity and helps retain rotor system components in the event of a main rotor blade strike. Additionally, this approach allows for the design of a main transmission that is lighter in weight, and can be removed without disturbing the hub or control systems.
The MD 600N® features a six-blade, fully articulated main rotor assembly. The blade retention system is a unique “strap pack” design which provides restraint and allows all three degrees of freedom for rotor blade travel. The system has redundant load paths for an added measure of safety.
Elastomeric lead/lag dampers are standard in the MD 600N® main rotor system. The blades are of all metal construction and utilize nickel abrasion strips to minimize the effects of erosion from airborne particulate matter. The blades are secured to the hub with quick-release lever-type pins that facilitate rapid blade removal.
The main rotor system of the MD 600N® provides handling qualities with direct control responses. In addition, the six-blade design reduces vibrations, providing an exceptionally smooth ride. Transient positive load factors of 3.5 g’s and negative load factors of 0.0 g’s are attainable in the MD 600N®.
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MD600 TechDescription Feb09(5)
