MD Helicopters MD 500E / 530F Light Helicopter, USA

The MD 500E and 530F light helicopters are manufactured by MD Helicopters Inc of Mesa, Arizona, a subsidiary of the Netherlands-based MD Helicopters, part of the RDM Group.

The company acquired the business rights of the former McDonnell Douglas Helicopters from Boeing in February 1999, excluding that of the AH-64 Apache helicopter which remains within Boeing's business interest. MD Helicopters' products also include the MD 520N, the 600N and the Explorer families of helicopters.

In August 2005, Patriarch Partners of New York bought a controlling interest in MD Helicopters from RDM.

Over 5,000 of the Hughes OH-6 and its derivatives, the MD 500 and MD 530 series helicopters, have been manufactured. The latest civil utility variants are the MD500E and MD530F. The military derivative of the helicopter is the Defender series that are in service with the United States Army.

Production of the MD500E started in 1982 and it is used as a general purpose utility and executive transport helicopter.

The MD530F is the lift version, designed for hot and high operations. It is fitted with a Rolls Royce 250-C30 turboshaft engine and has slightly larger diameter rotors and a higher power transmission. A cargo hook kit can be fitted to lift 2,000lb (907kg) external loads.

A variant of the MD530F is being used as a technology demonstrator for Boeing's Little Bird unmanned helicopter program. First autonomous flight of the Little Bird demonstrator was in July 2006.

DESIGN

The helicopter has a fully articulated, five-bladed rotor. The blades are secured by a stack of laminated steel straps. The helicopter's rotor diameter is 8.05m but the rotors can be folded for helicopter storage. A four-bladed Quiet Knight tail rotor can be fitted in place of the two-blade rotor for reduction of noise emissions.

The high set tailplane and end fins give the helicopter flight stability at high and low speeds and in sharp manoeuvres.

COCKPIT

All flight controls are manual. The helicopter is equipped with Honeywell dual KX175 navigation system receivers and Honeywell (formerly Allied Signal) KR 85 automatic direction finder, night flying lighting, attitude and directional gyroscopes and a rate climb indicator. An alternative avionics fit includes a Rockwell Collins VHF-251/231 navigation receiver fitted with an IND-350 navigation indicator and an ADF-650 automatic direction finder.

The communications system is based on a dual Honeywell KY195 transmitter / receiver and KT76 transponder or alternatively a Rockwell Collins VHF-251 and TDR-950 transceiver and transponder.

CABIN

The pilot's seat is on the left rather than on the normal right hand side of the cockpit. The front bench type seat at the front of the fuselage pod accommodates the pilot and two passengers. The rear of the cabin is fitted with individual seats for two or four passengers with baggage space allocated under the rear seats.

An alternative interior fitting to the cabin allows the helicopter to be used for medical evacuation. The rear of the cabin has room for two stretcher patients and a seat for one medical attendant.

The cabin can be air-conditioned and heated using an Aero Engineering Corporation air conditioner. For space saving, a Fargo pod mounted air conditioner can be installed.

The cabin is fitted with headsets and microphones. A public address system can be installed.

ENGINE

The MD500E helicopter is powered by a single Rolls Royce turboshaft engine, either a type 250-C20B 313kW (420shp) or a 250-C20R 336kW (450shp), providing 280kW take-off power. The MD530F is fitted with a Rolls Royce 250-C30 485kW (650shp) turboshaft engine.

The two bladder fuel tanks have a total usable fuel capacity of 242l. The refuelling point is on the starboard side. For longer range, auxiliary fuel tanks or higher capacity tanks are available.

LANDING GEAR

The tubular skid type landing gear is fitted with oleo-pneumatic shock absorbers. The helicopters can be fitted with snow skis or for amphibious operations inflated utility floats or emergency inflatable floats can be installed.