MD Helicopters MD 520N

Type (Muster)
Light multi-purpose turbine helicopter (leichter Mehrzweckhubschrauber)

Country (Land)
USA

Manufacturer (Hersteller)
MD Helicopters Inc.
5000 East McDowell Road
Mesa, Arizona 85215-9797
USA

Phone: 001-480/891-8014
Fax: 001-480/891-8018

General data (Allgemeine Angaben)
Crew (Besatzung): 1
Passengers (Passagiere): 4

Power plant (Antrieb): Rolls-Royce (Allison) C250-C20R-2
Power (Leistung): 317 kW (425 shp) fot take-off and 280 kW (375 shp) maximum continuous. Transmission rated at 317 kW

Take-off noise level:85,4 EPNdB
Approach noise level: 87,9 EPNdB
Flyover noise level: 80,2 EPNdB

Dimensions (Abmessungen)
Overall length, rotors turning (Länge über drehende Rotoren): 9,78 m
Fuselage length (Rumpflänge): 7,77 m
Height (Höhe): 2,74 m or 3,01 m with extended skids
Width over landing gear (Breite): 1,92 m
Span over tail (Leitwerksspannweite): 2.01 m
Rotor diameter (Rotordurchmesser): 8,33 m
Main rotor disk area (Rotorkreisfläche): 54,51 sq m

Weights (Massen)
Empty weight, standard (Leermasse): 719 kg
Usefull load (Zuladung): 800 kg
External load (Außenlast): 1004 kg
Fuel (Kraftstoff): 183 kg
Max. take-off weight (Max. Startmasse): 1520 kg normal, 1745 kg with external load

Performance (Flugleistungen)
Max. speed (höchstzulässige Geschwindigkeit): 280 km/h
Maximum cruise speed (Max. Reisegeschwindigkeit): 249 km/h (135 kts)
Max. climb rate (Steigrae): 9,4 m/s at ISA, sea level
Service ceiling (Dienstgipfelhöhe): 4320 m
Hover ceiling (Schwebeflughöhe)
- out of ground effect (ohne Bodeneffekt, ISA): 1707 m at ISA conditions, 1292 m at ISA + 20 deg C
- in ground effect (im Bodeneffekt): 2835 m
Maximum Range (Reichweite): 489 km
Endurance (Flugdauer): 2 h 24 min

Costs (Kosten)
MD Helicopters sold the MD 520N for 900 000 US-Dollars in 1999 and kept this in early 2000.
Direct operating costs were put at 192 US-Dollars/hour in 1999.

Customers (Kunden)
By December 1999, MD Helicopters said that 89 MD 520Ns are in service. Among the customers are:

Phoenix Police Department (first delivery 31. Oct. 1991)
Burbank police
Huntington Beach police
Los Angeles plice
San Jose police
Hernando County police
Salvador Policia National Civil

According to AIA statistics, MD 520 series deliveries were 5 in 1999, 2 in 1998, 2 in 1997, 5 in 1996, 10 in 1995, 9 in 1994, 21 in 1993, 17 in 1992, and 3 in 1991.

Remarks (Bemerkungen)
The MD 520N is the newest member of the MD 500 Series, which began with the famout OH-6A Cayuse in the 60s. Its man difference concerns the tail, which has no rotor to cancel torque, but the so-called NOTAR system, which works with sideways "lift" produced by the tailboom. Air is released through long slots along the right side of the boom and through a directional thurster at the end of the boom. It captures the downwash of the main rotor.

History (Geschichte)
Experiments with an OH-6A NOTAR testbed began on 17. December 1981, with mixed results at first. After an extensive modification, flying was resumed on 12 March 1986 and completed in June that year.
McDonnell Douglas then announced the introduction of the NOTAR technology in two civil variants in February 1988 at the HAI Convention. Official launch of the MD 520N and the higher-powered MD 530N followed in January 1989.
The MD 530N first flew on 29 December 1989, but this model was not certified and no production followed.
The MD 520N completed its maiden flight on 1 May 1990. The first production helicopter took to the air on 28 June 1991. Certification was achieved on 13. September that year, and deliveries (to the Phoenix Police Department) began on 31 October 1991.
After a year-long search for potential buyers and US Government rejection of a sale to Bell, Boeing finally completed the disposal of its civil helicopter business (inherited from the McDonnell Douglas merger) in February 1999. Newly formed MD Helicopters took over ownership of the single and twin-engine commercial products, including the MD 520N. The company is an indirect subsidiary of RDM Holding, a European-based industrial group.
Boeing will provide technical support for up to five years and continued to manufacture some parts for a transition period. Assembly will stay at the Boeing facility at Falcon Field. This was first leased by MD Helicopters but will be bought in 2000.

Last updated 12. March 2000

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