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MD Helicopters MD 500

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MD Helicopters MD 500

The MD Helicopters MD 500 series is an American family of light utility civilian and military helicopters. The MD 500 was developed from the Hughes 500, a civilian version of the US Army's OH-6A Cayuse/Loach. The series currently includes the MD 500E, MD 520N, and MD 530F.


Design and development

The successful Hughes 500/MD 500 series began life in response to a U.S. Army requirement for a light observation helicopter. Hughes' Model 369 won the contest against competition from Bell and Hiller. The OH-6 Cayuse first flew in February 1963.

The 500 series design features shock-absorbing landing skid struts, a turboshaft engine mounted at a 45-degree angle toward the rear of the cabin pod, a fuel tank cell under the floor and the battery in the nose. The engine exhaust port is located at the end of the cabin pod underneath the tailboom. It has a short-diameter main rotor system and a short tail, giving it agile control response and is less susceptible to weather-cocking.

Hughes won the U.S. Army's LOH contest with its OH-6 helicopter by submitting a very low and aggressive price per airframe (without an engine). Due to rising prices, the U.S. Army later re-opened the contest, where Hughes offered the machine at a more realistic price, but was undercut by the redesigned Bell OH-58 Kiowa (military JetRanger). OH-6 helicopters were still ordered by the U.S. Army, though at a much reduced number.

Hughes/MD 500

Prior to the OH-6's first flight, Hughes announced it was developing a civil version, to be marketed as the Hughes 500, available in basic five- and seven-seat configurations. A utility version with a more powerful engine was offered as the 500U (later called the 500C).

The improved Hughes 500D became the primary model in 1976, with a more powerful engine, a T-tail, and a new five-blade main rotor; a four-blade tail rotor was optional. The 500D was replaced by the 500E from 1982 with a pointed nose and various interior improvements, such as greater head- and legroom. The 530F was a more powerful version of the 500E optimized for hot and high work.

McDonnell Douglas acquired Hughes Helicopters in January 1984, and from August 1985 the 500E and 530F were built as the MD 500E and MD 530F Lifter. In 2014 an MD530F performed airshow acrobatics, piloted by eighty-two-year-old Dennis Kenyon. Following the 1997 Boeing-McDonnell Douglas merger, Boeing sold the former MD civil helicopter lines to MD Helicopters in early 1999. Military variants are marketed under the MD 500 Defender name.

MD 520N

The MD 520N introduced a revolutionary advance in helicopter design, dispensing with a conventional anti-torque tail rotor in favor of the Hughes/McDonnell-Douglas-developed NOTAR system. Exhaust from a fan is directed through slots in the tailboom, using the Coandă effect to counteract the torque of the main rotor, and a controllable thruster at the end of the tailboom is used for yaw control. Because the fan is enclosed in the tailboom, tail rotor noise—the major source of noise from most conventional helicopters—was significantly reduced. It also eliminated the vulnerable exposed tail rotor blades, eliminating the possibility of persons being injured or killed on the ground and the cause for many confined area maneuvering accidents.

McDonnell Douglas originally intended to develop the standard MD 520N alongside the more powerful hot-and-high optimized MD 530N; both were launched in January 1989 and were based on the conventional MD 500E. The MD 530N was the first to fly, on December 29, 1989, and the MD 520N first flew on May 1, 1990. Development of the MD 530N was suspended when McDonnell Douglas decided that the MD 520N met most customer requirements for the 530N. Certification for the MD 520N was awarded on September 13, 1991, and the first was delivered on December 31 that year.

In 2000, MD Helicopters announced enhancements to the MD 520N, including an improved Rolls-Royce 250-C20R+ engine with 3% to 5% more power for better performance on warm days, and changes to the diffuser and fan rigging, also increased range.

El Salvador

During the Salvadoran Civil War, the Salvadoran Air Force operated six MD 500Ds, which were supplemented later by nine MD 500Es supplied by the United States in 1983. These were used as gunships, armed with 7.62 mm Miniguns and unguided rockets, as well as being used for reconnaissance and liaison duties. One MD 500D and two MD 500Es were lost to SA-7 missiles in 1989 and 1990. By the end of the conflict, only one MD 500D and six MD 500Es were in operational condition.

North Korea

In 1985, North Korea managed to circumvent US export-control barriers to purchase 87 civilian-type Hughes MD 500s from a West German export firm (the purchase was conducted covertly) before the US government learnt of the illegal action by North Korea and moved to stop further deliveries to the country. There are reports indicating that at least sixty of the helicopters delivered to North Korea were modified to serve as helicopter-gunships. As South Korea produces the MD 500 domestically (under license) for use by its own armed forces, the modified helicopters operated by North Korea were deemed useful in conducting covert or deceptive operations against South Korea (such as incursions past the border).

The modified MD 500 helicopters were finally revealed by North Korea and seen by the USA and European countries during North Korea's Victory Parade held on the 27th of July in 2013 in Pyongyang, to commemorate the 60th anniversary of the end of the Korean War in 1953. Images and analyses done regarding North Korea's MD 500 helicopters show that they have been modified significantly to serve as light attack helicopters, such as modification work on the helicopters for them to be mounted with Soviet-designed AT-3 Sagger anti-tank wire-guided missiles.


Military prototype designated YOH-6A.
Military production designated OH-6.
MD 500C (369H)
Improved five-seat commercial variant powered by an Allison 250-C18B rated at 317 shp (236 kW); certified in 1966.
Kawasaki-Hughes 369HS
Built under license by Kawasaki Heavy Industries in Japan alongside OH-6J.
MD 500M Defender (369HM)
Military export version as the MD 500 Defender; certified in 1968.
MD 500C (369HS)
Improved four-seat commercial variant by an Allison 250-C20 rated at 400 shp (298 kW); certified in 1969.
MD 500C (369HE)
A 369HS with higher standard interior fittings, Certified in 1969.
MD 500D (369D)
New commercial version from 1976 powered by an Alison 250-C20B rated at 420 shp (313 kW); certified in 1976.
MD 500E (369E)
Executive version of the 500D with recontoured nose; certified in 1982.
Italian-built version of the 500E. License-produced by Breda Nardi before merging with Agusta.
MD 530F (369F)
Hot and high version of the 500E powered by an Allison 250-C30B rated at 650 shp (485 kW), certified in 1985.
MD 520N
NOTAR version of the 500E, certified in 1991.
Unmanned Little Bird Demonstrator and AH-6
A civilian 530F modified by Boeing Rotorcraft Systems to develop UAV technologies for both civilian and military applications.


For military variants, see McDonnell Douglas MD 500 Defender and Hughes OH-6 Cayuse


The MD 500 is widely operated by private individuals, companies and law enforcement agencies around the world.

  • Calgary Police Service
  •  Colombia
  • National Police of Colombia
  •  Ecuador
  • National Police of Ecuador
  •  Finland
  • Utti Jaeger Regiment
  •  Hungary
  • Hungarian Police
  •  Democratic People's Republic of Korea
  • Korean People's Air Force
  •  Italy
  • State Forestry Corps
  •  United States
  • Academi
  • Columbus Police
  • Glendale Police Department
  • Hawaii County Fire Dept
  • Houston Police Department
  • Kansas City Police Department
  • Las Vegas Police Department
  • Mesa Police Department
  • Pasadena Police Department
  • Riverside Police Department
  • San Diego County Sheriff's Department
  • Model 500C

    Data from The International Directory of Civil Aircraft

    General characteristics

  • Crew: one–two
  • Capacity: five total
  • Length: 30 ft 10 in (9.4 m)
  • Rotor diameter: 26 ft 4 in (8.03 m)
  • Height: 8 ft 2 in (2.48 m)
  • Empty weight: 1,088 lb (493 kg)
  • Max. takeoff weight: 2,250 lb (1,157 kg)
  • Powerplant: 1 × Allison 250-C20 Turboshaft, 278 hp (207 kW)
  • Performance

  • Maximum speed: 152 knots (175 mph, 282 km/h)
  • Cruise speed: 125 kn (144 mph, 232 km/h)
  • Range: 375 mi (605 km)
  • Service ceiling: 16,000 ft (4,875 m)
  • Rate of climb: 1,700 ft/min (8.6 m/s)
  • Model 500E

    Data from "MD Helicopters web site" (PDF). 

    General characteristics

  • Crew: one–two
  • Capacity: five total
  • Length: 30.81 ft (9.4 m)
  • Rotor diameter: 26.4 ft (8.1 m)
  • Height: 8.4 ft (2.6 m)
  • Disc area: 586.8 ft² (54.5 m²)
  • Empty weight: 1,481 lb (672 kg)
  • Max. takeoff weight: 3,000 lb (1,361 kg)
  • Powerplant: 1 × Allison 250-C20B Turboshaft, 420 hp (313 kW)
  • Performance

  • Maximum speed: 152 knots (175 mph, 282 km/h)
  • Cruise speed: 135 kn (155 mph, 250 km/h)
  • Range: 267 mi (429 km)
  • Service ceiling: 16,000 ft (4,877 m)
  • Rate of climb: 1,770 ft/min (9 m/s)
  • MD 530F

    Data from The International Directory of Civil Aircraft

    General characteristics

  • Crew: one–two
  • Capacity: five total
  • Length: 32 ft 7 in (9.94 m)
  • Rotor diameter: 27 ft 4 in (8.33 m)
  • Height: 8 ft 9 in (2.48 m)
  • Disc area: 587.5 sq ft (54.6 sq m)
  • Empty weight: 1,591 lb (722 kg)
  • Max. takeoff weight: 3,550 lb (1,610 kg)
  • Powerplant: 1 × Allison 250-C30 Turboshaft, 650 hp (485 kW)
  • Performance

  • Maximum speed: 152 knots (175 mph, 282 km/h)
  • Cruise speed: 135 kn (155 mph, 250 km/h)
  • Range: 232 nmi (267 mi, 430 km)
  • Service ceiling: 18,700 ft (5,700 m)
  • Rate of climb: 2,070 ft/min (10.5 m/s)
  • References

    MD Helicopters MD 500 Wikipedia

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