MD Helicopters MD 500

Hughes/MD 500 series
An MD 500E
Role Light utility helicopter
Manufacturer Hughes Helicopters
McDonnell Douglas Helicopter Systems
MD Helicopters, Inc.
Number built 4700 [1]
Developed from OH-6 Cayuse
Variants MD 500 Defender
MD Helicopters MD 600

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.

Contents

Design and development

The successful Hughes 500/MD 500 series began life in response to a US Army requirement for a light observation helicopter.[2] 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 an agile control response and is less susceptible to weather-cocking.

Hughes won the US 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 US 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 US 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.[2] 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 new five-blade main rotor; a four-blade tail rotor was optional.[2] The 500D was replaced by the 500E from 1982 with a pointed nose and various interior improvements such as greater head and leg room. 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.[2] 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 being dispensed with a conventional anti-torque tail rotor in favor of the Hughes/McDonnell Douglas developed NOTAR system.[2] Exhaust from a fan is directed through slots in the tail boom, using the Coandă effect to counteract the torque of the main rotor, and a controllable thruster at the end of the tail boom is used for yaw control.

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, 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 RR 250-C20R+ engine with 3-5% more power for better performance on warm days, and, with changes to the diffuser and fan rigging, increased range.

Variants

369
Military prototype designated YOH-6A.
369A
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.
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.
KH-500E
Japanese-version of the 500E. Licensed by Kawasaki Heavy Industries.[3]
NH-500E
Italian-built version of the 500E. Licensed by Breda Nardi before merging with Agusta.[1]
MD 530F (369F)
Hot and high version of the 500E powered by an Allison 250-C30B rated at 650 shp (485 kW), certififed in 1985.
MD 520N
NOTAR version of the 500E, certified in 1991.
Unmanned Little Bird Demonstrator
A civilian 530F modified by Boeing Rotorcraft Systems to develop UAV technologies for both civilian and military applications.[4]

Military

Military export version of the 500 have been marketed under the Defender name, and include the 500M, 500MD, 500MG, and 530MG.

Operators

Military operators

 Afghanistan
 Argentina
 Chile
 Finland
 Croatia
 El Salvador
 Haiti
 Honduras
 Iceland
 Iran
 Italy
 Japan
 Jordan
 Kenya
 Democratic People's Republic of Korea[6]
 Republic of Korea
 Mexico
 Panama
 Philippines
 Spain
 Taiwan
 United States

Civil operators

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

 Australia
 Brazil
 Costa Rica
 Hungary
 Mexico
 United States

In popular culture

Specifications

Model 500C

Data from The International Directory of Civil Aircraft[2]

General characteristics

Performance

MD 520N

Data from The International Directory of Civil Aircraft[2]

General characteristics

Performance

MD 530F

Data from The International Directory of Civil Aircraft[2]

General characteristics

Performance

See also

Related development
Aircraft of comparable role, configuration and era

Related lists

References

  1. ^ a b The MD Helicopters MD-500/530. Retrieved on January 16, 2008.
  2. ^ a b c d e f g h Frawley, Gerard: The International Directory of Civil Aircraft, 2003-2004, page 155. Aerospace Publications Pty Ltd, 2003. ISBN 1-875671-58-7
  3. ^ MD Helicopters MD 500/530 (United States), Helicopters in service – Rotary-wing – Civil/military.
  4. ^ "Boeing Manned/Unmanned Light Helicopter Makes First Flight", Boeing news release, October 9, 2006, accessed August 27, 2008
  5. ^ LAMilitary.org
  6. ^ Global Security.org
  7. ^ Aviation Division

External links