MD Helicopters MD 500

Last updated
MD 500
Md helicopters md-500e g-sscl arp.jpg
An MD 500E
RoleLight utility helicopter
National originUnited States
Manufacturer Hughes Helicopters
McDonnell Douglas Helicopter Systems
MD Helicopters
First flight27 February 1963
Introduction1967 [1]
StatusIn service
Primary user Various police agencies
Korean People's Air Force
Produced1967–present
Number built4,700 [2]
Developed from Hughes OH-6 Cayuse
Variants McDonnell Douglas MD 500 Defender
Boeing AH-6
Developed into 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

The MD 500 was initially produced by Hughes Helicopters as the Hughes 500. Since being introduced in 1967, numerous models have been produced, often featuring a more powerful engine or a five-bladed main rotor in place of the original four-blade counterpart. The MD 500 has been commonly used for utility work, particularly the MD 530F; it has also proven to be popular with law enforcement agencies. Production of the type was continued into the twenty-first century by Hughes' successor companies, McDonnell Douglas Helicopter Systems, and subsequently MD Helicopters. While the MD 500 series has been largely operated by civil customers, it has occasionally seen military use, even to the extent of performing front line combat operations. The Salvadoran Air Force deployed their examples during the Salvadoran Civil War, leading to several losses. North Korea also covertly obtained a fleet of MD500s for military purposes, some of which have been allegedly configured into gunships.

Design and development

Background

A Hughes 500C (Model 369HS) Hughes500.g-orrr.arp.jpg
A Hughes 500C (Model 369HS)
A Hughes 500D Hughes500.g-bioa.arp.jpg
A Hughes 500D

The Hughes 500/MD 500 series can be traced back to the early 1960s and the issuing of a requirement for a Light Observation Helicopter (LOH) for the United States Army. [3] Following a competitive tendering process, Hughes' Model 369 was selected as the winning bid, triumphing over rival submission from the helicopter manufacturers Bell and Hiller. On 27 February 1963, under the service designation of OH-6 Cayuse, the maiden flight of the type was performed. [4] [5]

The MD 500 series 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. [6] 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, which gives it an agile control response and also makes it less susceptible to weather-cocking.[ citation needed ] It had a distinctive atypical teardrop-shaped fuselage, a feature that sometimes led to personnel referring to it as the "flying egg". [4] [7]

Hughes had allegedly succeeded in the LOH contest with its OH-6 helicopter by submitting a very low and aggressive price per airframe (without an engine), to the point where the company allegedly lost money . [8] [9] Due to price escalations for both the OH-6 and spare components, the U.S. Army opted to reopen bids for the programme in 1967. [10] Seeking to profitably produce the type, Hughes offered the machine at a more realistic unit price of $56,550, however, this bid was undercut by the redesigned Bell OH-58 Kiowa, a militarised version of the JetRanger series. [8] [9] Despite this, some OH-6 helicopters were still ordered by the U.S. Army, though at a much reduced number.

Hughes/MD 500

Even prior to the first flight of the OH-6, Hughes had announced that it was working on a civilian version of the rotorcraft, which would be marketed as the Hughes 500. [5] It was available in basic five- and seven-seat configurations. [3] A utility version with a more powerful engine was offered as the 500U (later called the 500C).

During 1976, the improved Hughes 500D became the primary model. It was outfitted with a more powerful engine, a T-tail, and a new five-blade main rotor; furthermore, a four-blade tail rotor could be optionally installed. [3] [11] The 500D was replaced by the 500E from 1982 with a pointed nose and various interior improvements, such as greater head- and legroom. [12] The 530F was a more powerful version of the 500E optimized for hot and high work, being furnished with an enlarged main rotor and more powerful Allison 250-C30 engine, capable of producing up to 425 hp. [13]

During January 1984, Hughes Helicopters, the original manufacturer of the 500 series, was acquired by the American aircraft manufacturer McDonnell Douglas. Accordingly, starting in August 1985, the 500E and 530F were rebranded as the MD 500E and MD 530F Lifter respectively. [3] Following the merger between Boeing and McDonnell Douglas, the division was briefly owned by the new entity; Boeing opted to quickly sell the former MD civil helicopter lines to the newly-created MD Helicopters in early 1999. [14] [15] [16] [17] Military variants are marketed under the MD 500 Defender name.

MD 520N

A NOTAR MD 520N Md500n.g-smac.arp.jpg
A NOTAR 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. [3] 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. [18] 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 manoeuvring accidents.[ citation needed ]

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.[ citation needed ]

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.[ citation needed ]

Operational history

Civilian

The MD 500 series had proven to be popular with civilian operators, with which the type has seen use for a diverse range of purposes. According to Flying magazine, it has been particularly popular in circumstances where the primary passenger and pilot are both in the front seats, as can be typical in aerial observation, utility, and law enforcement work. [19] A minority have been used for executive transportation, for which suitable rear seating is typically provisioned; it is more common to see it used as a private/personal helicopter instead. [20]

While numerous operators have opted to procure MD 500s with the newer Rolls-Royce 250-C20 engine, which provides greater reliability and power output than older counterparts, some operators have reportedly chosen to remove these engines and substitute them with Vietnam-era surplus engines which are available even into the twenty-first century at a considerably lower purchase cost. [21]

El Salvador

At the start of the Salvadoran Civil War, the Salvadoran Air Force operated a total of six MD 500D helicopters purchased from civilian sources. Amid the conflict, these were supplemented by a further nine MD 500Es that were supplied by the United States in 1984. The type was typically operated in the gunship role, having been armed with both XM27 7.62 mm Minigun subsystems and unguided 70mm rocket pods; additional mission roles included aerial reconnaissance and liaison duties. By the end of the conflict, only two MD 500D and seven MD 500Es were reportedly in an operational condition. By 2012 Salvadoran Air Force received three brand new MD 500Es from MD Helicopters to be used for the United Nations mission in Mali, Africa. In 2022 the United States donated four MD 530Fs which were previously owned by the Department Of State Air Wing (DOSAW) which will also be used for United Nations missions. El Salvadoran Air Force as of 2023 currently operates six MD 500Es and four MD 530Fs.

North Korea

During the 1980s, North Korea managed to circumvent US export restrictions and covertly purchase a total of 87 civilian-type Hughes MD 500s through a legitimate West German export firm before the US government learned of the illegal action by North Korea and acted to prevent any further deliveries to the country. [22] Once they had arrived in North Korea, efforts continued to be made to conceal their existence, and are believed to have been flown only sparingly at least for a large portion of their service life. [22] There have been allegations that at least sixty of the helicopters delivered to North Korea have been 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). [22]

The modified MD 500 helicopters were finally revealed by North Korea in an obviously visible manner, even to international observers, during the country’s annual Victory Parade held in Pyongyang on 27 July 2013, which commemorated the 60th anniversary of the end of the Korean War in 1953. According to analysists, it is visible that the North Korea's fleet of MD 500s have been modified significantly so that they can function as light attack helicopters. Amongst these changes was mounting points and interfacing apparatus to allow them to fire Soviet-designed AT-3 Sagger anti-tank wire-guided missiles. [23]

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.
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 Allison 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.
NH-500E
Italian-built version of the 500E. License-produced by Breda Nardi before merging with Agusta. [2]
MD 520N
NOTAR (NO TAil Rotor) version of the 500E, certified in 1991. Powered by Rolls-Royce (formerly Allison) 250-C20R/2 rated at 450 shp.
MD 530F (369F)
Hot and high version of the 500E powered by a Rolls-Royce (formerly Allison) 250-C30HU rated at 650 shp (485 kW), certified in 1984.
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. [24]

Military

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

Operators

Kern County Sheriff's MD 500E Kcsd-md500-N197E-040621-02-16.jpg
Kern County Sheriff's MD 500E

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

Flag of Belgium (civil).svg  Belgium
Flag of Colombia.svg  Colombia
Flag of Costa Rica.svg  Costa Rica
Flag of Ecuador.svg  Ecuador
Flag of Finland.svg  Finland
Flag of Honduras.svg  Honduras
Flag of Hungary.svg  Hungary
Flag of Indonesia.svg  Indonesia
Flag of Italy.svg  Italy
Flag of Kenya.svg  Kenya

Flag of Kurdistan.svg  Kurdistan

Flag of North Korea.svg  North Korea
Flag of the United States (23px).png  United States

Specifications

MD 530F

MD500E orthographical image.svg

Data from MD500E Performance Specifications, [55] The International Directory of Civil Aircraft [3]

General characteristics

Performance

MD 500C

Hughes OH-6 orthographical image.svg

Data from [57]

General characteristics

Performance

See also

Related development

Aircraft of comparable role, configuration, and era

Related lists

Related Research Articles

<span class="mw-page-title-main">Hughes OH-6 Cayuse</span> 1963 scout helicopter

The Hughes OH-6 Cayuse is a single-engine light helicopter designed and produced by the American aerospace company Hughes Helicopters. Its formal name is derived from the Cayuse people, while its "Loach" nickname comes from the acronym for the Light Observation Helicopter (LOH) program under which it was procured.

<span class="mw-page-title-main">Bell 222/230</span> Family of utility helicopters

The Bell 222 is an American twin-engine light helicopter built by Bell Helicopter. The Bell 230 is an improved development with different engines and other minor changes.

<span class="mw-page-title-main">Bell 206</span> Utility helicopter family by Bell

The Bell 206 is a family of two-bladed, single- and twin-engined helicopters, manufactured by Bell Helicopter at its Mirabel, Quebec, plant. Originally developed as the Bell YOH-4 for the United States Army's Light Observation Helicopter program, it was not selected by the Army. Bell redesigned the airframe and successfully marketed the aircraft commercially as the five-place Bell 206A JetRanger. The new design was eventually selected by the Army as the OH-58 Kiowa.

<span class="mw-page-title-main">Hughes Helicopters</span> Former military vehicle company

Hughes Helicopters was a major manufacturer of military and civilian helicopters from the 1950s to the 1980s.

<span class="mw-page-title-main">Bell 407</span> Civil 7-seat utility helicopter

The Bell 407 is a four-blade, single-engine, civil utility helicopter. A derivative of the Bell 206L-4 LongRanger, the 407 uses the four-blade, soft-in-plane design rotor with composite hub developed for the United States Army's OH-58D Kiowa Warrior instead of the two-blade, semi-rigid, teetering rotor of the 206L-4.

<span class="mw-page-title-main">Bell 427</span> Type of aircraft

The Bell 427 is a twin-engine, multirole, light utility helicopter designed and manufactured by Bell Helicopter and Samsung Aerospace Industries. It has been replaced in production by the larger Bell 429.

<span class="mw-page-title-main">NOTAR</span> Alternative helicopter tail system with no external tail rotor.

NOTAR is a helicopter system which avoids the use of a tail rotor. It was developed by McDonnell Douglas Helicopter Systems. The system uses a fan inside the tail boom to build a high volume of low-pressure air, which exits through two slots and creates a boundary layer flow of air along the tailboom utilizing the Coandă effect. The boundary layer changes the direction of airflow around the tailboom, creating thrust opposite the motion imparted to the fuselage by the torque effect of the main rotor. Directional yaw control is gained through a vented, rotating drum at the end of the tailboom, called the direct jet thruster. Advocates of NOTAR assert that the system offers quieter and safer operation than a traditional tail rotor.

<span class="mw-page-title-main">MBB Bo 105</span> Helicopter

The Messerschmitt-Bölkow-Blohm Bo 105 is a light, twin-engine, multi-purpose helicopter developed by Bölkow of Ottobrunn, West Germany. It was the first light twin-engine helicopter in the world, and the first rotorcraft that could perform aerobatic maneuvers such as inverted loops. The Bo 105 features a hingeless rotor system, a pioneering innovation in helicopters when it was introduced into service in 1970. Production of the Bo 105 began at the then-recently merged Messerschmitt-Bölkow-Blohm.

<span class="mw-page-title-main">MD Helicopters MH-6 Little Bird</span> Attack helicopter used in United States special operations

The Boeing MH-6M Little Bird and its attack variant, the AH-6, are light helicopters used for special operations in the United States Army. Originally based on a modified OH-6A, it was later based on the MD 500E, with a single five-bladed main rotor. The newest version, the MH-6M, is based on the MD 530F and has a single, six-bladed main rotor and four-bladed tail rotor.

<span class="mw-page-title-main">Hiller OH-23 Raven</span> Family of light helicopters

The Hiller OH-23 Raven is a three-place, military light observation helicopter based on the Hiller Model 360. The Model 360 was designated by the company as the UH-12, which was first flown in 1948. A Hiller UH-12 was the first helicopter to make a transcontinental flight across the USA, in 1949.

<span class="mw-page-title-main">Allison Model 250</span> Turboshaft aircraft engine

The Allison Model 250, now known as the Rolls-Royce M250, is a highly successful turboshaft engine family, originally developed by the Allison Engine Company in the early 1960s. The Model 250 has been produced by Rolls-Royce since it acquired Allison in 1995.

<span class="mw-page-title-main">MD Helicopters</span> American aerospace manufacturer

MD Helicopters, LLC. is an American aerospace manufacturer. It produces light utility helicopters for commercial and military use. The company was a subsidiary of Hughes Aircraft until 1984, when McDonnell Douglas acquired it and renamed it McDonnell Douglas Helicopter Systems. It later became MD Helicopters in 1999 after McDonnell Douglas merged with Boeing.

<span class="mw-page-title-main">MD Helicopters MD Explorer</span> Light twin-engine utility helicopter

The MD Helicopters MD Explorer is a light twin-engined utility helicopter designed and initially produced by the American rotorcraft specialist McDonnell Douglas Helicopter Systems.

<span class="mw-page-title-main">MD Helicopters MD 600</span> Light utility helicopter

The MD Helicopters MD 600N is a light utility civilian helicopter designed in the United States. It is a stretched eight-seat development of the five-seat MD 520N helicopter.

<span class="mw-page-title-main">Fairchild Hiller FH-1100</span> Type of aircraft

The Fairchild Hiller FH-1100 is a single-engine, single two-bladed rotor, light helicopter designed and produced by the American aircraft manufacturer Fairchild Hiller.

<span class="mw-page-title-main">Bell YOH-4</span> Type of aircraft

The Bell YOH-4 was a single-engine, single-rotor light helicopter, developed for the United States Army's Light Observation Helicopter program. While the YOH-4A was unsuccessful in the original LOH competition, Bell redesigned it as the sleek Bell 206A JetRanger for the commercial market, and enjoyed instant and lasting success. In 1967, the Army reopened the LOH competition, and the 206A-based OH-58 Kiowa was selected.

<span class="mw-page-title-main">McDonnell Douglas MD 500 Defender</span> Light utility and scout helicopter

The McDonnell Douglas Helicopter Systems MD 500 Defender is a light multi-role military helicopter based on the MD 500 light utility helicopter and OH-6 Cayuse Light Observation Helicopter.

<span class="mw-page-title-main">Bell UH-1 Iroquois variants</span> Variants of the American military utility helicopter

The Bell UH-1 Iroquois military helicopter, first introduced in 1959, is the first production member of the prolific Huey family of helicopters, and was itself developed in over twenty variants, which are listed below.

<span class="mw-page-title-main">Boeing AH-6</span> Type of aircraft

The Boeing AH-6 is a series of light helicopter gunships based on the MH-6 Little Bird and MD 500 family. Developed by Boeing Rotorcraft Systems, these include the Unmanned Little Bird (ULB) demonstrator, the A/MH-6X Mission Enhanced Little Bird (MELB), and the proposed AH-6I and AH-6S.

References

Citations

  1. ↑ "Hughes 369 / 500 / OH-6". all-aero.com. Retrieved 4 June 2018.
  2. 1 2 "The MD Helicopters MD-500/530". airliners.net. Retrieved 16 January 2008.
  3. 1 2 3 4 5 6 Frawley, Gerard (2003). The International Directory of Civil Aircraft, 2003-2004. Aerospace Publications Pty Ltd. p. 155. ISBN   1-875671-58-7.
  4. 1 2 McGowen 2005, p. 105.
  5. 1 2 McClellan 1989, p. 46.
  6. ↑ "MD 500E". MD Helicopters. Retrieved 2 November 2022.
  7. ↑ McClellan 1989, p. 44.
  8. 1 2 Cefaratt 2002, p. 77.
  9. 1 2 Real, Jack. "The Real Story." Vertiflite, Fall/Winter 1999, pp. 36–39.
  10. ↑ McGowen 2005, p. 112.
  11. ↑ McClellan 1989, pp. 46, 50.
  12. ↑ McClellan 1989, pp. 46-47.
  13. ↑ McClellan 1989, p. 47.
  14. ↑ "Bell buys Boeing's MD Singles". Flying. Vol. 125, no. 5. May 1998. p. 32. ISSN   0015-4806.
  15. ↑ Frawley 2003, p. 155.
  16. ↑ "Boeing Completes Sale Of Light Helicopter Product Lines To RDM". Boeing. 19 February 1999. Archived from the original on 28 December 2007.
  17. ↑ "Boeing Announces Sale of its Light Helicopter Product Lines". Boeing. Archived from the original on 13 February 2008. Retrieved 7 February 2008.
  18. ↑ McClellan 1989, p. 52.
  19. ↑ McClellan 1989, pp. 47-48.
  20. ↑ McClellan 1989, p. 48.
  21. ↑ Huber, Mark (1 November 2022). "Hansen Helicopters' 'Highway to Hell'". AIN Online.
  22. 1 2 3 Cenciotti, David (31 July 2013). "North Korea's Illegal Helicopters Emerge". Businessinsider.com. Retrieved 3 December 2021.
  23. ↑ "North Korea's (illegally supplied) armed Hughes 500E helicopters emerge after 30 years in the dark". The Aviationist. 30 July 2013.
  24. ↑ "Boeing Manned/Unmanned Light Helicopter Makes First Flight" (Press release). Boeing. 9 October 2006. Archived from the original on 14 October 2012. Retrieved 29 April 2013.
  25. ↑ "McDonnell Douglas MD520N". www.belgian-wings.be. Archived from the original on 2 February 2011.
  26. ↑ Rivas 2015, p. 121.
  27. ↑ "Overlook of the SVA". au.af.mil. Retrieved 19 May 2017.
  28. ↑ "El Tiempo: La Policía del Azuay recibe hoy helicóptero". eltiempo.com.ec (in Spanish). Archived from the original on 18 October 2016.
  29. ↑ "Finnish Defence Forces". maavoimat.fi (in Finnish).
  30. ↑ Erich (5 October 2014). "Hughes 500 (369D) – Aeroflight". Aeroflight.co.uk. Retrieved 3 December 2021.
  31. ↑ "Amerikai helikopterek Magyarországon ("American helicopters in Hungary")". iho.hu (in Hungarian).
  32. ↑ "Hughes 500C TNI AU: Sempat Jadi Helikopter Latih Lanjut, Cikal Bakal Heli Serbu Ringan MD530G". indomiliter.com. 31 May 2016. Retrieved 11 December 2020.
  33. ↑ "Skadron Udara 7". tni-au.mil.id. 16 January 2010. Archived from the original on 11 December 2020. Retrieved 11 December 2020.
  34. ↑ Roelofs, Erik (April 2012). "Italy's Flying Foresters". Air International . Vol. 82, no. 4. pp. 78–81. ISSN   0306-5634.
  35. ↑ Kenyatte, Patrick. "Kenya Defence Forces induct MD 530F helicopters". Military Africa. Retrieved 22 January 2024.
  36. ↑ "Kurdistan government orders 12 MD 530F helicopters". Helicopter Investor. Retrieved 2023-11-07.
  37. ↑ "World Air Forces 2013" (PDF). Flightglobal Insight. 2013. Retrieved 28 February 2013.
  38. ↑ "ACADEMI -- ex-Blackwater -- Boosts State Dept Business, Eyes Acquisitions". defense.aol.com. Archived from the original on 12 April 2013. Retrieved 28 February 2013.
  39. ↑ "Columbus Police Helicopter Unit". columbuspolice.org. Archived from the original on 1 June 2016. Retrieved 31 May 2016.
  40. ↑ "Fresno County Sheriff's Office receives new helicopter". kmph.com. Retrieved 26 February 2018.
  41. ↑ "Glendale Police Newsletter" (PDF). ci.glendale.ca.us. Retrieved 16 October 2013.
  42. ↑ "Hawaii County Fire Dept replaces 500D with new 500E". helihub.com. 29 July 2010. Retrieved 28 February 2013.
  43. ↑ "Houston Police Dept celebrates 40 years of air support". helihub.com. 18 November 2010. Retrieved 28 February 2013.
  44. ↑ "Kansas City Police orders three new MD500Es". HeliHub.com. 20 February 2012. Retrieved 3 December 2021.
  45. ↑ "MD Helicopters Delivers New MD 530F to Las Vegas Metro Police Department". helis.com. Retrieved 28 February 2013.
  46. ↑ "Police Department Aviation Unit | Nashville.gov". www.nashville.gov. Retrieved 2023-12-12.
  47. ↑ "Pasadena Police hold public launch of new 500E". helihub.com. 22 March 2010. Retrieved 28 February 2013.
  48. ↑ "Prince George's County Police Department to Expand Aviation Section with new MD 520N - MD Helicopters". www.mdhelicopters.com. Retrieved 5 November 2019.
  49. ↑ "Aviation Division". Archived from the original on 21 July 2011. Retrieved 28 February 2011.
  50. ↑ "ASTREA - Aerial Support to Regional Enforcement Agencies". sdsheriff.net. Retrieved 28 February 2013.
  51. ↑ "Official Website of the Metropolitan Police Department, City of St. Louis". www.slmpd.org. Retrieved 6 July 2017.
  52. ↑ "Police Department | Law & Public Safety". www.stlouisco.com. St. Louis County. Retrieved 7 July 2017.
  53. ↑ "Oakland Police Helicopter ARGUS is assisting patrol officers on our city streets. This is one of many enforcement actions OPD is taking to deter and enforce illegal Sideshow activity". Twitter . Retrieved 15 May 2021.
  54. ↑ "I Bought An Abandoned Helicopter From South America..." YouTube.
  55. ↑ "MD500E Performance Specifications" (PDF). Archived from the original (PDF) on 22 January 2012.
  56. 1 2 Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.
  57. ↑ Taylor, John W.R., ed. (1971). Jane's All the World's Aircraft 1971-72 (62nd ed.). London: Sampson Low, Marston & Company. pp. 322–323. ISBN   9780354000949.

Bibliography

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.