Light utility helicopter family
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
.
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
[
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]
Background
[
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]
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
[
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]
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
[
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]
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
Coand? 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
[
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]
Civilian
[
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]
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
[
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]
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
[
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]
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
[
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]
- 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
[
edit
]
- For military variants, see
McDonnell Douglas MD 500 Defender
and
Hughes OH-6 Cayuse
.
Operators
[
edit
]
The MD 500 is widely operated by private individuals, companies and law enforcement agencies around the world.
-
Belgium
-
Colombia
-
Costa Rica
-
Ecuador
-
Finland
-
Honduras
-
Hungary
-
Indonesia
-
Italy
-
Kenya
Kurdistan
-
North Korea
-
United States
Specifications
[
edit
]
MD 530F
[
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]
Data from
MD500E Performance Specifications,
[55]
The International Directory of Civil Aircraft
[3]
General characteristics
- Crew:
2
- Capacity:
3 passengers
- Length:
32 ft 7 in (9.93 m)
- Height:
8 ft 9 in (2.67 m)
- Empty weight:
1,591 lb (722 kg)
- Max takeoff weight:
3,550 lb (1,610 kg)
- Powerplant:
1 ×
Allison 250-C30
turboshaft
engine, 650 shp (480 kW)
- Main rotor diameter:
27 ft 4 in (8.33 m)
- Main rotor area:
587.5 sq ft (54.58 m
2
) *
Blade section:
-
NACA 0012
[56]
Performance
- Maximum speed:
152 kn (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)
MD 500C
[
edit
]
Data from
[57]
General characteristics
- Crew:
2
- Capacity:
2
- Length:
30 ft 3.75 in (9.2393 m)
- Height:
8 ft 1.5 in (2.477 m)
- Empty weight:
1,229 lb (557 kg)
- Max takeoff weight:
2,700 lb (1,225 kg)
- Fuel capacity:
61.5 US gal (51 imp gal; 233 L) in two 50% self-sealing bladder tanks under rear cabin floor
- Powerplant:
1 ×
Allison T63-A-5A
turboshaft
engine, 317 shp (236 kW)
- Main rotor diameter:
26 ft 4 in (8.03 m)
- Main rotor area:
544.63 sq ft (50.598 m
2
) *
Blade section:
-
NACA 0012
[56]
Performance
- Maximum speed:
130 kn (150 mph, 240 km/h)
- Cruise speed:
130 kn (150 mph, 240 km/h)
- Range:
330 nmi (380 mi, 610 km) at 5,000 ft (1,524 m)
- Ferry range:
1,354 nmi (1,558 mi, 2,508 km) with 1,300 lb (590 kg) of fuel
- Service ceiling:
15,800 ft (4,800 m) *
Hover ceiling OGE:
7,300 ft (2,225 m)
- Hover ceiling IGE:
11,800 ft (3,597 m)
- Rate of climb:
2,070 ft/min (10.5 m/s)
See also
[
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]
Related development
Aircraft of comparable role, configuration, and era
Related lists
References
[
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]
Citations
[
edit
]
- ^
"Hughes 369 / 500 / OH-6"
.
all-aero.com
. Retrieved
4 June
2018
.
- ^
a
b
"The MD Helicopters MD-500/530"
. airliners.net
. Retrieved
16 January
2008
.
- ^
a
b
c
d
e
f
Frawley, Gerard (2003).
The International Directory of Civil Aircraft, 2003-2004
. Aerospace Publications Pty Ltd. p. 155.
ISBN
1-875671-58-7
.
- ^
a
b
McGowen 2005, p. 105.
- ^
a
b
McClellan 1989, p. 46.
- ^
"MD 500E"
. MD Helicopters
. Retrieved
2 November
2022
.
- ^
McClellan 1989, p. 44.
- ^
a
b
Cefaratt 2002, p. 77.
- ^
a
b
Real, Jack. "The Real Story."
Vertiflite
, Fall/Winter 1999, pp. 36?39.
- ^
McGowen 2005, p. 112.
- ^
McClellan 1989, pp. 46, 50.
- ^
McClellan 1989, pp. 46-47.
- ^
McClellan 1989, p. 47.
- ^
"Bell buys Boeing's MD Singles"
.
Flying
. Vol. 125, no. 5. May 1998. p. 32.
ISSN
0015-4806
.
- ^
Frawley 2003, p. 155.
- ^
"Boeing Completes Sale Of Light Helicopter Product Lines To RDM"
. Boeing. 19 February 1999. Archived from
the original
on 28 December 2007.
- ^
"Boeing Announces Sale of its Light Helicopter Product Lines"
. Boeing. Archived from
the original
on 13 February 2008
. Retrieved
7 February
2008
.
- ^
McClellan 1989, p. 52.
- ^
McClellan 1989, pp. 47-48.
- ^
McClellan 1989, p. 48.
- ^
Huber, Mark (1 November 2022).
"Hansen Helicopters' 'Highway to Hell'
"
.
AIN Online
.
- ^
a
b
c
Cenciotti, David (31 July 2013).
"North Korea's Illegal Helicopters Emerge"
. Businessinsider.com
. Retrieved
3 December
2021
.
- ^
"North Korea's (illegally supplied) armed Hughes 500E helicopters emerge after 30 years in the dark"
. The Aviationist. 30 July 2013.
- ^
"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
.
- ^
"McDonnell Douglas MD520N"
.
www.belgian-wings.be
. Archived from
the original
on 2 February 2011.
- ^
Rivas 2015, p. 121.
- ^
"Overlook of the SVA"
. au.af.mil
. Retrieved
19 May
2017
.
- ^
"El Tiempo: La Policia del Azuay recibe hoy helicoptero"
.
eltiempo.com.ec
(in Spanish). Archived from
the original
on 18 October 2016.
- ^
"Finnish Defence Forces"
.
maavoimat.fi
(in Finnish).
- ^
Erich (5 October 2014).
"Hughes 500 (369D) ? Aeroflight"
. Aeroflight.co.uk
. Retrieved
3 December
2021
.
- ^
"Amerikai helikopterek Magyarorszagon ("American helicopters in Hungary")"
.
iho.hu
(in Hungarian).
- ^
"Hughes 500C TNI AU: Sempat Jadi Helikopter Latih Lanjut, Cikal Bakal Heli Serbu Ringan MD530G"
.
indomiliter.com
. 31 May 2016
. Retrieved
11 December
2020
.
- ^
"Skadron Udara 7"
.
tni-au.mil.id
. 16 January 2010.
Archived
from the original on 11 December 2020
. Retrieved
11 December
2020
.
- ^
Roelofs, Erik (April 2012). "Italy's Flying Foresters".
Air International
. Vol. 82, no. 4. pp. 78?81.
ISSN
0306-5634
.
- ^
Kenyatte, Patrick.
"Kenya Defence Forces induct MD 530F helicopters"
.
Military Africa
. Retrieved
22 January
2024
.
- ^
"Kurdistan government orders 12 MD 530F helicopters"
.
Helicopter Investor
. Retrieved
2023-11-07
.
- ^
"World Air Forces 2013"
(PDF)
. Flightglobal Insight. 2013
. Retrieved
28 February
2013
.
- ^
"ACADEMI -- ex-Blackwater -- Boosts State Dept Business, Eyes Acquisitions"
. defense.aol.com. Archived from
the original
on 12 April 2013
. Retrieved
28 February
2013
.
- ^
"Columbus Police Helicopter Unit"
. columbuspolice.org. Archived from
the original
on 1 June 2016
. Retrieved
31 May
2016
.
- ^
"Fresno County Sheriff's Office receives new helicopter"
.
kmph.com
. Retrieved
26 February
2018
.
- ^
"Glendale Police Newsletter"
(PDF)
. ci.glendale.ca.us
. Retrieved
16 October
2013
.
- ^
"Hawaii County Fire Dept replaces 500D with new 500E"
. helihub.com. 29 July 2010
. Retrieved
28 February
2013
.
- ^
"Houston Police Dept celebrates 40 years of air support"
. helihub.com. 18 November 2010
. Retrieved
28 February
2013
.
- ^
"Kansas City Police orders three new MD500Es"
. HeliHub.com. 20 February 2012
. Retrieved
3 December
2021
.
- ^
"MD Helicopters Delivers New MD 530F to Las Vegas Metro Police Department"
.
helis.com
. Retrieved
28 February
2013
.
- ^
"Police Department Aviation Unit | Nashville.gov"
.
www.nashville.gov
. Retrieved
2023-12-12
.
- ^
"Pasadena Police hold public launch of new 500E"
. helihub.com. 22 March 2010
. Retrieved
28 February
2013
.
- ^
"Prince George's County Police Department to Expand Aviation Section with new MD 520N - MD Helicopters"
.
www.mdhelicopters.com
. Retrieved
5 November
2019
.
- ^
"Aviation Division"
. Archived from
the original
on 21 July 2011
. Retrieved
28 February
2011
.
- ^
"ASTREA - Aerial Support to Regional Enforcement Agencies"
. sdsheriff.net
. Retrieved
28 February
2013
.
- ^
"Official Website of the Metropolitan Police Department, City of St. Louis"
.
www.slmpd.org
. Retrieved
6 July
2017
.
- ^
"Police Department | Law & Public Safety"
.
www.stlouisco.com
. St. Louis County
. Retrieved
7 July
2017
.
- ^
"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
.
- ^
"I Bought An Abandoned Helicopter From South America..."
YouTube
.
- ^
"MD500E Performance Specifications"
(PDF)
. Archived from
the original
(PDF)
on 22 January 2012.
- ^
a
b
Lednicer, David.
"The Incomplete Guide to Airfoil Usage"
.
m-selig.ae.illinois.edu
. Retrieved
16 April
2019
.
- ^
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
[
edit
]
External links
[
edit
]
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