MD Helicopters MD Explorer

The MD Helicopters MD Explorer is a light twin utility helicopter. Designed in the early 1990s by McDonnell Douglas Helicopter Systems, it is currently produced by MD Helicopters. There have been two models, the original MD 900, and its successor, the MD 902.

MD Explorer
One of London's Air Ambulance's MD902 in 2008.
Role Light twin utility helicopter
Manufacturer McDonnell Douglas Helicopter Systems
MD Helicopters
First flight 18 December 1992
Introduction 1994
Retired 2000 (United States Coast Guard)
Status In service
Primary users Mexican Navy
Landespolizei
Luxembourg Air Rescue
Drug Enforcement Administration
Produced 1992–present

Design and development

In January 1989, McDonnell Douglas Helicopters officially launched the development of the Explorer, initially referred to as MDX. The Explorer was the first McDonnell Douglas helicopter to incorporate the NOTAR system from its initial design.[1] McDonnell Douglas partnered with Hawker de Havilland of Australia to manufacture the airframes. 10 prototypes were built with seven being used for ground tests. McDonnell Douglas Helicopters became a launch customer for Pratt & Whitney Canada's PW200 series of engines, with an exclusive agreement to power the first 128 Explorers with two PW206As.[2] Meanwhile, plans to offer the Turbomeca Arrius as an option were dropped.[1] The first flight of the Explorer took place on 18 December 1992, with ship #2 (N900MD). FAA certification for the Explorer was granted on 2 December 1994, with JAA certification following shortly after.

MD 900 (N900MH) Helicopter Noise Abatement Test

In September 1997, a range of improvements were introduced, including PW206E turboshafts with higher single engine inoperative ratings, revised engine air inlets, improved NOTAR inlet design and a more powerful stabiliser control system. Benefits include improved range and endurance and an increased maximum takeoff weight. This enhanced Explorer was unofficially designated the MD 902.

In September 2000, the Explorer has been delivered with the further improved PW207E turboshaft, with improved hot and high and one engine inoperative performance.[1]

The MD Explorer features the NOTAR anti-torque system, with benefits including increased safety, far lower noise levels and performance and controllability enhancements.[1] Instead of an anti-torque tail rotor, a fan exhaust is directed out of slots in the tail boom, using the Coandă effect for yaw control. Boeing retains the design rights to the NOTAR technology despite selling the former McDonnell Douglas civil helicopter line to MD Helicopters in early 1999. The Explorer also features a bearingless five blade main rotor with composite blades, plus carbonfibre construction tail and fuselage.[1]

Variants
MD 900 Explorer
Initial Production model, powered by two Pratt & Whitney Canada PW206A (or PW206E or PW207E) turboshaft engines.
MD 901 Explorer
Civil utility transport model, powered by two Turbomeca Arrius turboshaft engines and tri-angel landing gear. McDonnel Douglas Helicopters announced that this type was available from serial number 127 and upwards. By sale of civil helicopter variants to MD Helicopters the type was not further developed. None ordered.
MD 902
Marketing name for an enhanced version with Category A approval and powered by two Pratt & Whitney Canada PW206E or PW207E.[3] Enhanced version has additional engine isolation features and changes to the Integrated Instrument Display System.[3] Older helicopters (except for the first seven built) can be modified to the enhanced version.[3]
MH-90 Enforcer
Armed version for the United States Coast Guard flown by the Helicopter Interdiction Tactical Squadron from 1998 to 2000.
MD 969 Combat Explorer
Armed helicopter version[4]
Swift
A high-speed compound helicopter derived from the MD 969 being developed for the US Army’s Future Attack Reconnaissance Aircraft (FARA) program.[4] Excluded from FARA in 2019.[5]

Operators
A MD 900/902 of the Baden-Württemberg State Police
MD 900 operated by the National Park Service, based at Grand Canyon National Park
London's Air Ambulance operate two MD 902
 Belgium
 Germany
  • Landespolizei[7]
 Hungary
 Hong Kong
 Luxembourg
 Mexico
 United Kingdom
 United States
 Japan

Former operator
 United Kingdom
 United States

Specifications

Data from Jane's All The World's Aircraft 2003–2004[22]

General characteristics

  • Crew: 1–2
  • Capacity: 6 Passengers
  • Payload: 2,565 lb internal or 3,000 lb slung load (1,163 kg or 1,361 kg respectively)
  • Length: 32 ft 4 in (9.85 m)
  • Rotor diameter: 33 ft 10 in (10.31 m)
  • Height: 12 ft 0 in (3.66 m)
  • Disc area: 899.0 sq ft (83.52 m2)
  • Empty weight: 3,375 lb (1,531 kg)
  • Max. takeoff weight: 6,250 lb (2,835 kg) (internal load), 6,900 lb (3,129 kg) (slung load)
  • Powerplant: 2 × Pratt & Whitney Canada PW206E turboshaft, 550 shp (410 kW) (continuous) each

Performance

  • Cruise speed: 134 knots (154 mph, 248 km/h) at sea level (max. cruise)
  • Never exceed speed: 140 knots (161 mph, 259 km/h)
  • Range: 293 nmi (337 mi, 542 km) at 5,000 ft (1,500 m)
  • Endurance: 3 hr 12 min
  • Service ceiling: 17,500 ft (5,335 m)
  • Rate of climb: 1,000 ft/min (5.1 m/s)
  • Hover ceiling: 11,000 ft (3,400 m) (in ground effect, International Standard Atmosphere)
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See also

    Related development

    Aircraft of comparable role, configuration and era

    Related lists

    References
    1. Frawley, Gerard: The International Directory of Civil Aircraft, 2003-2004, page 156. Aerospace Publications Pty Ltd, 2003. ISBN 1-875671-58-7
    2. Warwick, Graham. "Rotorcraft Power: PW206A described.". Flight International. periodical. 13–19 July 1994. Retrieved on 11 October 2009.
    3. Federal Aviation Administration Type Certificate Data Sheet H19NM
    4. Reim, Garrett (March 6, 2019). "HAI: MD Helicopters developing winged MD902 as US Army scout". FlightGlobal. Reed Business Information Limited. Retrieved March 6, 2019.
    5. FaraSwift, Garrett (July 2, 2019). "HAI: MD Helicopters excluded from FARA scout". FlightGlobal. Rotary and Wing. Retrieved July 2, 2019.
    7. "Landespolizei MD 900". Retrieved 1 March 2013.
    8. "ORFK". index.hu. Retrieved 25 March 2016.
    9. "Heliservices About Us - MD902 Explorer". www.heliservices.com.hk. Archived from the original on 20 April 2015. Retrieved 24 March 2015.
    10. "Luxembourg Air Rescue - fleet". .lar.lu. Archived from the original on 4 March 2016. Retrieved 1 March 2013.
    11. "Grand Ducal Police LX-PGA". aeroboek.nl. Retrieved 1 March 2013.
    12. "MD902 serial MP-032 Mexican Navy". aeroflight.co.uk. Retrieved 1 March 2013.
    13. "Essex Air Ambulance G-EHAA". essexairambulance.uk.com. Retrieved 11 May 2015.
    14. "The Helicopter". London's Air Ambulance. Archived from the original on 24 July 2013. Retrieved 1 May 2013.
    15. "CalStar - Fleet". calstar.org. Retrieved 1 March 2013.
    16. "DEA N5646". aeroboek.nl. Retrieved 1 March 2013.
    17. "Helicopter Training Academy". nps.gov. Retrieved 1 March 2013.
    18. "Helicopter Service". mymuhealth.org. Retrieved 21 February 2014.
    19. Aero Asahi CORPORATION & CHIBA HOKUSHOH HOSPITAL ACHIEVE 10,000 HEMS MISSIONS EXCLUSIVELY BY MD 902 EXPLORER
    20. "Our helicopters". cornwallairambulancetrust.org. Retrieved 4 February 2018.
    21. "USCG MD900 Explorer". Retrieved 1 March 2013.
    22. Jackson 2003, pp. 679–680.
    • Jackson, Paul. Jane's All The World's Aircraft 2003–2004. Coulsdon, UK: Jane's Information Group, 2003. ISBN 0-7106-2537-5.
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