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MD Helicopters MD Explorer |
By
Wikipedia,
the free encyclopedia,
http://en.wikipedia.org/wiki/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, Inc. There have been two models, the original MD 900, and its successor, the MD 902.
Design and development
The MD Explorer light twin helicopter is the first all new design to incorporate the unique NOTAR system. McDonnell Douglas Helicopters launched the Explorer as the MDX in January 1989. First flight took place on 18 December 1992. Full certification for the initial PW206B powered Explorer (unofficially designated MD 900) version was granted in December 1994.
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MD 900 (N900MH) Helicopter Noise Abatement Test |
One of the most advanced helicopters in its market segment, the MD Explorer features Boeing's unique NOTAR anti-torque system, with benefits including increased safety, far lower noise levels and performance and controllability enhancements. Instead of an anti-torque tail rotor, a fan exhaust is directed out 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 an advanced bearingless five blade main rotor with composite blades, plus carbonfibre construction tail and fuselage.
Initial Explorers were powered by two Pratt & Whitney Canada PW206As (the Explorer was the first application for the Pratt & Whitney Canada PW200 series), while plans to offer the Turbomeca Arrius as an option were dropped. 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 max takeoff weight. This enhanced Explorer was unofficially designated the MD 902.
From September 2000 the Explorer has been delivered with the further improved PW207E turboshaft, with improved hot and high and one engine inoperative performance.
In August 2008, 30 MD Explorers operating in the United Kingdom were grounded, on the orders of McDonnell Douglas, following an incident involving a London air ambulance.
Variants
- MD 900 Explorer
- Initial Production model, powered by two Pratt & Whitney Canada PW206A turboshaft engines.
- MD 901 Explorer
- Civil utility transport model, powered by two Turbomeca Arrius turboshaft engines. None ordered.
- MD 902
- High performance version.
- MH-90 Enforcer
- Armed version for the United States Coast Guard.
- Combat Explorer
- One demonstrator helicopter displayed at the 1995 Paris Air Show.
Operators
 Belgium
 Germany
 Luxembourg
 Mexico
 United Kingdom
 United States
Specifications (MD 902)General characteristics
- Crew: 1-2
- Capacity: 6 Passengers
- Length: 30 ft 10 in to 32 ft 2 in (9.4 m to 9.8 m)
- Rotor diameter: 33ft 10 in (10.3)
- Height: 8 ft 6 in - 11 ft 2 in (2.6 m - 3.4 m)
- Empty weight: 3,375 lb (1531 kg)
- Max takeoff weight: 6,500 lb (or 6,900 lb with external load) (2,948 kg)
- Powerplant: 2× Pratt & Whitney Canada PW207E turboshaft, 530 kW (710 shp) each
Performance
See also
Related development
Comparable aircraft
Related lists
External links
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Published in July 2009.
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