The McDonnell Douglas MD900 Explorer (also known as the MD Helicopters MD Explorer) is a twin-engine light utility helicopter featuring the innovative NOTAR (No Tail Rotor) anti-torque system. This design uses a fan-driven air circulation through the tail boom and directional thrusters for yaw control, resulting in quieter operation, improved safety near obstacles, and lower maintenance.
Brief History and Development
McDonnell Douglas Helicopters (later MD Helicopters) developed the MD900 in the late 1980s as the MDX program, based on extensive market research. It was one of the first helicopters designed entirely with computer-aided design (CAD) techniques. The prototype first flew on December 18, 1992. FAA certification was granted in December 1994, with first customer deliveries shortly after.
- The MD900 entered production with Pratt & Whitney Canada PW206 engines. An improved MD902 variant followed in the late 1990s with refinements in performance and systems.
- It has been used extensively in civil roles such as law enforcement, air medical/EMS, executive transport, news gathering, utility, and tourism. Production numbers are relatively modest compared to competitors, but the type remains in service with strong support for existing airframes.
- Ownership transitioned from McDonnell Douglas to Boeing and then to MD Helicopters.
Key model names:
- Civilian: MD900 Explorer, MD902 Explorer (improved version).
- Military/export: MH-90 Enforcer (U.S. Coast Guard armed interdiction variant, used briefly 1998–2000), Combat Explorer demonstrator (armed configuration with rockets/guns/FLIR).
Common Specifications (MD900/MD902 Explorer; varies by variant and configuration)
- Crew: 1–2 pilots.
- Capacity: 1–2 crew + up to 6 passengers (8 total in high-density config); internal payload ~2,565 lb (1,163 kg).
- Sling/external load capability: Up to 3,000 lb (1,361 kg) via optional cargo hook.
- Powerplant: 2 × Pratt & Whitney Canada PW206A/E (or Arrius in some early proposals) turboshafts (~550 shp each).
- Performance (approximate): Max speed ~140–150 kts (259 km/h); cruise ~130+ kts; range ~290–340 nmi (543+ km); service ceiling ~17,500 ft; excellent hover performance (IGE ~11,000 ft); low noise signature.
- Weights: Max takeoff ~6,250 lb (2,835 kg) internal / up to 6,900 lb (3,130 kg) with slung load; empty ~3,200–3,500 lb range.
Specs vary with altitude, temperature, and specific mission equipment (e.g., medical interiors or police gear).Specific Differences Between the MD900 (Civilian) and Military Versions (e.g., MH-90 Enforcer)The MH-90 Enforcer and Combat Explorer were militarized adaptations of the base MD900, with limited production/use.
- Equipment/Armament: Military versions could carry weapons (rockets, machine guns), FLIR/night vision systems, and mission sensors. Civilian models lack hardpoints and focus on utility/passenger configurations.
- Configuration: Military often featured tactical avionics, reinforced components, and specialized interiors (e.g., for interdiction). The MH-90 was used by the U.S. Coast Guard for drug interdiction from ships.
- Certification and Use: Civilian MD900/902 holds FAA/EASA certification for commercial operations. Military variants were operated under mil-specs or special approvals. Most operators today are civil or law enforcement (police versions are lightly equipped compared to true combat variants).
- Many military/demo airframes were later converted or returned to civil configuration.
Additional Interesting Facts
- NOTAR Advantages: The system eliminates the tail rotor’s hazards (especially in confined areas), reduces noise (beneficial for urban/police ops), and lowers maintenance by removing gearboxes and drive shafts.
- Quiet Operator: One of the quietest helicopters in its class, making it popular for law enforcement and noise-sensitive areas.
- Versatility: Strong in hot/high conditions; used for everything from executive shuttles and air ambulances to powerline patrol and aerial filming.
- Modern Status: While new production has been limited, existing MD900/902 airframes benefit from upgrades (e.g., increased gross weight approvals) and remain valued for their smooth ride and reliability.
The MD900 Explorer stands out as a technologically advanced light twin—emphasizing safety, low noise, and modern design in a market dominated by conventional tail-rotor helicopters. Its NOTAR innovation remains a distinctive feature appreciated by operators worldwide.
I was at the Royal Jubilee Hospital in Victoria, BC, Canada for some quick tests and I spotted this by accident while I was driving around looking for a parking spot.
Have a great day everyone!