MH-90 Enforcer

The MH-90 Enforcer underwent evaluation as part of the USCG's experiment with armed helicopters. With its NOTAR (No Tail Rotor) design, is very easy to operate from the small flight decks of the Medium Endurance Cutters. The MH-90 is based on the McDonnell Douglas twin-turbine MD 900 Explorer, modified for air-sea rescue and police work. With the largest functional cabin in its light-twin class, the MD Explorer's cabin size equals that of medium-twin class helicopters. Integrated optional avionic systems are easily accessible. Large 52-inch (1.32 m) cabin door openings on both sides of aircraft allow unrestricted ingress/egress.

Beginning in March 1999, the Coast Guard deployed a pair of armed MH-90s for operations from USCG Medium Endurance Cutters. Following a six-month operational evaluation, the original two MH-90s were returned to the factory for refit and upgrades. At that time, two additional MH-90s were leased by the USCG for continued evaluation. The MH-90s are equipped with a variety of lethal and non-lethal weapons. The main armament of the MH-90s consists of a M240G machine gun coupled with a 50-caliber sniper rifle equipped with a laser sight. The machine gun's primary purpose is to fire warning shots across the path of fleeing go-fasts, while the sniper rifle is used to selectively target and disable the engines of the go-fasts as necessary. Other non-lethal armament consists of stun grenades and entangling nets among other pieces of equipment.

The MH-90s are also equipped with armor plating, a camera system mounted on a gyro-stablilzed fitting, a night-vision compatible cockpit, a GPS-based navigation system, and Forward-looking InfraRed (FLIR). In addition, a deployable flotation system has been fitted due to the units operations over open water. The communications suite of the MH-90 includes HF/VHF/UHF radios capable of operating in both the secure and clear modes.

The U. S. Coast Guard announced 15 March 2000 the successful completion of the final evaluation of its latest tactic in the war on drugs: the airborne and high-speed smallboat use of force against narco-smugglers in "go-fast" boats. The Coast Guard created "Operation New Frontier" (first announced in September 1999) to employ the use of armed helicopters and high-speed smallboats to stop small, high-speed smuggling vessels, known as "go-fasts," which carry narcotics bound for the United States. Before Operation New Frontier, law enforcement officials said the Coast Guard was only able to stop one in 10 go-fasts because it was simply being outrun by the bad guys.

The new assets were developed to level the playing field and force smugglers to take notice. The helicopters deploy state-of-the-art, non-lethal weapons like sting grenades and nets to stop these fleeing vessels. The latest deployments for the Enforcer and the over-the-horizon deployable pursuit boats expanded initial operations to include enhanced capabilities, such as nighttime operations. Of the six vessels detected by Operation New Frontier, all six were successfully captured. In fiscal 1999, the $10 million investment in this program returned $120 million in seized drugs.

In less than a year and a half, the project to acquire these new drug busters went from concept to operational testing. Based on the positive evaluation, a new permanent squadron of these aircraft and smallboats was established in Jacksonville, Fla.

The speed and relative stealth of the helicopter allows for covert surveillance and tracking of a variety of surface targets. The MH-90 is much quieter than normal USCG helicopters due to its NOTAR design.

The Hughes MD 520N was the world's first production model helicopter whose yaw control system is based on an air outlet at the tail instead of a tail rotor. The NOTAR® (no tail rotor) concept, using compressed air to offset torque instead of a conventional tail rotor, was pioneered in the MD-520N. A NOTAR version of the heavy-lift Model 530 became the MD-530N. McDonnell Douglas pioneered the concept of a system called NOTAR (for NO TAil Rotor) which eliminates the dangerous and complex tail rotor system used in conventional helicopters. In the NOTAR system a variable-pitch axial fan is located at the front of the tail boom to drive air through the boom. There it exhausts through slots along the boom to produce a Coanda effect which produces torque to counteract that caused by the helicopter's main rotor. The NOTAR system simplifies helicopter tail assemblies thereby improving reliability and reducing maintenance requirements. Pilot loading reduces because the pilot does not have to account for tail rotor inertial effects.

On 12 February 1998 the Boeing Company announced its intention to sell its commercial helicopter business. Boeing built commercial helicopters -- the MD 500 Series, MD 600, and MD Explorer -- in Mesa, Ariz., where it also produces the AH-64D Apache Longbow. On 19 January 1999 McDonnell Douglas Helicopter Co., the indirect subsidiary of The Boeing Company, and MD Helicopters Holding, Inc., an indirect subsidiary of the Dutch company RDM Holding, Inc., signed an agreement on an asset purchase of Boeing's MD 500, MD 600N® and MD Explorer® series of light commercial helicopter product lines. Included in the product line are the MD 500E and MD 530F® single-engine helicopters with conventional tail rotors, the MD 520N® and MD 600N single-engine helicopters with Boeing's exclusive NOTAR® no tail rotor system for anti-torque and directional control, and the MD 900 Explorer series of twin-engine, eight-place helicopters.