HH-65 Dolphin Multi-Mission Helicopter, United States of America


MH-65 Dolphin helicopter

The Eurocopter HH-65 Dolphin is a twin-engine search and rescue (SAR) helicopter in service with the US Coast Guard (USCG). It is primarily used as a short range recovery (SRR) aircraft. It is a US version of the French-built Eurocopter SA366 G Dauphin.

The USCG operates 102 Dolphins from the Atlantic and Pacific Oceans, Gulf of Mexico, Hawaii and the Great Lakes regions.

The helicopters can perform a range of missions including search and rescue, smuggling prevention, homeland security, military preparation, ice breaking, marine environmental protection and pollution control missions.

Normally deployed from shore, the helicopters can also be operated from medium and high endurance USCG Cutters and Polar Icebreakers.

HH-65 Dolphin development

The Dolphin was originally manufactured by the Aerospatiale Helicopter Corporation (now American Eurocopter) in Grand Prairie, Texas. The USCG selected the helicopter to replace its Sikorsky HH-52A Sea Guard helicopter and designated it as HH-65A.

"HH-65 is powered by digitally controlled Turbomeca Arriel 2C2CG engines."

The maiden flight of HH-65A Dolphin was completed in July 1980. DGAC certification was awarded in July 1982. The first delivery was made to the USCG in November 1984.

In 2004, the USCG began the HH-65 conversion project to extend the service life of the helicopter until 2025. The project includes upgrades to 95 aircraft and acquisition of seven new helicopters.

The converted Dolphins are equipped with a modern, robust command, control, communications, intelligence, surveillance and reconnaissance suite and other new equipment. The upgraded HH-65s will be re-designated as Multi-Mission Cutter Helicopter (MCH).

HH-65 helicopter design

The HH-65 resembles the AS365 Dauphin, but incorporates new engines and modern avionics. The fuselage, rotor head and rotor blades are made of corrosion resistant, composite materials. A renowned feature of the HH-65 is its Fenestron tail rotor with 11 blades whirling within a circular housing positioned at the base of the tail fin.

The helicopter is certified for single-pilot instrument flight rules (IFR) operations. It is also the first helicopter certified with a four-axis autopilot, a unique ability that allows for steep approaches in zero-visibility conditions.

HH-65 variants

HH-65A was the initial USCG variant powered by two LTS101-750B-2 turboshafts, providing 547kW each.

The HH-65B is equipped with an upgraded avionics suite. The first HH-65B was rolled out from the post-depot maintenance facility in March 2001.

HH-65C is an improved version of HH-65A/B. It is fitted with new Arriel 2C2-CG engines, upgraded main and tail gearboxes, and a long-nose avionics compartment. The maximum take-off weight (MTOW) was increased to 4,300kg. It also received an expanded lateral flight envelope and vehicle and engine multi-function display. The first retrofit was completed in October 2004.

MH-65C Multi-Mission Cutter Helicopter (MCH) is a further advancement of the HH-65C. It comes with a new flight deck recovery system, transmission upgrades, a 10-blade low-noise tail rotor, a relocated avionics suite and digital autopilot equipment. The MTOW of MH-65C has been increased to 4,500kg.

MH-65D is fitted with an upgraded flight navigation system, digital global positioning system and inertial navigation systems.

Cockpit

The semi-glass cockpit can accommodate a crew of three including a pilot, a co-pilot and crewman / hoist operator. It features digital glass instruments similar to those found in the USCG's upgraded MH-60T Jayhawk medium range recovery helicopters.

"The maiden flight of HH-65A Dolphin was completed in July 1980."

The onboard NVG-compatible integrated flight management avionics suite incorporates two GPS-embedded CDU-900G control display units and two MFD-255 multifunction displays. The uninterrupted onboard communications are supported by dual UHF / VHF transceivers and single UHF / FM and HF systems, as well as a data link for automatic transmission of data.

Armament

The aircraft is armed with an M107-derived, 0.5 calibre, precision fire weapon and an M240B 7.62mm, general purpose machine gun.

Sensors / radars

The helicopter is equipped with enhanced radar and electro-optical / infrared sensors that provide common operational picture / maritime domain awareness data exchange capability.

Engines

HH-65 is powered by digitally controlled Turbomeca Arriel 2C2CG engines providing 40% more power than the initial LTS 101 engines.

Performance

HH-65 can fly at a maximum altitude of 15,000ft. It has a maximum speed of 165kt and a range of 356nm.