UH-72A Lakota Light Utility Helicopter, USA

The UH-72A Lakota is the United States Army's new light utility helicopter. The UH-72A Lakota helicopters are being acquired to replace the UH-1H Iroquois and OH-58 A/C Kiowa helicopters. They will serve with the US Army mainly for logistics and support missions within the USA and also with the Army National Guard for homeland security and disaster-response missions.

The prime contractor for the UH-72A is EADS North America. A contract valued at $43.1m was awarded to EADS North America in June 2006 for an initial number of eight helicopters. The Army took delivery of the first UH-72A Lakota in December 2006 and deliveries of the initial eight were completed in July 2007. An additional 34 helicopters were ordered in October 2006 to be delivered by late 2008.

The Lakota entered service in June 2007. Full-rate production was authorised in August 2007. The US Army's requirement is for a total of 322 helicopters with a potential value of $2bn.

In October 2008, the US Navy placed an order for five Lakotas for training at the Naval Test Pilot School, Patuxent River, Maryland. Deliveries are scheduled for October 2009 to January 2010.

In December 2008, the US Army ordered a further 39 Lakotas, extending production to the end of 2010. Five more were ordered in February 2009, bringing the total confirmed order for the army to 128. The 50th was delivered in December 2008.

Sikorsky has been contracted to supply the UH-72A logistic support, including maintenance contract management, supply chain management, contractor field teams, spare part and tool management, facilities management and field and depot-level maintenance.

UH-72A design

The UH-72A light utility helicopter is a military version of the Eurocopter EC145. During the competitive bid phase, EADS North America used the UH-145 designation for its light utility helicopter entry. The helicopters are being manufactured by American Eurocopter at the company's production centre in Columbus, Mississippi.

The main and tail rotors are high set to allow fast and safe loading and unloading through the main doors and rear-fuselage clamshell doors even while the rotors are turning. The helicopter has a hingeless rotor system with composite main rotor blades which are 11m in diameter. The rotor configuration provides reduced noise and vibration characteristics. The high-set, twin-blade tail rotor has a diameter of 1.96m.

Safety features include a high level of redundancy with a twin-engine design, and redundant hydraulic, electrical and engine control systems. The crashworthy airframe and seats also contribute to the UH-72A's operational safety and survivability.

Cockpit

The cockpit and cabin are fitted with a large multi-piece wrap-around front windscreen, multiple side-fuselage windows on the cockpit and passenger doors, and side windows for the main cabin. The windows and windscreen, supplied by Nordam Group in Tulsa, Oklahoma, provide good visibility for the helicopter's crew and passengers.

The cockpit accommodates a crew of two and is fitted with two Simula energy-absorbing cockpit seats supplied by BAE Systems Mobility and Protection Systems (formerly Armor Holdings Aerospace and Defense Group) in Phoenix, Arizona. The cockpit seats have ergonomic cushions, a four-point restraint system with an inertia reel, and are qualified to FAA crashworthiness standards.

Avionics systems

The UH-72A is fitted with a night-vision-goggle-compatible glass cockpit with active matrix liquid crystal displays and a Meghas avionics suite supplied by Thales USA. The cockpit displays include the Thales centralised vehicle and engine management display (VEMD).

The cockpit displays simplify the presentation of flight and vehicle information, increasing the crew's situational awareness and reducing pilot workload. Production of the Meghas avionics suite is being transferred from Europe to a new Thales production facility in Irvine, California.

The helicopter's automatic flight control system is supplied by Sagem Avionics, Inc. and is partially produced at the company's Grand Prairie, Texas facility.

The UH-72A's automatic flight control system includes two attitude and heading reference systems (AHRS), advanced power management (APM) computers, smart electro-mechanical actuators, TRIM actuators and fibre-optic gyroscopes.

The avionics cooling system, supplied by Keith Products of Addison, Texas, ensures proper operating temperatures for the helicopter's navigation, communications and mission equipment.

Navigation and communications

The UH-72A helicopter's navigation and communications systems are supplied by Wulfsberg Electronics based in Prescott, Arizona. The navigation and air traffic control communications include dual VHF communications transceivers; dual VHF navigation receivers with VOR, ILS and marker beacon; and a DME transceiver.

The UH-72A's tactical communications system includes an RT-5000 wideband transceiver operating at 29MHz to 960MHz, and dual P-2000 tactical communications transceivers. Wulfsberg Electronics also supplies navigation and communications systems for EC145 helicopters used in civilian and special mission roles.

Cabin

The cabin accommodates eight troops or passengers. The cabin is fitted with BAE System's Simula passenger seats which are of fold-up design and meet FAA crashworthiness standards. The cockpit and passenger seats are of high strength lightweight composites construction and include aramid and graphite materials.

The cockpit and cabin are fitted with a heating and ventilating system supplied by Keith Products. The Keith Products heating, ventilation and cooling systems are fitted as standard equipment for all civilian EC145 versions of the Lakota UH-72A.

Mission systems

The modular design of the helicopter allows the fast and efficient installation of a range of mission modules.

For ambulance and medical evacuation missions, the cabin can accommodate two stretchers, plus one crew chief (who is qualified to operate the hoist and other aircraft equipment) and one medical attendant. The UH-72A's Nato standard stretchers and stretcher retainer mounts are supplied by Aerolite of Washington.

The helicopter has an externally mounted rescue electric hoist, series type 44301 from Goodrich Corporation. The hoist is mounted on a boom and support assembly that allows it to be positioned in an arc of up to 63° from the aircraft fuselage centerline for maximum operational flexibility. The hoist is stowed in line with the fuselage during flight.

Engines

The helicopter is powered by two Turbomeca Arriel 1E2 tuboshaft engines, each providing 550kW of take-off power and 516kW continuous power.

The engines are rated to provide a maximum power of 574kW for two and a half minutes and 404kW continuously in one-engine-inoperable-mode fight.

Flight training

CAE USA in Tampa, Florida has been contracted to design and manufacture UH-72A cockpit procedural trainers for the United States Army which will be used for procedural, familiarisation, and transition training as the army begins taking delivery of the UH-72A helicopters.

EADS North America is also acquiring the UH-72A cockpit procedural trainer to support pilot transition training, to be installed at the American Eurocopter training centre in Grand Prairie, Texas.