737 AEW&C Wedgetail Airborne Early Warning and Control Aircraft, USA

The Commonwealth of Australia placed a contract on Boeing in December 2000 for the development and supply of the 737 airborne early warning and control (AEW&C) programme, Project Wedgetail.

Boeing is the prime contractor for the program and team partners include Northrop Grumman's Electronics Sensors and Systems, Boeing Australia Limited and BAE Systems Australia.

The initial contract was for four AEW&C systems with options for up to three additional systems. The contract also provides a mission support segment and the associated ground based support segments for flight and mission crew training. In May 2004, Australia exercised options to purchase an additional two aircraft.

Boeing Australia is responsible for providing systems engineering and leading the product support teams. BAE Systems Australia is to supply the electronic support measures and the electronic warfare self-protection systems. Quantas Airways has been awarded the contract for maintenance of the aircraft. The first two aircraft will be completed by Boeing in the USA; the remainder will be modified in Australia.

The first airframe for modification was rolled out in December 2002, ready for modification and installation of the radar and systems. First flight of the aircraft with the radar and mission systems took place at the Boeing Field in Seattle in May 2004. Performance and flight handling tests were completed in July 2005. The first aircraft for modification in Australia arrived in January 2006.

Delivery of the first two aircraft, capable of peacekeeping and training roles to the Australian Air Force is planned for July 2009. These aircraft will then be upgraded to full mission capable status by January 2010. The remaining four aircraft will be delivered, fully mission capable, in early 2010. It is expected that the first aircraft will enter service with the Royal Australian Air Force's new Number 2 Squadron, with headquarters at Williamstown Air Base, by the end of 2010.

In May 2002, the Turkish government signed a contract with Boeing for four 737 AEW&C systems with options on a further two. The sale received US Government approval in September 2003. Boeing is modifying the first and Tusas Aerospace Industries (TAI) of Ankara the other three. The first aircraft for local modification arrived in March 2006.

Deliveries of the system, to be known as Peace Eagle, are expected by 2010. The first flight of the Peace Eagle was in September 2007. The first aircraft modified by TAI flew in July 2008.

In August 2006, the 737 AEW&C was selected as 'sole candidate' for South Korea's E-X requirement for four surveillance aircraft to be delivered by 2012. The contract was awarded to Boeing in November 2006.

Boeing 737-700 aircraft

The aircraft selected for the Wedgetail is the Boeing 737-700 increased gross weight variant (IGW), based on the airframe of the Boeing Business Jet. The aircraft is flown by two flight crew with between six and ten mission crew.

The aircraft operates at an altitude of 30, 000ft to 40,000ft with a maximum operating altitude of 41,000ft. The aircraft has state-of-the-art flight deck, avionics and navigation equipment. It has an extensive communications suite including three HF, eight VHF/UHF communications systems together with Link 4A and Link 11 systems.

Engines

The aircraft is equipped with two CFM International CFM56-7B24 engines each rated at 118kN. The aircraft's maximum take-off weight is 171,000lb (77,110kg). The range is 3,800 nautical miles and the time on station is estimated at more than nine hours.

The aircraft has a flying boom receptacle and a fixed probe providing dual in-flight refuelling capability

Mission avionics

The Advanced Systems Division of BAE Systems North America is to supply major elements of the aircraft's mission avionics, including cockpit tactical mission displays, command and control consoles and mission computers. There are six multi-role / multi-purpose mission consoles with ultra-high resolution flat panel tactical displays installed in the aircraft. Production of the equipment is scheduled to be carried out at BAE's Advanced Systems Greenlawn facility.

The computers use advanced signal processing algorithms to analyse, categorise and prioritise the data. The data is presented to the mission crew on an integrated situation display on the system console. The open system architecture ensures that the systems can be upgraded and extended. The AEW&C Wedgetail aircraft is compatible and interoperable with the E-3 and 767 AWACS airborne warning and control system aircraft.

The AEW&C Peace Eagle aircraft for Turkey are being fitted with EADS Defence Electronics multi-sensor integration software.

Radar

The MESA multi-role electronically scanned array radar is being supplied by Northrop Grumman Electronic Sensors and Systems Division, based in Baltimore. Tenix Defence Systems of Adelaide, Australia, is supplying some components and modules for the radar. MESA provides 360° coverage and a range of over 200nm.

The radar has a system track capability of 3,000 targets and can track air and sea targets simultaneously.

The system's variable track update rates and dedicated tracking modes allow the operator to track allied and hostile high performance aircraft while continuously scanning the area of operations.

The electronically scanned array features an assembly of transmit and receive modules, operating at L-band and sharing three apertures to provide the 360° coverage. The radar system provides a high level of operational capability because the system is dynamically structured to match the changing mission requirements. When an operator requires a long range view of a selected sector of the operational area, then the relevant system modes can be selected to initiate the search of that sector at more than twice the nominal uniform surveillance range.

An integrated identification friend or foe system (IFF) is combined with the primary radar and uses the same aperture as the primary radar, which avoids target correlation problems. The IFF system has an operational range of over 300nm.

The distinctive 'Top Hat' radome provides a low aerodynamic drag profile while meeting the requirement for fore and aft coverage. Two large strakes are fitted on the underside at the rear section of the fuselage. The strakes provide an aerodynamic balance to offset the effect of the MESA radome on the upper surface of the fuselage. In January 2005, flight tests of the aircraft were temporarily suspended while the upper surface of the radome was raised by about 100mm, to improve radar performance.

Countermeasures

BAE Systems Australia is responsible for the electronic warfare self protection and electronic support measures subsystems for the Wedgetail.

Elta Electronics of Israel has been selected to supply the advanced ESM/ELINT electronic support measures system.

The system provides 360º instantaneous surveillance and is similar to Elta ESM systems on RAAF P-3C Orion maritime patrol aircraft.

In February 2002, Northrop Grumman Electronic Sensors was awarded the contract to provide the AN/AAQ-24(V) Nemesis directional infrared countemeasures (DIRCM) system, augmented with the Viper solid state multiband laser.