TYPE: Airborne early warning and control system.

PROGRAMME: Adaptation of Boeing Business Jet (BBJ, which combines 737-700 fuselage with strengthened wing and landing gear of 737-800). Additional features include extra fuel tanks in former baggage hold. Proposed for Australian Project Air 5077 Wedgetail by Boeing, Northrop Grumman Electronic Sensor Systems Division (ESSD) and BAE Australia. Competed against proposals from Lockheed Martin and Raytheon. Secured initial design activity contract worth about US$6 million in December 1997, paving way for submission of full tenders in early 1999. Selection of Boeing submission officially announced on 21 July 1999. RAAF initially planned to acquire seven aircraft for US$1.32 billion; cost concerns resulted in reduction to six plus one option in May 2000, but when contract signed on 20 December, this had further reduced to four and three options, at reported cost of US$1.65 billion. Delivery of first two aircraft scheduled for the end of 2006, with operating unit to be No. 2 Squadron. Second pair to be handed over at end of 2007. Main base at Williamtown, New South Wales, with two aircraft permanently deployed to forward operating location at Tindal, Northern Territories; IOC to be achieved at end of 2008. Preliminary design review of radar and IFF systems successfully completed in September 2001; further reviews of navigation system, mission computing hardware and other airborne mission systems undertaken by January 2002, with ground-based elements not scheduled to undergo PDR until 2004.
ESSD L-band multirole electronically scanned array (MESA) radar mounted above rear fuselage ('top hat' configuration) providing 360° coverage from stationary antenna 10.7 m (35 ft) long and 2.35 m (7 ft 9 in) high. Operating modes will include acute long-range or broad short-range scanning and track-while-scan; maximum detection range said to exceed 216 n miles (400 km; 249 miles). Initial radar to be installed in Boeing 737 in 2003 for testing, with modification of this and remaining three aircraft to be undertaken in Wichita, Kansas. In late 1998, demonstrator BBJ temporarily fitted with full-scale replica of MESA radar, six operator consoles and equipment cabinets for inspection by Australian defence department officials; mockup also featured in-flight refuelling probe above cockpit and EW/ECM sensors. Definitive aircraft will, however, feature 10 operator consoles initially, with potential to add further two. Aerodynamic effects of MESA offset by two large strakes below rear fuselage. Electronic warfare self-protection (EWSP) system will include Northrop Grumman AN/AAQ-24(V) directed infra-red countermeasures system, plus chaff and flares; Elta providing advanced ESM/elint systems; these will be controlled by the ALR-2001 computer. Other mission equipment to include Link 11, JTIDS, Mode S IFF and satcom; flight deck tactical displays, three HF and eight VHF/UHF radios. Patrol endurance of 9 hours at 300 n miles (555 km; 345 miles) from base can be extended by airborne refuelling, with modification to include installation of flying boom receptacle and a removable probe. Maximum T-O weight 77,565 kg (171,000 lb); service ceiling 12,500 m (41,000 ft).
First Australian aircraft rolled out at Seattle on 31 October 2002; subsequently, flown to Georgetown, Delaware, on 4 January 2003 for installation of an auxiliary fuel system and tanks. Latter procedure should require about three months to complete, whereupon aircraft was due to return to Boeing for structural modifications associated with installation of radar and mission systems. First MESA radar rolled out at beginning of November 2002 and installed on test range by Northrop Grumman; delivery to Boeing for installation on 737 was expected in May 2003, with first flight due in early 2004.
Republic of Korea interested in AEW-configured 737 as less costly solution to E-X requirement in lieu of Boeing 767, which considered too expensive; Boeing proposal in competition with rival offerings from Raytheon and Thales, both of which have Airbus A321 as platform. Total of four aircraft required by Korea, which is expected to announce winner in 2005.
After studying proposals for AEW aircraft involving Airbus A310/Phalcon and Boeing 737/MESA combinations, in early December 2000 Turkey announced selection of latter and revealed intent to obtain total of six aircraft (with option on two more) at cost of US$1.5 billion; these will include some indigenous equipment. Contract signature was expected in early 2001, but negotiations continued throughout remainder of 2001; contract finally signed on 4 June 2002, at which time the number of aircraft to be purchased had been reduced to four (with two on option).
Boeing originally forecasting potential sales of up to 50 737AEW&C aircraft, with other possible customers including Italy, Singapore, Spain and the United Arab Emirates; by the beginning of 2002, this had fallen to 30 over next 10 years.