The Republic of South Korea Air Force is set to take possession of its first Airborne Early Warning & Control (AEW&C) aircraft in May of this year. The acquisition is governed by a 2006, $1.6 Billion deal with Boeing and Northrop Grumman in which 4 Boeing 737 derivatives will be delivered to the South Korean Air Force allowing it to field AWACS-type capabilities for the 21st century. The deal with South Korea involves Boeing, Northrop Grumman and Korea Aerospace Industries as major contractors in the program. Boeing is supplying the Boeing 373-700IGW (Increased Gross Weight) airframe on top of which the Northrop Grumman supplied MESA (Multi Role Electronically Scanned Array) antenna will be mounted. Significant integration and customization work is being undertaken on the 4 aircraft at KAI Sacheon facility near Seoul, before the delivery of the 3 final aircraft next year.
The 737-700IGW is a member of the NextGen Boeing 737 family of aircraft: an effort by Boeing to market a modernized version of the hugely successful ‘Classic’ series of Boeing 737 (-300/-400/-500 variants). The 737-700IGW is in fact commercialized as Boeing 737-700ER (Extended Range) in the airlines market. The aircraft is powered by 4 x CFM56-7 engines with 26,300 lb of thrust, has an operational ceiling of 41,000 feet with a range of 3,500 nautical miles (Boeing also offers a 737-700ER configured with 9 auxiliary fuel tanks and blended winglets allowing extended range of up to 5,775 nautical miles).
Development of the 737 AEW&C program was undertaken on behalf of the Air Force of Australia which had a requirement for 6 aircraft under the Wedgetail program with deliveries due to begin in 2006. Subsequently Turkey’s Peace Eagle program covering 4 aircraft and South Korea Peace Eye program also covering 4 aircraft were added to Boeing order book. Although each nation has issued specific requirements for their individual order, it appears nonetheless that Wedgetail, Peace Eagle and Peace Eye are almost similar systems. Each acquisition program entailed major integration work to be shared between Boeing ,Northrop Grumman and a major local subcontractor from the buyer’s nation. Boeing-Australia, Havelsan of Turkey and Korea Aerospace Industries were selected to carry integration and customization work on the Boeing supplied airframes.

Wedgetail and the MESA antenna
For the Royal Australian Air Force, the launch customer for the program Wedgetail provided the following benefits: a powerful integrated multi-sensor solution for airborne surveillance that could form a key component of Australia Network Centric doctrine well into the 21st century.
Wedgetail boasted the powerful Northrop Grumman supplied MESA antenna; a Multi-Role Electronically Scanned Array antenna. Mounted on top of the 737 fuselage, the 35 foot long and 6,000 pounds heavy MESA antenna operating on the L-band could provides instant Electronic Scanning agility to the Wedgetail radar out to 200 nautical mile detection range. Electronic scanning employing hundreds of high power transmit/receive solid state modules used a flexible beam for instant tracking capabilities across different pulse modes.The new antenna that covered a 360 degree field around the aircraft (lateral side arrays covering 130 degrees on each aircraft sides, forward and aft arrays covering each a 50 degree field in front and aft the aircraft) was a radical departure from the mechanically rotating AN/APY -1 and -2 dome antennas of the E-3 AWACS and E-2 Hawkeye and their 1 revolution per every 10 seconds.
In addition the Wedgetail system would integrate a modern suite of sensors into information that can be processed by the personnel on board or network to various theater assets. Boeing stated that The E-737 platform would provide data transmission for surveillance, air defense, maritime support, force coordination and civil support. The Multi sensor incorporation covered not only the Multi-Role Electronically Scanned Array (MESA) but other subsystems, sensors and features; IFF, ESM, EWSP, Link 11 & 16 networking.
-EWSP (Electronic Warfare Self Protection):Northrop grumman AN/AAQ-24(V) Nemesis DIRCM.
-DIRCM (Directed Infra Red Counter Measure)(Norhthrop Grumman):IR Countermeasures, Chaff Dispensers (radar countermeasures), Flare (pyrotechnics IR countermeasures)
-ESM (Electronic Support Measure) (AN/ALR series of passive detection systems for threat recognition of electromagnetic sources) employing the BAE Australia / Elta ALR-2001 ESM identifies radar threat
The on-board Local Area Networking architecture connected 10 tactical information processing stations using Components-Off-The-Shelf dual CPU with 8 GB of ram and 300 GB hard drives to process tactical information provided by multiple networked sensors.
Thus Wedgetail would provide an additional multi-sensor platform to generate, process and distribute tactical surveillance data along to Australia Vigilare multi-sensor network; a multiple data link network-centric management system integrating data from more than 45 sensors (including F-18 Super Hornet fighter jets) and information from defense agencies.

Wedgetail runs into trouble.
Although by March 2nd, 2006 one of the four Turkish 737 AEW&C aircraft had already the Northrop Grumman MESA antenna mounted to its fuselage. In addition by March 9th integrators had successfully completed ground testing of the MESA antenna key functions as well as integration of the IFF and Radar functions. However by June 29th 2006 a series of announcements by Boeing indicated that the program had ran into significant problems. An 18 months delay on planned delivery was incurred by Boeing although the manufacturer maintained that it could deliver the 6 Wedgetail planes during the year 2008. The manufacturer also accepted financial penalty between $300 million and $500 million from Australia. On March 20, 2007 subsequent simulated integration testing conducted aboard the aircraft had concluded that most systems could in fact operate concurrently without interfering with one another. The ESM subsystems however seemed to have remained an issue. It is only on May 5th 2010 that the Royal Australian Air Force officially accepted two 737 AEW&C aircraft at Williamtown RAAF base. But clearly the troubles were not over. The Wedgetail had not achieved IOC (Initial Operating Capabilities). The ESM subsystem integration issue has not been solved and Boeing embarrassingly delivered the 2 aircraft for the purpose of providing “Operational Flight Trainer, Operational Mission Simulator and Mission Support System” prior to delivery of final aircraft with final upgrade configuration for the ESM in 2011.
Growing frustrations with the program had led to Australian officials questioning the core capabilities of the 737 AEW&C program. Overall the Wedgetail program and its sibling Peace Eagle are likely to achieve Initial Operating Capabilities status during 2011 after much disappointment and embarrassment. The late but final achievement of operational capabilities would come to benefit hugely the South Korean Peace Eye program which has been financed at the time the Wedgetail was beginning to experience integration problems. As a result most of the engineering risks have been carried by Australia and Turkey.

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