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Feature Report

'Wedgetail' in operational service

April this year marks two years since the first two Boeing 737-based Wedgetail Airborne Early Warning & Control aircraft entered service with the Australian Air Force - albeit without achieving full specified performance criteria. ...click here to read the full story.

	Feature Report - 'Wedgetail' in operational service

ABOVE: B737 'Wedgetail' AEW&C aircraft April this year marks two years since the first two Boeing 737-based Wedgetail Airborne Early Warning & Control aircraft entered service with the Australian Air Force - albeit without achieving full specified performance criteria. April this year marks two years since the first two Boeing 737-based Wedgetail Airborne Early Warning & Control aircraft entered service with the Australian Air Force - albeit without achieving full specified performance criteria. At the time, the platform had significant technical challenges, not least of which included: a shortfall in radar performance, problems with the Link 16 Data Link, and integration difficulties with the Electronic Support Measures systems. Fast forward two years, and Wedgetail is maturing into a very capable platform. Although there are still challenges ahead, there is real confidence within the Air Force that it will achieve Final Operational Capability by the end of this year, which is four years later than the original timetable. Both aircraft have participated in several 'high end' exercises, both at home and overseas, and the experience gained has fed into the development programme. The aircraft had been provisionally accepted by the Commonwealth in November 2009, although ownership was retained by Boeing, following a 'Standstill deed' in 2008 between the Commonwealth and Boeing, the prime contractor. This allowed for the provisional acceptance and continuation of development and testing, even though performance goals had not been met. In retrospect, the deed proved a watershed in the programme, with much progress made towards FOC. For the RAAF, Wedgetail is proving to be a key asset, and perhaps more significantly, AIr Force still regards it a developmental capability that will continue to improve in step with technology. To gain an understanding of how Wedgetail compares with the US Air Force's current AEW&C platform, the E-3C Sentry, the RAAF Wedgetail Program Director, Air Vice Marshal Chris Deeble says the newer 737 airframe is more reliable than the 707-based E-3, now long out of production. The E-3 radar is mechanically scanned and can transmit more power, but cannot dwell the way MESA radar can, he says. The ability to maintain 360 degree awareness and focus your attention on a given area simultaneously is significant. Wedgetail is also a more capable datalink platform, due to the amount of information we can gain organically off the aircraft, and with an expanded message set. It is estimated that the Wedgetail programme will deliver 98 per cent of the capability originally envisaged when it achieves FOC (against more than 10,000 individual requirements) and development will continue. Programme History The Boeing solution to Australia's Airborne Early Warning & Control capability requirement, nicknamed 'Wedgetail' was announced the winner of Project AIR 5077 in July 1999, beating proposals from Lockheed Martin (C-130J Hercules with upgraded AN/APS-145 radar) and Raytheon E-Systems (Airbus A310 with Elta radar). Based on the commercial Boeing 737-700 BBJ Increased Gross Weight (IGW) platform, Wedgetail's primary sensor is Northrop Grumman's L-Band Multi-role Electronically Scanned (MESA) radar in a 'Top Hat' or 'surfboard on the roof' antenna arrangement. The initial requirement was for seven aircraft, enough to operate 24 hours a day/seven days a week in two separate areas, but by the time of contract signature in December 2000, the number had been reduced to four aircraft and three options. An initial in-service date for the first two aircraft was set to occur in 2007, and by May 2004 the Commonwealth exercised its options for a further two aircraft, bringing the total to six. The first two aircraft were converted from 'green' 737s by Boeing in Seattle and the other four by Boeing Australia (Now Boeing Defence Australia) at RAAF Base Amberley. The first aircraft made its maiden flight after conversion in the United States from Boeing Field near Seattle in May 2004, and after initial aerodynamic testing began initial radar trials the following December. Boeing had high hopes for the MESA (Multi-role Electronically Scanned Array) radar, which was a leading-edge technology in radar design over previous mechanically operated radars. Although bench testing and simulation results were impressive, once fitted to the aircraft and tested under actual in-flight conditions radar performance shortfalls were immediately apparent, particularly with side-lobe issues, which affect the radar's ability to see through clutter and also have an impact on false alarm performance. This resulted in the redesign of the radar antenna 'Top Hat' section, but as testing progressed further problems became apparent, not least of which was its inability to achieve full power. By 2008 the programme was significantly behind schedule and the radar issues were such that the Massachusetts Institute of Technologys Lincoln Laboratories was engaged to audit the MESA system, in order to ascertain whether it could ever be developed enough to reach the original specification. MIT Lincoln determined that the architecture and hardware were sound and the radar was deemed, with software development, to have the potential for a successful growth path. Following the Standstill Deed, the Commonwealth engaged MIT Lincoln Labs, Boeing, Northrop Grumman, Australias Defence Science & Technology Organisation (DSTO) and US Government agencies to develop the radar further, although it accepted a degree of performance shortfall in the interim. Today, five Wedgetails are on the 2 Squadron flight-line at RAAF Base Williamtown, with the sixth due for delivery in the March/April timeframe. A further software drop will occur around that time, which will provide greater ESM and data link functionality as work towards FOC progresses. Current Status With five Wedgetails flying the RAAF has far greater certainty about the AEW&C platform than before. AVM Deeble, who has led the program since 2006 described progress over the past two years as gaining significant traction. He says the concept of incremental software improvement capability has helped Air Force to establish the final configuration. Last year was a significant year for software development including integration of a number of key systems, he said. The Electronic Support Measures system is coming of age after integration and software issues and we ended last year on a high. The software developed last year is on the aircraft and it continues to perform well. The final software upgrade prior to FOC will occur around the same time the final aircraft is delivered, in the March/April timeframe and then testing will be carried out up to FOC. MESA radar development and refinement is continuing, in conjunction with Northrop Grumman and Boeing, said AVM Deeble. The software development at the end of the year will meet the operational needs of the RAAF. The stability of the radar is now good. Its a very software-intensive system which has continued to improve through multiple software builds. We had some aspirational goals for the radar that are probably never going to be filled without the necessary understanding of MESA technology. It has good potential in the long term, but we will have to wait for processing technology to be developed. The radar sidelobe issues still need to be resolved, with collaboration work with MIT, Boeing and Northrop Grumman continuing. Some significant issues have been worked through with more robust information being transferred to the mission computer, says AVM Deeble. The details are classified, but we now do more with the radar itself. We are seeing earlier detection, earlier initiation of tracks and better track continuity. The radar is looking more holistically at targets on the threshold of detection. The two major shortcomings with the radar last year are almost resolved, with false alarm rates now to specification, and although clutter performance will just fall short it will be operationally acceptable by the end of the year. ESM is the last major sub-system to be fully integrated, and the RAAF has been working closely with BAE Systems Australia and Elta to improve stability and reliability. Although based upon the ESM system fitted to the AP-3C Orion, that fitted to Wedgetail is a much more complex system, a very significant step-function with much broader capability, AVM Deeble explained. Its ability to hoover up highly sensitive electronic emissions and fuse the data with the radar picture was always going to be a significant step. The Link 16 JTIDS/MIDS (Joint Tactical Information Distribution System/Multi-functional Information Distribution System) has also been problematic, but the Wedgetail configuration is one of the most complex integrations of any Link 16 system in the world. Boeing has really applied itself to get a stable and reliable system and certification of the data link will occur around April, AVM Deeble said. The next cut of software will be very close to the final configuration and will allow us to participate more holistically in exercises and within coalitions. AVM Deeble says he sees five hurdles ahead: Certification of the data links, further improvements in system stability, finalisation of ESM integration, the development of the ground segment, and finally, logistics support. The program had a lot of operators and engineers but not enough logisticians. Spares are an issue, says Deeble. We needed a bigger logistics statement up-front rather than leaving it right to the end and this has delayed the signing of the In-Service Support contract. Although expectations for Wedgetail have always been high, it is still a developmental concept, and is software intensive  a combination that has caused numerous recent defence projects to run late. The good news is that as technology develops, new fixes and improvements become available and, if the basic architecture is sound, the original specification may be met or, in some key areas, exceeded. Operational input to these issues is critical and the past two years have provided a great deal of information back to the project office, with Wedgetails concept of operations evolving. Some original specifications have been either superseded or are no longer relevant, thus its difficult to compare the aircrafts operational performance with the original requirements. Participation in major exercises has therefore been extremely valuable for the RAAF, which is able to constantly redefine its operational requirements, and for the project office as a measure of recent software upgrades. Wedgetail has now participated in a number of major exercises, including a RIMPAC exercise off Hawaii in 2010 and the recent Bersama Lima exercise in Malaysia in 2011. During Exercise Talisman Sabre last August, one aircraft forward-deployed to Tindal and although the ESM system was not mature enough to be tested operationally, significant radar and data-link work was undertaken. Such has been the level of radar stability, which had frequently required rebooting during previous exercises, the single aircraft flew all its assigned daily missions during Talisman Sabre, including one sortie of nine hours duration. This flight supported both the morning and afternoon waves of fighter combat and marked the longest Wedgetail sortie to that point. More importantly, the radar remained on-line for the entire duration and the data link provided a fused radar picture to other assets in the operational network. This operational test and development work will continue throughout this year and introduce further ESM integration in increments. One big test will be participation in Pitch Black, the ADFs premier Air Defence exercise, in July/August. Looking to the Future Beyond FOC, AIR 5077 Phase 4 (in the 2011 Defence Capability Plan but yet to be funded) will be a research and development agreement with Northrop Grumman to keep the MESA radar updated through its life. Looking further into the future, AIR 5077 Phase 5 will be developed as a block upgrade programme. According to AVM Deeble, an upgrade cycle is critical to guarantee interoperability into the future. As far as radar development is concerned, he says stretching the range of the Identification Friend or Foe (IFF) system is also being studied. The 737 AEW&CF platform is now entering service with the air forces of South Korea and Turkey, and a 737 element of the US-led AEW&C and AWACS forum will allow collaboration on MESA development. AVM Deeble says DSTO projections show that MESA will exceed specification in the future, which is encouraging. Later this year, for the first time, you will see an AEW&C configuration with the ability to fuse data and transmit that fused picture through data links to other users, he concludes. We have seen a most successful collaboration on radar improvement, collaboration despite losses by industry partners and some very difficult commercial negotiations. The next challenge will be obtaining funding to keep it interoperable and maintain it at the cutting edge. Below: Crews walk for a sortie with the 'Wedgetail' Airborne Early Warning & Control aircraft. (Defence).