Radar plays large role in RSAF buyby Reuben F. Johnsonhttp://www.ainonline.com/Publications/asian/asian_04/d3_radarp20.htmlAn added dimension to the Singapore New-Generation Fighter competition is the greater than normal emphasis played by the radars fitted to the final three competing aircraft-the Dassault Rafale, the Boeing F-15T and the Eurofighter Typhoon.
Because of increased demands for performance, multirole capability and higher levels of reliability almost every major new fighter program in the world now is either already equipped with or has the near-term possibility to be retrofitted with an active electronically scanning array (AESA). Lockheed MartinÂ’s F-16 Block 60, F-35 Joint Strike Fighter (JSF) and the F/A-22 are all configured from day one with AESA sets developed by Northrop Grumman. BoeingÂ’s F/A-18E/F and the F-15 are both set to receive retrofits of AESA radars from Raytheon, and the Rafale is scheduled to have its current Thales RBE2 radar set, which currently employs a passive electronically scanning array, upgraded to an AESA variant once all the aircraft in service have all been modernized to the F3 configuration.
It is the situation with the latter two aircraft that is of prime significance to the Singapore competition. Thales has proposed its RBE2 AESA for the Republic of Singapore Air Force (RSAF). The Thales radar is close to being available for deployment, so depending on delivery schedules, Thales could deliver an AESA set on the second batch of aircraft to be delivered under the proposed contract schedule, and then the initial batch could be retrofitted to the AESA configuration.
Raytheon is offering an AESA version of the F-15’s radar, which would be the AN/APG-63(V)3. The Typhoon’s developmental program had called for the aircraft to receive its own AESA under Thales-BAE Systems joint development–the Airborne Multirole Solid State Active Array Radar (AMSAR) program–to replace its current BAE Systems ECR-90 Captor model, but this would not be earlier than 2010 and more realistic dates for a delivery would most likely be beyond this timeline.
Complicating the picture for the Typhoon are the consistent suggestions that there will be no Tranche 3 production run of the aircraft and that purchases of the aircraft would be truncated once the second batch is delivered, leaving the AESA development schedule as a question mark.
Thales has a model of the RBE2 AESA at the Dassault stand (No. A719), and Raytheon has a presentation of the APG-63 (V)3 on display (Stand No. A1412). RaytheonÂ’s model is based on the AN/APG-63(V)2 that was originally developed in 1999 under a formerly secret program for 18 U.S. Air Force F-15s based at Elmendorf AFB in Alaska. The newer (V)3 version that could be proposed for the RSAF has a redesigned antenna composed of a more advanced design of transmit/receive (T/R) modules.
But as much as both firms are vying for the Singapore contract, they also have to follow the lead of their customers back home. Raytheon, which expects to sell more than 160 F-15 radar retrofits to the USAF, did not bring a model of its AN/APG-63(V)3 design to Singapore as it was committed to the Air Force Association show in Orlando, Florida. The 20 aircraft for the RSAF are not enough of an order to justify the development cost otherwise.
Thales expects to either retrofit or deliver the entire 290-plus Rafales that are planned for production RBE2 AESA. However, even with delays in an order from the French air force, Thales have said that it could provide the AESA to the RSAF ahead of the timeline for its domestic customer.
For its part, Thales officials stress that to step up from the passive to the active model as they propose for the Rafale is much less complicated than what Raytheon proposes for the F-15. “Our upgrade is a replacement of the passive array with an active one plus some software and additional component swap-outs,” said a Thales representative. “The RBE2 radar was originally designed to eventually be upgraded to an AESA model so this antenna switch-out is more or less a plug and play proposition.”
Raytheon makes nearly identical claims about the AN/APG-63(V)3 stating that is mostly an antenna replacement and that the back end of the radar set remains much the same. “What has made the difference in the design of the (V)3 variant versus the previous (V)2 model has been the use of next-generation tiles in the T/R modules, a benefit that we enjoyed from the crossover of the technology we developed on the AN/APG-79 for the F/A-18E/F. This makes the (V)3 about 240 pounds lighter than the previous generation model,” stated one designer.
Although the (V)3 is not yet flying on an operational aircraft, Raytheon has the experience of the earlier generation (V)2 model on the F-15s flying now and that its USAF customer is quite pleased with the (V)2 variant. The (V)2 is such an improvement over the previous (V)1 mechanical array that “pilots fight for their turn to get into the cockpit,” said one Raytheon designer.
The Thales RBE2 AESA that would be supplied to the RSAF has been flying for more than 10 months and now it has been demonstrated for some senior RSAF officials. Thales enjoys an additional advantage in that as the sole source for the aircraftÂ’s entire radar, avionics and electronic warfare suite, the entire internal systems infrastructure is one integrated, open-architecture package. Future avionics upgrades or integration of new weapons can be accomplished with a minimum of time and expense.
The Singapore competition is really a look into the future in that the AESA radar is now the new cost of admission for a fighter trying to succeed in most export markets. A few years ago, the main question that customers wanted answered was, “Can I have an active-homing radar missile” (i.e., Raytheon’s AIM-120 AMRAAM or a European analog). Those sellers who said “no” were automatically at a disadvantage. Now in addition the new standard inquiry from a prospective customer is going to be, “How soon can I have an AESA?”