Radar plays large role in RSAF buy
by Reuben F. Johnson
http://www.ainonline.com/Publications/asian/asian_04/d3_radarp20.html
An 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 Martins 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. Boeings 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-15s radar, which
would be the AN/APG-63(V)3. The Typhoons developmental program had
called for the aircraft to receive its own AESA under Thales-BAE
Systems joint developmentthe Airborne Multirole Solid State Active
Array Radar (AMSAR) programto 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). Raytheons 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 aircrafts 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., Raytheons 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?
