Raytheon has defended its claim as the sole radar supplier for the US Air Force Boeing F-15 fleet, beating a rival bid by Northrop Grumman for the active array upgrade contract. On behalf of the USAF, Boeing selected the Raytheon APG-63(V)4 active electronically scanned array radar to upgrade the APG-70 for 179 USAF F-15Es.

The USAF is expected to award Boeing a contract in the fourth quarter of fiscal year 2008 to start the system development and demonstration (SDD) phase for the F-15 radar modernisation programme. Raytheon will build AESA radar test units during the SDD phase.

The APG-V(4) combines the front-end antenna of the APG-63(V)3 AESA and the back-end, dual-mode radar processor for the APG-79, which has entered service on the Boeing F/A-18E/F Super Hornet.

The USAF has requested $9 million to start the SDD phase in FY2008 and $75.4 million to continue development in FY2009, with the latter figure reduced by $50 million from the original plan.

The contract award is a disappointment for Northrop, which viewed its bid as a strategic opportunity to unseat its most significant rival on an incumbent programme.

The company offered a repackaged version of the APG-81 AESA being developed for the Lockheed Martin F-35 Joint Strike Fighter. Separately, it is designing a new active array radar for the Lockheed F-16, as the company seeks to defend its suddenly vulnerable monopoly on that fighter's main sensor equipment.

Northrop supplies the mechanically scanned APG-68 and the APG-80 agile beam radar for US and foreign F-16 customers, but its four-decade-old lock on the market has recently come under attack.

In July, Raytheon disclosed plans to offer a scaled-down version of the APG-79 active electronically scanned array, with the so-called Raytheon Next Generation Radar aimed at the single-engine fighter market, including the F-16, Korea Aerospace Industries/Lockheed T/A-50 and Saab Gripen (Flight International, 24-30 July).

James Pitts, president of Northrop's electronic systems sector, says the F-16 retrofit package is being designed to require no "group-A", or structural or wiring, modifications to the aircraft. The upgraded radar will include its own liquid-cooling heat exchanger that fits within the available space, he adds.

Lockheed officials have previously confirmed that they expect the US Air Force to eventually upgrade the F-16 radar to the AESA standard, and welcome a bidding competition between Northrop and Raytheon. Pitts also foresees the USAF as a potential customer, but views the export market as the most likely source of a launch order.

The F-15E radar modernisation programme is the latest in a wave of retrofit programmes involving AESA technology for fighter aircraft.

A subset of the USAF and Air National Guard F-15C fleets are now being upgraded to air-to-air versions of the APG-63 active array. Raytheon, meanwhile, is to produce the APG-79 for Block II Super Hornets, but may also retrofit the system on the Block I. It is not clear if the US Navy will reopen the retrofit contract for competition.

Source: Flight International