Northrop Grumman Corp. has begun structural testing of the antenna for its Multirole Electronically Scanned Array (MESA) radar, which the company is producing under contract to The Boeing Co. for the Australian Defence Force's Wedgetail airborne early warning and control aircraft.

The antenna is an innovative aperture that provides a 360° azimuth scan with no mechanical rotation. Attached to the top aft section of the fuselage, it consists of an advanced composite structure that supports side-emitting electronic manifold arrays and a 'top hat' end-fire array. Its ultralight construction enables state-of-the-art performance at a fraction of current system weights, thereby allowing additional time on station for the aircraft.

MESA will provide multiple surveillance applications, using pulse Doppler radar forms for air search and pulse forms for maritime surface search. It will also provide, in the same aperture, an integrated civil and military identification friend-or-foe capability.

The 14-month test program is designed to demonstrate compliance with both the static and dynamic strength and fatigue requirements for safety certification by the US Federal Aviation Administration. Limit loads will be placed on the antenna in order to stress the structure to the design limits that will be encountered by the airframe, a modified Boeing 737-700.

The dynamic testing will simulate 200,000 flight hours. Data reduction and analysis will be completed before the first flight of a MESA-equipped 737, which is scheduled to take place during the second quarter of 2004. The first phase of testing, for static loads, will be completed by June 2003, with the dynamic phase scheduled for completion by April 2004.