Development IRST Flies On Super Hornet

 - February 20, 2014, 11:34 AM
A test Super Hornet prepares to fly with the tank-mounted IRST sensor. The installation is cleaner than the first trials version flown in 2009. (Photo: Navair)

On February 11 a U.S. Navy Boeing F/A-18F Super Hornet made the type’s first flight equipped with an infrared search and track sensor. Developed by Lockheed Martin, the IRST sensor is intended to give the Block II Super Hornet and EA-18G Growler a long-range, passive detection and tracking capability against multiple air targets to augment the aircraft’s APG-79 AESA radar and other sensors. Fleet fielding is scheduled for 2017.

The program to provide an IRST for the Super Hornet began in 2007, when Boeing selected Lockheed Martin as its sensor partner. Faced with the problem of where to locate the sensor, the industrial team and the U.S. Navy Super Hornet program office, PMA-265, opted to mount it in the forward part of a modified centerline fuel tank to avoid costly airframe modifications and integration issues. The center and aft sections of the tank remain available for fuel carriage, and it can be jettisoned in emergencies.

By March 2009 Boeing had flown a trial installation of the IRST pod under a VX-23 F/A-18F on at least 10 occasions: six at Patuxent River, Maryland, and four at China Lake, California. In 2011 the program passed Milestone B and advanced into the $135 million EMD (engineering and manufacturing development) phase. As well as Boeing and Lockheed Martin, the industry team included GE Aviation for the fuel tank assembly and Meggitt Defense Systems for the environmental control system. Compared with the trial installation that was test-flown earlier, the latest version of the pod is aerodynamically cleaner, with a smoothly curved profile. There is a small airscoop for cooling on the upper portion of the pod’s nose.

Lockheed Martin’s IRST is a development of the AN/AAS-42 system that was originally carried by Northrop Grumman F-14D Tomcats. However, it has been undergoing development since then, first for the abortive pod-mounted system for the F-15 Eagle, and now further refined for the Super Hornet application.

Before the recent first flight in the Super Hornet, which was undertaken from Edwards AFB, California, the IRST system was tested in Boeing’s Beechcraft King Air testbed. Enabling elements of the system to be tested before more costly flight trials aboard the Super Hornet, the sensor was mounted in the nose of the King Air, while test engineers could test its functionality from stations in the cabin.