The U.S. Navy has disclosed a new feature added to a secretive radar designed for the P-8A fleet that allows the sensor a full field of view unobstructed by the aircraft’s engines.
The Raytheon Advanced Airborne Sensor (AAS) integrates a radar with ground moving target indication and synthetic aperture radar modes to the P-8A’s passel of onboard sensors, serving a function similar to the APY-7 radar on the Air Force’s E-8C J-Stars. The AAS replaces the Raytheon APS-149 Littoral Surveillance Radar System installed on the P-3C.
The Navy has released few details about the performance and fielding schedule for the AAS on the P-8A fleet.
Nearly all of the information about the program has been disclosed by the release of “sources sought” notices for the AAS or related items.
Naval Air Systems Command released such a sources-sought notice on July 12 for companies that could provide a trainer for a part called the forward deployment mechanism (FDM) on the special mission pod deployment mechanism (SMPDM) for the P-8A.
The notice describes the SMPDM as a hydraulically activated system that allows the AAS to extend several inches below its mounting point on the belly of the P-8A fuselage. The extension allows the AAS to descend beneath the obstruction caused by the nacelles of the CFM56 high-bypass turbofan engines mounted on both wings of the P-8A. The SMPDM also retracts the radar pod after the mission is completed to its stowed position on the belly of the aircraft.
Such a capability is useful in an era of military derivatives of commercial aircraft powered by high-bypass turbofans with large-diameter fans. The E-8C, by contrast, is derived from the Boeing 707, which uses smaller turbofans for propulsion and may not pose as much of an obstruction to a belly-mounted sensor.
The Navy released the notice to identify sources that could provide functional hardware trainers for the FDM, a linkage system with springs and hydraulic actuators that causes the SMPDM to extend and retract.