
The AH-64D Longbow Apache is a remanufactured and upgraded version of the AH-64A Apache attack helicopter. The primary modifications to the Apache are the addition of a millimeter-wave Fire Control Radar (FCR) target acquisition system, the fire-and-forget Longbow Hellfire air-to-ground missile, updated T700-GE-701C engines, and a fully-integrated cockpit. In addition, the aircraft receives improved survivability, communications, and navigation capabilities. Most existing capabilities of the AH-64A Apache are retained.
The AH-64D is being fielded in two configurations. The full-up AH-64D includes all of the improvements listed above. In addition, a version of the AH-64D [formerly designated the AH-64C] without the FCR will be fielded. This version will not receive the new Radar Frequency Interferometer (RFI) or the improved engines, but will retain the other Longbow modifications. The AH-64D without FCR is capable of launching the Longbow Hellfire missile. Boeing delivered the first remanufactured Longbow Apache in March 1997. A total of 501 AH-64A Apaches are to be upgraded to the AH-64D configuration, 227 of which will be equipped with the FCR.

