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| FY98 Annual Report | |||
AH-64D LONGBOW APACHE
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| Army ACAT IC Program: | Prime Contractor | |
| Total Number of Systems: | 758 | Boeing |
| Total Program Cost (TY$): | $6.7B | |
| Average Unit Cost (TY$): | $8.1M | Service Certified Y2K Compliant |
| Full-rate production: | 1QFY96 | No |
SYSTEM DESCRIPTION & CONTRIBUTION TO JOINT VISION 2010
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 without the FCR will be fielded. This version will not receive the new Radar Frequency Interferometer or the improved engines, but will retain the other Longbow modifications. The AH-64D without FCR is capable of launching the Longbow Hellfire missile.
All AH-64A Apaches in the fleet are to be upgraded to the AH-64D configuration: 227 will be equipped with the FCR, and the remaining 531 will not. Each attack helicopter company will receive three aircraft with FCRs and five without.
The mission of the attack helicopter is to conduct rear, close, and deep operations; deep precision strike; and provide armed reconnaissance and security when required in day, night, or adverse weather conditions. The AH-64D is a dominant maneuver platform that leverages information superiority and tactical precision engagement to provide full-dimensional protection for the ground maneuver force.
BACKGROUND INFORMATION
The combined Longbow Apache and Longbow Hellfire Initial Operational Test (IOT) was conducted in four phases: (1) gunnery; (2) force-on-force; (3) air transportability; and (4) aircraft conversion. The gunnery phase of IOT was conducted during January-February 1995 at the Naval Weapons Center, China Lake, CA. Testing conducted at Fort Hunter Liggett, CA, during March 1995, compared the Longbow Apache firing the Longbow and Semi-Active Laser missiles with the baseline AH-64A. The objectives of this phase were to assess the operational effectiveness of an attack helicopter company equipped with the Longbow weapon system relative to one equipped with the current AH-64A, and to assess the operational suitability of the aircraft. Both the test and baseline attack helicopter companies conducted missions against a battalion-size enemy force, augmented with formidable air defenses. A real-time casualty assessment system was used for kill removal. Air transportability and aircraft conversion demonstrations were also conducted at the contractor facility.
One issue uncovered during the IOT that required follow-on testing involved a method of employment for the Longbow Hellfire missile. During the IOT&E's force-on-force phase, Longbow Apache crews frequently overrode the system's automatic firing mode selection and fired missiles from a masked position using the Lock-On Before Launch Inhibit (LOBL-I) firing mode. This powerful technique significantly increased the helicopter's survivability during IOT&E, but had not been validated with live missile firings during the preceding DT/OT.
The DAB authorized full-rate production of the aircraft and radar in October 1995. The attendant Acquisition Decision Memorandum (ADM), dated October 18, 1995, required OSD approve the Army's plan to test the LOBL-I mode of engagement. The ADM also stated that testing would culminate with missile firings at moving targets.
TEST & EVALUATION ACTIVITY
OSD (DOT&E) worked with the Army to develop a plan for a Follow-On Test (FOT) of the LOBL-I firing technique to confirm system performance using this firing technique. The test program included all-digital simulations of the missile's target acquisition and fly-out, Hardware-in-the-Loop (HWIL) testing of the guidance section, low-speed captive flight tests (LSCFT) of the missile seeker, and live missile firings at moving armored vehicles. The LOBL-I FOT, conducted in accordance with the OSD approved plan, was a remarkably innovative use of modeling and simulation (M&S) in support of OT&E. In this instance, M&S was used to characterize the missile's performance in the LOBL-I mode in a far wider range of conditions than could be examined just using field testing. Factors such as target range and time delay (the time between locating the target and firing the missile) were varied based on what was observed during the IOT&E's force-on-force test results. Only after the M&S results were analyzed were informative cases selected for the LSCFT and the live fire missile shots. The results from the LSCFT and the missile firings were then compared to the M&S predictions to help further validate the simulation models. This was a noteworthy example of field test results (from the IOT&E) supporting M&S (digital, HWIL, and LSCFT), the results of which support field-testing (live missile shots). The first four shots of the scheduled eight-shot FOT were completed in November 1998. The service anticipates completing this FOT during 3QFY99.
TEST & EVALUATION ASSESSMENT
The IOT&E and LFT&E was conducted in accordance with the approved TEMP (September 1994). As reported to Congress in the October 1995 B-LRIP report, these tests were adequate to provide the information necessary to determine the system operationally effective, suitable, and survivable. Specifically, the AH-64D was found to be substantially more effective than the AH-64A in its IOT. During the gunnery phase, the AH-64D was able to acquire and effectively engage targets in obscuration that precluded engagement by the AH-64A. During force-on-force testing, the AH-64D force was significantly more lethal and survivable than the AH-64A force.
The Longbow Apache was also found to be suitable for fielding. The system met its reliability and maintainability requirements although several objectives were not achieved. AH-64D operational availability compared favorably with the AH-64A, although the system fell short of wartime availability objectives.
Taken in its entirety, the data from the digital and HWIL simulations, LSCFT and the missile firings, identified the key factors that significantly affect the missile's probability of acquiring and hitting the target when fired in the LOBL-I mode. These factors include target range, time delay (the time between locating the target and firing the missile) and target radial velocity (target speed and aspect angle). These emerging results do not alter DOT&E's assessment that the Longbow Apache is operationally effective, suitable, and survivable. The final results of this FOT could cause the Army to review AH-64D tactics, techniques, and procedures to reflect the "lessons learned" during this phase of testing.
LESSONS LEARNED
One issue uncovered during the IOT that required FOT involved the LOBL-I method of employment of the Longbow Hellfire missile. During the force-on-force phase, Longbow flight crews frequently elected to override the system's automatic mode selection logic and fire missiles from a masked position. This powerful technique significantly increased the helicopter's survivability, but had not been validated with live missile firings during DT/OT.
The Army's (PM Longbow Hellfire and Apache) approach to LOBL-I was a remarkable use of M&S to support OT&E. In this instance, M&S was used to characterize the missile's performance in the LOBL-I mode in a far wider range of conditions than could be examined just using field testing. Factors such as target range and time delay (the time between locating the target and firing the missile) were varied based on what was observed during the IOT&E's force-on-force test results. Only after the M&S results were analyzed were informative cases selected for the LSCFT and the live fire missile shots. The results from the LSCFT and the missile firings were then compared to the M&S predictions to help further validate the simulation models. Even though the LOBL-I FOT is not scheduled to be completed until 3QFY99, this approach to testing has been a noteworthy example of field test results (from the IOT&E) supporting M&S (digital, HWIL, and LSCFT), the results of which support field-testing live missile shots.
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