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	Director, Operational Test & Evaluation
	FY98 Annual Report

SYSTEM DESCRIPTION & CONTRIBUTION TO JOINT VISION 2010

The Radar System Improvement Program (RSIP) is a joint U.S., U.K., and NATO radar hardware and software upgrade for the E-3 Sentry Airborne Warning and Control System (AWACS). RSIP is designed to improve the E-3 radar detection capabilities in both benign and jamming environments, as well as enhance radar system reliability.

The mission of the E-3 AWACS is to provide land-based theater early warning, air surveillance, fighter control, and air battle superiority. The E-3 AWACS is a commercial Boeing 707-320C airframe modified with a distinctive radome that houses a pulse-Doppler radar capable of detecting aircraft and cruise missiles, particularly at low altitudes. In addition, the E-3 is equipped with general and specialized mission computers, multipurpose displays, and both clear and secure multiple-voice and data link communications. The United States acquired a total of 34 E-3s one of which is a dedicated test aircraft (Test System 3 a.k.a. TS-3) operated by Air Force Materiel Command at Boeing Field. One E-3 was lost in an accident. The remaining 32 E-3s are assigned to Air Combat Command. NATO, Great Britain, France, and Saudi Arabia also operate E-3s, each with different configurations than the U.S. aircraft.

The E-3 RSIP will enhance surveillance capability and provide air commanders with improved ability to observe, assess, and control the entire air battlespace, delivering information superiority to the dominant maneuver force as they engage the enemy. First deployed operationally in 1977, the E-3 has become the centerpiece of the theater air control system, performing early warning, air surveillance, combat identification, aircraft monitoring, fighter control, and battle direction missions. The AWACS has been employed in support of joint and multinational operations as part of the overall theater air control system and autonomously in advance of deployment of ground-based command and control systems.

Since initial fielding, the U.S. E-3 AWACS has nearly undergone continuous modification. Early modifications included adding a maritime ship radar detection capability, integrating first generation Class 1 Joint Tactical Information Distribution System (JTIDS) data link terminals, and increasing operator displays from 9 to 14 to support considerably broadened mission tasks and workloads. A significant number of modifications update mission systems, subsystems, flight controls and navigation software, and replace selective hardware components with more reliable parts. Block 30/35, the most recent system upgrade, adds a 360-degree-coverage passive Electronic Support Measures (ESM) system to support detection and identification; adds a Global Positioning System navigation capability; replaces the Class 1 JTIDS terminal with a Class 2H (High-Power Amplifier, modified) terminal; and adds memory capacity to the central mission computer to support ESM and JTIDS.

RSIP, the modification program currently on DOT&E oversight, replaces the aging AWACS radar subsystem computer, the Airborne Radar Technician workstation, other selected radar system hardware, and radar subsystem software, to improve pulse-Doppler radar sensitivity and resistance to electronic countermeasures, as well as increase reliability and maintainability of the modified components. The RSIP modification to increase the E-3's radar sensitivity, including the development of new waveform and processing algorithms, is planned to restore target tracking stand-off ranges delivered in 1977 that were decreased by the reduction in radar cross-section signatures of fighters and airborne cruise missiles. Improved E-3 reliability and availability are increasingly important as theater commanders continue to rely heavily on the E-3's surveillance and control capabilities to provide the information superiority required to control the battlespace.

The U.S. RSIP IOT&E started with its first sortie on August 3, 1995; and was suspended almost immediately when a mishap damaged the radar components. Investigation showed that the RSIP software did not have an automatic safety feature, which existed in the pre-RSIP software, to prevent power from going to the radar when a particular non-RSIP relay failed. The radar was repaired, the software was modified, and IOT&E resumed with the first sortie successfully completed on October 12, 1995. The scheduled six-sortie IOT&E was again suspended because of serious performance deficiencies observed during IOT&E. The IOT&E resumed for the third time in August 1996; and it was completed in October 1996. RSIP met operational performance requirements at that time; however, suitability issues remained.

Data from the U.S. IOT&E was augmented by system performance data gathered during NATO and U.K. tests/exercises, as well as a series of combined developmental/operational test flights. Piggybacking on previously planned activities reduced by approximately 40 percent the number of AWACS and test target sorties necessary to attain the required data. This approach also reduced test duration by approximately six months.

After the conclusion of IOT&E, the Air Force developed a post-IOT&E action plan to correct the suitability deficiencies highlighted by IOT&E. The plan primarily consisted of software improvements, but also included some hardware improvements. DOT&E monitored the testing of those improvements and analyzed the data. Post-IOT&E results verified significant improvements in RSIP suitability.

DOT&E has been actively involved in identifying test issues and reviewing data during FOT&E. IOT&E involved testing the RSIP-modified AN/APY-2 radar found in the TS-3 test aircraft and one-third of the USAF operational fleet. FOT&E will include the first testing of an RSIP-modified AN/APY-1 radar system. Two-thirds of the U.S. fleet are equipped with the AN/APY-1 radar. RSIP FOT&E will provide the opportunity to test a complete production-representative ESM system with RSIP.

The first FOT&E sortie took place April 8, 1998, using a pre-RSIP, APY-1 equipped E-3. This provided a performance baseline of the pre-RSIP APY-1 radar. The RSIP upgrade was installed on that same E-3 in September 1998, the first operational USAF E-3 to be RSIP equipped. The first acceptance flight occurred in October 1998. The remaining FOT&E sorties will be conducted when the E-3 modifications and acceptance flights are complete and the software is ready for FOT&E. The software redesign needed to resolve the remaining critical IOT&E deficiency, the RSIP impact to the Beyond-the-Horizon (BTH) radar, is of particular interest.

DOT&E analyzed the data from both U.S. and NATO IOT&Es, and also from combined DT/OT, including post-IOT&E testing. Testing confirmed that the RSIP-modified radar is capable of meeting the current system-level performance requirements and is substantially more effective than the pre-RSIP radar it is intended to upgrade. RSIP is capable of tracking smaller radar cross-section targets at longer range than its predecessor. RSIP is also far more effective when operating against electronic countermeasures.

The RSIP-modified radar provides significant improvements in several areas of suitability. The improvements in man-machine interface are a quantum leap forward from the previous system. Additionally, in-flight repair time, diagnostic effectiveness, fault detection, fault isolation, and built-in-test "cannot duplicate" rates were all system successes. Significantly, there have been no critical failures of RSIP hardware in 923 hours of flight-testing. However, the issue of software maturity plagued RSIP throughout testing. This is most evident in Mean Time Between Failure and Mean Time Between Critical Failure Rates, both of which fell well short of system goals. Despite this, the RSIP-only component break rate met requirements, and the overall radar break rate is comparable to the fleet break rate for 1996.

The only negative impact to current systems capabilities was to the BTH radar mode. While this degraded the ability of the U.S. crews to effectively use the BTH mode, NATO crews saw no difference. The cause of the change has been isolated to software. A corrective action plan is being executed to retune all BTH operating modes.

IOT&E and post-IOT&E testing indicate all critical concerns relating to integration of RSIP into the AN/APY-2 radar have been resolved with one exception: the action to correct the negative impact on the BTH radar range mode has yet to be verified. Additionally, since all testing was conducted on E-3s equipped with the second generation APY-2 radar, there was still a risk that RSIP, as currently designed, would not perform as required in the APY-1 equipped E-3s (the bulk of the USAF fleet).

The initial FOT&E sortie flown in April 1998 provided baseline target detection and radar performance data for the APY-1 equipped E-3. This aircraft will now be modified with the RSIP upgrades and used to complete the FOT&E scheduled in FY99. Data collected from the baseline sortie indicated normal detection ranges against targets of opportunity in all radar operation modes using both pulse-Doppler and BTH radar.

Baseline planning for FOT&E is complete, with the developer, user, and tester in agreement. DOT&E approved the FOT&E plan on April 1, 1998. Test and evaluation will concentrate on:

• Verifying whether RSIP as integrated into an APY-1 E-3, meets effectiveness and suitability requirements.



• Resolution of the BTH deficiency through assessment of long-range detection and tracking of air and maritime targets.



• Main mission computer and mission crew workload impacts when operating RSIP in conjunction with an operational ESM system in a realistic operational environment (planned to be completed in conjunction with a Red Flag or other Major Field Training Exercise).



• Software maturity.

Software maturity remains the highest risk item in the RSIP program. Regression testing has shown a higher than expected number of discrepancies resulting in a slip in the software delivery schedule of up to 20 weeks. This slip currently only impacts the NATO upgrade program. Further delay could impact the U.S. program schedule.

The AWACS Y2K program has completed awareness, assessment, renovation, and validation phases. A total of nine Y2K fixes have been implemented and tested. Most were relatively minor ground system date formats. The radar hardware and software do not use date codes; there are no RSIP or pre-RSIP Y2K issues. The prime contractor has submitted their final assessment report. A DoD Inspectors General audit concurred with the assessment and completeness of the AWACS Y2K program approach. The AFPOE/WS certified AWACS as Y2K compliant on November 19, 1998. AWACS will also participate in DoD-wide Y2K interoperability testing in 1999.

RSIP-modified E-3s consistently outperformed pre-RSIP AWACS in side-by-side testing in both initial long-range detection and continuous tracking. The side-by-side comparison was particularly useful in quantifying the increased detection capability resulting from the RSIP upgrade.

The OT effort produced a methodology to calculate expected detection ranges when radar cross-section densities are known. The methodology provides an empirically proven radar detection baseline for a variety of air targets. This was a first for the AWACS program and provides a useful method for predicting detection ranges of evolving threat targets.

Re-hosted radar software, combined with the new RSIP code, resulted in inadequate protection of aircraft radar hardware under certain operating conditions. Improved ground testing and design of new hardware interlocks were needed to ensure aircrew and aircraft safety. New procedures have been implemented to prevent further problems.

Software designed to ensure that RSIP met pulse-Doppler detection requirements inadvertently degraded the long-range detection and tracking performance of the BTH radar. This issue reinforced the need for thorough, ongoing compatibility testing for all system software changes.

Combining developmental and operational tests, as well as gathering test data from NATO and U.K. tests/exercises, significantly reduced test costs and duration. Future tests will use this same approach, leveraging existing activities wherever practical.

Agreements on test concepts and objectives during all phases of test must be thoroughly understood and documented. Key personnel changes in developer, user, and tester organizations resulted in intensive discussions to revalidate previously agreed to post-IOT&E and FOT&E test requirements. Possession of an updated TEMP and B-LRIP report identifying FOT&E issues and the outlining of a test strategy was instrumental in retaining the scope of testing during numerous personnel changes.