University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 5-2005 The Evaluation of the Low Probability of Intercept Altimeter (LPIA) and its Impact on EA-6B Operations Daniel Philip Covelli University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Aerospace Engineering Commons Recommended Citation Covelli, Daniel Philip, "The Evaluation of the Low Probability of Intercept Altimeter (LPIA) and its Impact on EA-6B Operations. " Master's Thesis, University of Tennessee, 2005. https://trace.tennessee.edu/utk_gradthes/1860 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Daniel Philip Covelli entitled "The Evaluation of the Low Probability of Intercept Altimeter (LPIA) and its Impact on EA-6B Operations." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Aviation Systems. Robert Richards, Major Professor We have read this thesis and recommend its acceptance: U. Peter Solies, Charles T. N. Paludan Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a thesis written by Daniel Philip Covelli entitled “The Evaluation of the Low Probability of Intercept Altimeter (LPIA) and its Impact on EA- 6B Operations.” I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Master of Science, with a major in Aviation Systems. Robert Richards llllllllllllllll Major Professor We have read this thesis and recommend its acceptance: U. Peter Solies lllllllllllllllllllll Charles T. N. Paludan lllllllllll Accepted for the Council: Anne Mayhew llllllllllllllll Vice Chancellor and Dean of Graduate Studies (Original signatures on file with official student records.) THE EVALUATION OF THE LOW PROBABILITY OF INTERCEPT ALTIMETER (LPIA) AND ITS IMPACT ON EA-6B OPERATIONS A Thesis Presented for the Master of Science Degree University of Tennessee, Knoxville Daniel Philip Covelli May 2005 DEDICATION This thesis is dedicated to my father, Daniel Frank Covelli who passed away on January 24, 2005 at the age of 67 after a horrific battle with cancer and to my wife, Jacqueline, son, Tyler and mother, Lucille who have supported me every step of the way while waiting patiently for me to finish this endeavor. ii ACKNOWLEDGMENTS I would like to thank everyone involved in helping me write this thesis in order to complete my Master of Science degree in Aviation Systems. In particularly I would like to thank Dr. Bob Richards for all of his time and effort. I would like to thank Betsy Harbin and the rest of the support staff at the University of Tennessee for all their help while participating in the Aviation Systems Program. In addition, I would like to thank the entire EA-6B LPIA Test Team for their hard work and steadfast dedication to the project during its developmental testing phase. iii ABSTRACT The purpose of this study was to evaluate the performance of the Low Probability of Intercept Altimeter (LPIA) Radar Altimeter (RADALT), which was selected to replace the AN/APN-194 RADALT, as installed in the EA-6B Prowler and conclude how the new system will impact the tactical operation of the EA-6B aircraft if allowed to proceed to and pass the operational phase of testing in its current status. The LPIA was selected to replace the APN-194 as part of the overall EA-6B aircraft Block III test program in order to comply with the Chief of Naval Operations’ (CNO’s) mandate to install the Ground Proximity Warning System (GPWS) in all U. S. Navy tactical aircraft. Although other options were initially available, Program Manager Aviation (PMA)-209, the avionics program manager, insisted LPIA be used and classified the equipment as “off-the-shelf.” They believed it would require minimal testing since it had already been successfully tested and installed in two other fleet platforms (P-3 and C-2). No mention was made of the problems discovered or the failed attempt to integrate the system into the F/A-18 Hornet and S-3 Viking aircraft. The initial evaluation was originally scheduled for approximately 12 flight hours, however two test analyze fix periods of that magnitude have already been conducted on the LPIA and several deficiencies have been discovered. Currently, in the opinion of the author, the LPIA is unsuitable to support the EA-6B’s mission needs. PMA-234, the EA- 6B Program Manager has decided to give British Aerospace Engineering (BAE), the prime contractor, and PMA-209 one more opportunity to fix the deficiencies prior to the start of Block III flight test. iv The author concludes that if the LPIA is allowed to proceed in its current condition and is introduced to the fleet, it would have detrimental effects on the EA-6B’s operational capability. If the system fails developmental testing (DT), an alternate means to supply height above the terrain to GPWS will have to be explored. The author recommends specific improvements, which may produce an effective system that is suitable for EA-6B operations. v PREFACE Information contained in this thesis was obtained from Department of Defense reports and manuals and product literature from British Aerospace Engineering (BAE) Systems and DCS Corporation. Any conclusions or opinions presented within this document are the opinion of the author and should not be interpreted as that of the United States Navy or the University of Tennessee Space Institute. vi TABLE OF CONTENTS CHAPTER 1: INTRODUCTION …………………………………..…………....1 OVERVIEW……………………………………………………………….. 1 GENERAL …………………………………………………………. 1 SPECIFIC ………………………………………………………….. 2 STATEMENT OF PROBLEM……………………………………………..2 CHAPTER 2: BACKGROUND …………………………………………………..4 EA-6B MISSION…………………………………………………………...4 AIRCRAFT DESCRIPTION……………………………………………….4 CURRENT PROGRAMS…………………………………………………..6 LEGACY RADAR ALTIMETER (AN/APN-194) SYSTEM DESCRIPTION……………………………………………………………..7 AN/APN-194 RADAR ALTIMETER ………………...…...………7 RADAR ALTITUDE INDICATOR …………………………..…… 7 LOW ALTITUDE WARNING SYSTEM TONE …………………. 9 LOW ALT WARNING LIGHT …………………………………… 10 LPIA SYSTEM DESCRIPTION…………………………………………...10 LOW PROBABILITY OF INTERCEPT ALTIMETER …………...10 Jamming Resistance …………………………………….…13 Built-In-Test ………………………………………………. 13 CONTROL DISPLAY NAVIGATION UNIT – 900A …..…….….. 14 LPIA HISTORY…………………………………………………………… 17 CHAPTER 3: SYSTEM EVALUATION ………………………………………. 19 GENERAL…………………………………………………………………. 19 SCOPE OF TESTS………………………………………………………… 19 TEST ENVELOPE………………………………………………………… 20 CONFIGURATIONS……………………………………………………… 21 DATA COLLECTION…………………………………………………….. 21 LIMITATION TO SCOPE………………………………………………… 22 TEST EVENTS…………………………………………………………….. 22 GROUND TESTS ……………………………..…………………… 23 Fit Check … ……………………………..………………… 23 Crew Interface …………………………………..………… 23 Auto-Calibration ………………………………………….. 24 FLIGHT TESTS …………………………………………………… 24 Monitored Range Evaluation …………………………….. 24 Jammer Evaluation ………………………………………. 26 Low-Level Evaluation ……………………………………. 27 Landing Pattern E valuation ……………………………... 27 CHAPTER 4: RESULTS ………………………………………………………… 29 GENERAL…………………………………………………………………. 29 GROUND TESTS…………………………………………………………. 29 CDNU BIT …………………………………………………………. 29 AUTO-CALIBRATION …………………………………………… 32 vii FLIGHT TESTS…………………………………………………………… 32 HEIGHT INDICATOR LAG ……………………………………… 32 STANDBY TO TRACK TRANSITION TIMES ………………….. 37 MAXIMUM ALTITUDE RANGE ……………………………...… 39 ALTITUDE UPDATE RATE ……………………………………… 39 FALSE ALTITUDE OUTPUTS ..................................……………..42 CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS ……… ………44 GENERAL…………………………………………………………………. 44 CDNU BIT…………………………………………………………………. 45 AUTO-CALIBRATION…………………………………………………… 46 HEIGHT INDICATOR LAG……………………………………………… 47 STANDBY TO TRACK TRANSITION TIMES………………………….. 48 MAXIMUM ALTITUDE RANGE………………………………………... 49 ALTITUDE UPDATE RATE……………………………… ………………50 FALSE ALTITUDE OUTPUTS……………………………………………50 REFERENCES AND BIBLIOGRAPHY ………………………………..……… 51 APPENDICES …………………………………………………….. ………………53 APPENDIX A: DETAILED TEST MATRICES………………………….. 54 APPENDIX B: LPIA DETAILED METHOD OF TEST…………..………62 APPENDIX C: DEFINITION OF DEFICIENCIES………………. ………67 VITA ………………………………………………………………………………. 68 viii LIST OF TABLES TABLE 1: EA-6B LPIA TEST ENVELOPE………………………………… 21 TABLE 2: EA-6B LPIA FLIGHT TEST CONFIGURATIONS…………….. 21 TABLE 3: LPIA RANGE BINS……………………….…………………….. 22 TABLE 4: CBIT STATUS WORD DEFINITIONS…………………………. 31 TABLE A-1: DETAILED LPIA GROUND TEST MATRIX………………….. 54 TABLE A-2: DETAILED LPIA FLIGHT TEST MATRIX……………………. 58 TABLE B-1: PITCH TRANSITION PROFILE DIVE RECOVER RULES…… 63 TABLE B-2: LPIA DT RANGE BINS……………………….………………… 64 TABLE C-1: DEFINITION OF DEFICIENCIES………….…………………… 67 ix LIST OF FIGURES FIGURE 1: THREE VIEW OF EA-6B AIRCRAFT…………………………… 5 FIGURE 2: RADAR ALTITUDE INDICATOR……………………………….. 8 FIGURE 3: ELECTRONIC ATTITUDE DIRECTION INDICATOR………… 12 FIGURE 4: CONTROL DISPLAY NAVIGATION UNIT-900……………..… 15