TG-14A Parameter Investigation (Project HAVE MOTO)

The United States Air Force Test Pilot School (TPS) performs six to eight flight test management projects (TMP) annually. The TMPs cover all aspects of flight test including performance, flying qualities, avionic systems, and human factors. The flight tests are performed for a wide variety of government agencies and commercial sector companies. Test teams are composed of TPS students with a broad base of aviation and research flight experience. Student teams consist of four to six students made up of a 50/50 percent pilot/engineer mix. The test projects address all phases of testing from program introduction, through test plan working groups, technical/safety review boards, and test execution, to final oral and written reports. The test execution occurs over a period of 3 to 4 weeks and generally encompasses 4 to 20 flight test sorties. This paper provides the background of the USAF Test Pilot School program in general and the test management projects in particular. An overview of TPS technical capabilities and resources is provided. Examples of recent TMPs are detailed. These examples include efforts with Air Force research laboratories, Air Force major commands, and Technology Transfer programs using Cooperative Research and Development Agreements between the government and private companies INTRODUCTION The United States Air Force Test Pilot School (TPS) is the premier institute for training test pilots, test navigators, and flight test engineers in the conduct of flight test and evaluation of research, prototype, and production aerospace vehicles, systems, and weapons. The capstone event of the TPS curriculum is the test management program (TMP) in which student teams perform an extensive flight test project in support of a broad base of outside agencies. The TMP provides comprehensive end-to-end training in all phases of test management and execution. These programs provide students with practical hands-on test experience from program introduction to writing the final report and providing oral presentations of test results, conclusions, and recommendations to the customer and Air Force Flight Test Center (AFFTQ leadership and technical personnel. The program presents students the opportunity to apply the technical, management, and leadership concepts taught during the course. Emphasis is placed on understanding customer technical requirements within the constraints of cost and schedule demands. To date, TPS has been exceptionally successful in meeting customer requirements and providing real world training for its students. The purpose of this paper is to highlight our recent programs, and to inform outside agencies of our capabilities to perform low cost, quick-reaction flight test programs. USAF TEST PILOT SCHOOL COURSE OVERVIEW The USAF Test Pilot School provides training in three courses: the Experimental Test Pilot Course, Test Navigator Course, and Flight Test Engineer Course. The courses are integrated to instill cooperation and understanding between test team members which is essential for successful flight test operations. Data group teams plan, fly, evaluate, and report on selected test projects throughout the course. The flying program for the pilots develops the knowledge, flying precision, and powers of observation necessary for successful flight evaluations. The flying program for navigators and engineers leads to an understanding of problems pilots encounter and familiarizes them with airborne test tasks needed to accomplish precise flight test techniques. Navigators and engineers perform extensive evaluations of airborne avionics and weapons systems to determine suitability under operational conditions. The course is divided into four phases: (1) Performance, (2) Flying Qualities, (3) Systems Test, and (4) Test Management The Performance Phase develops the theory and methods of evaluating aircraft takeoff, climb, cruise, descent, turn, acceleration, propulsion, and landing performance. The Flying Qualities Phase examines the stability and control characteristics which influence the ease of safely flying the aircraft during steady and maneuvering flight in execution of the total mission. During this phase, aircraft are tested to determine static and dynamic characteristics, estimate stability parameters, evaluate flight control system effectiveness, and measure engine-out handling quality characteristics. The Systems Test Phase evaluates aircraft avionics and their system integration. The Performance, Flying Qualities, and System Test Phases all have integrated academic and flying programs to maximize student training effectiveness. The Test Management Phase academics are integrated throughout the program with the actual test management project execution occurring during the latter part of the course. USAF TEST PILOT SCHOOL TECHNICAL RESOURCES The curriculum is supported with state-of-the-art instrumented aircraft and contemporary data acquisition and analysis systems. TPS serves as a self-contained Combined Test Force (CTF) providing extensive technical capabilities for complete flight test engineering. TPS instructs basic flight test techniques with four instrumented T-38A aircraft. The T-38A aircraft are instrumented with sensitive cockpit instrumentation (airspeed, altimeter, mach, g, angle of attack, and sideslip gauges) and a programmable data acquisition system. All four aircraft possess onboard data recorders and telemetry

A contradiction lies at the core of handling qualities evaluations: The most complex subsystem of the handling qualities loop is both the least understood and most familiar system. This subsystem is, of course, the human body. A test pilot’s lack of understanding of the mechanisms involved in his cognition and motor control is only exceeded by the confidence he shows in his ability to report on them. Nevertheless, satisfactory handling qualities are vital for safe mission accomplishment so the USAF Test Pilot School (TPS) must endeavor to prepare its graduates to rationally conduct these evaluations. In the last five years, the USAF TPS has undergone a steady transformation in the education of its students for these tasks. This change has stemmed partly from changes in the foundational assumptions of how pilots control, partly from TPS research into objective measurements of pilot inceptor motion, and partly from the recognition that traditional pilot modeling approaches serve only as useful analogies that have little in common with the actual mechanisms of human cognition and motor control. This paper will review the history of handling qualities evaluations at the USAF TPS and describe how shifts in the foundations of the School’s understanding of pilot control have encouraged significant adjustments to the aircraft handling qualities curriculum. These adjustments are helping students better understand how their minds and bodies work and are helping them learn how to create and execute flight test techniques that more efficiently and accurately predict aircraft capability.

: This report presents the results of Project Have VEST, a limited evaluation of a back up velocity estimate following air data system failure. This test program demonstrated the potential of the VEST algorithm to provide an airspeed estimate using aircraft last known state and flight control computer accelerations and rates. The USAF Test Pilot School (TPS), Class 07A, conducted six flight tests totaling 11.3 hours at Edwards AFB, California, from 9 to 21 Sep 2007. All test objectives were met.

The 48-week USAF Test Pilot School (TPS) curriculum in performance, flying qualities, systems, and test management culminates in a real -world flight test program under the mentorship of TPS staff. Two Test Management Projects (TMPs) are presented as examples of these student-led flight test programs. Project ACTIVE FIN examined the effectiveness of closed loop digital control of piezoelectric actuators in alleviating buffet induced vibrations on an F-16 Block 15 ventral fin caused by airstream disturbances from the wake of a Low Altitude Navigation and Tracking Infrared for Night (LANTIRN) pod and the landing gear. Project HAVE KNOTS determined the data consistency of the cloverleaf flight test technique, and variations, for pitot-static system calibration.

: This report presents the results of Project SELF SERVE, Limited Evaluation of Autonomous Aerial Refueling Algorithm. The overall test objective was to gather flight test data of the Automated Aerial Refueling algorithm for the Air Force Research Laboratory. The USAF Test Pilot School, Class 03B, conducted 4 flight test sorties totaling 6.5 hours at Edwards AFB, California, from 3 May to 4 May 04. All test objectives were met.

: This technical report presents the results of the arc segment attitude reference (ASAR) head-up display (HUD) symbology as a primary flight reference test and evaluation. Testing was requested by the Air Force Research Laboratory, Human Effectiveness Directorate, Wright-Patterson AFB, Ohio. The responsible test organization was the 412th Test Wing, Edwards AFB, California. The test execution organization was the ASAR HUD test team from the USAF Test Pilot School located at Edwards AFB. Testing was performed on the USAF NF-16D Variable-Stability In-Flight Simulator Test Aircraft serial number 86-0048, from 7 to 23 July 2004 and was comprised of 5 ground simulation familiarization and test sessions totaling 12.0 ground test hours, 2 calibration flights and 15 test sorties totaling 23.8 flight test hours. The overall test objective was to determine if the use of the ASAR in the MIL-STD- 1787C HUD symbology as the principal attitude reference, in place of the climb-dive ladder, improved pilot performance during unusual attitude recoveries, vertical banked S-turn (S-B) and vertical dive S-turn (S-D) maneuvers, and precision ILS approaches. The vertical S-B maneuver was a continuous series of rate climbs and descents flown on an initial constant heading. The vertical S-D maneuver was similar except that the direction of turn was reversed simultaneously with each change of vertical direction. The overall test objective was met.

The T-38A is the primary training aircraft at the USAF Test Pilot School. The aircraft used was fully instrumented for all aerodynamic flight parameters including angular rates, accelerations, and control surface positions. Flight test data were obtained over a series of sub-sonic and supersonic test points in the clean aircraft configuration. The flight test data were reduced using the System Identification Programs for AirCraft (SIDPAC) toolbox for MATLAB resulting in an aerodynamic model of the T-38A. The investigation identified several considerations when conducting a shortterm, limited scope model identification test. The lessons learned from this application may be applied to further studies of aircraft dynamics.

The US Air Force (USAF) Flight Test Center has made recent advancements in its system identification capabilities. The most recent project from the USAF Test Pilot School (TPS) was to implement a near real-time parameter identification curriculum sortie. This sortie development entailed automatic parsing of input doublets and then analyzing these doublets using equation error. The Global Vigilance Combined Test Force would like to take the next step toward more rapid parameter identification, specifically by extending beyond the previous equation error techniques and advancing towards trajectory reconstruction, i.e. data compatibility and output error. The paper herein demonstrates how to solve for aerodynamic stability and control derivatives via dynamic optimization using pseudospectral methods. Future research may include time delay which can be added as another optimization parameter, thus resolving issues with heavily filtered instrumentation data. The inherent implicit integration within the pseudospectral method has already shown improved stability over traditional explicit integration within shooting methods (1) . Also, by optimizing the solution using a smaller finite number of nodes, the convergence time may drastically improve over explicit or sequential integration. Lastly, by using segmented adaptive node distribution, vice a single segment, a more accurate solution may be obtained using the same number of nodes. The work herein introduces a new method for system identification algorithms. This is intended to be an extension, or improvement, upon the existing accomplishments within the System Identification Programs for Aircraft (SIDPAC) software documented in Aircraft System Identification: Theory and Practice by V. Klein and E.A. Morelli. The pseudospectral method and the General Pseudospectral Optimal Control Software (GPOPS) to solve dynamic optimization problems are already established. This paper extends these established techniques towards this new application. These results are modeled after textbook examples for output error. This technique is motivated by the desire to develop a practical real time parameter estimation capability.

<div class="htmlview paragraph">A three-phase flight test program to evaluate the A-10 Single Seat Night Attack (SSNA) aircraft was conducted at the Air Force Flight Test Center (AFFTC), Edwards AFB, CA. An important objective of the SSNA testing was to assess, and where possible, measure pilot workload. The techniques utilized during the test program to quantify workload were: An objective measurement of task performance, control activity, and physiological status data, and the Subjective Workload Assessment Technique (SWAT). The use of objective techniques represented the first application in a flight test environment and an initial attempt to validate their use as work-load metrics. Both objective and subjective methods were of significant value, but both techniques had limitations and shortfalls. Lessons learned affecting the application of the techniques to on-going and future flight test programs are described.</div>

A flight test was performed with the NASA Lewis Research Center's DH-6 icing research aircraft. The purpose was to employ a flight test procedure and data analysis method, to determine the accuracy with which the effects of ice on aircraft stability and control could be measured. For simplicity, flight testing was restricted to the short period longitudinal mode. Two flights were flown in a clean (baseline) configuration, and two flights were flown with simulated horizontal tail ice. Forty-five repeat doublet maneuvers were performed in each of four test configurations, at a given trim speed, to determine the ensemble variation of the estimated stability and control derivatives. Additional maneuvers were also performed in each configuration, to determine the variation in the longitudinal derivative estimates over a wide range of trim speeds. Stability and control derivatives were estimated by a Modified Stepwise Regression (MSR) technique. A measure of the confidence in the derivative estimates was obtained by comparing the standard error for the ensemble of repeat maneuvers, to the average of the estimated standard errors predicted by the MSR program. A multiplicative relationship was determined between the ensemble standard error, and the averaged program standard errors. In addition, a 95 percent confidence interval analysis was performed for the elevator effectiveness estimates, C sub m sub delta e. This analysis identified the speed range where changes in C sub m sub delta e could be attributed to icing effects. The magnitude of icing effects on the derivative estimates were strongly dependent on flight speed and aircraft wing flap configuration. With wing flaps up, the estimated derivatives were degraded most at lower speeds corresponding to that configuration. With wing flaps extended to 10 degrees, the estimated derivatives were degraded most at the higher corresponding speeds. The effects of icing on the changes in longitudinal stability and control derivatives were adequately determined by the flight test procedure and the MSR analysis method discussed herein.

: The HAAFT program was conducted to obtain high altitude radar altimeter data that could be used in a feasibility assessment of High Altitude TERCOM (HATCOM). The HAAFT program involved collecting altimeter data over seven scenes with terrain altitude standard deviations ranging from 25 to 320 feet located in the vicinity of Edward AFB and Point Mugu, California. Two pulse and one FM/CW altimeters were operated simultaneously at nominal altitudes of 5, 20, 30, 45, and 65 kft, AGL. The aircraft three-dimensional position was measured and provided by the AN/FPS-16 radar sets at Edwards AFB and Pt. Mugu. The tracking data were later merged with the data recorded in the aircraft and stored on computer tapes. An inertial navigator was included in the flight test equipment to provide aircraft attitude, velocity, and position data. In addition to the normal altitude measurement data provided by the altimeters, the pulse return waveform for the pulse altimeters and the prediscriminator waveform for the FM/CW altimeter were processed to be recorded on television video cassette recorders.

: The Structures Flight Test Handbook was written principally as a training aid for new engineers assigned to the Air Force Flight Test Center (AFFTC), Edwards AFB, California. Experienced structural flight test engineers may find the hand hook useful as a reference and resource guide only.

The 11F-5E single cockpit tactical reconnaissance aircr;i.ft was designed in 1981 to carry a variety of low, medium, and high altitude sensor configurations mounted internally on interchangeable pallets. Recently,. Northrop has incorporated CAI's high resolution KS-147A LOROP (Long Range Oblique Photographic) camera into the aircraft to provide long-range standoff capability., Key features of the KS-147A camera include a 66-inch focal length, f/5.6 lens; closed loop autofocus; two axis, gyro-stabilized scan head, and a passive isolation mount to reduce aircraft motion inputs; a self-contained thermal system to stabilize temperature-sensitive optics; and all electronics required to control camera-to-aircraft interface functions. Key aircraft changes to accommodate the camera include a new three-sided camera bay lower door with side oblique windows, a new stronger camera-mounting pallet, a new cockpit forward control panel, new temperature control system ducts, new wire harnesses, and new side oblique sights., This paper addresses laboratory and flight test activities conducted on the KS-147A camera and the RF-5E aircraft. Included are development and qualification testing of the camera, preflight thermal conditioning. tests of the camera in the aircraft, and finally, a detailed discussion of the flight testing at Edwards AFB, and verification of the in-flight photo resolution requirement of 70 line pairs per mm.

: The flight testing of propulsion systems has always centered on engine response and operability. The flight testing and evaluation process can be data intensive due to the sophistication of the hardware and software and the fact that response and operability needs to be verified throughout the entire aircraft flight envelope. This is true whether the item under test is a new engine or a modification of an existing engine. The analysis of engine operability has traditionally been a manually intensive process. Determination of when a critical event occurred (e.g., combustor light-off or engine stability) can vary from engineer to engineer. The variance can be attributed to the fact that critical events are not always clear and at times depend on a judgment call by the engineer doing the analysis. This paper will present the automated analysis of engine airstarts and throttle transients. This analysis was performed using a MATLAB-based analysis and plotting software tool developed at the Air Force Fight Test Center (AFFTC), Edwards AFB, California. The program was called the Airstart and Transient Analysis Program (AirTrans AP).

Three different types of maneuvers were designed to separately quantify pitch rate and angle of attack rate contributions to the nondimensional aerodynamic pitching moment coefficient. These maneuvers combined pilot inputs and automatic multisine excitations, and were own with the subscale T-2 and Bat-4 airplanes using the NASA AirSTAR flight test facility. Stability and control derivatives, in particular C(sub mq) and C(sub m alpha(.)) were accurately estimated from the flight test data. These maneuvers can be performed with many types of aircraft, and the results can be used to increase simulation prediction fidelity and facilitate more accurate comparisons with wind tunnel experiments or numerical investigations.