This unique book serves as both text and practical reference for all personnel involved in avionics and weapons system evaluation and testing, in the air and on the ground. Whether you are training pilots and personnel or actually planning to test systems, this book will provide you with the fundamentals and practical information you need to get the job done. The book is a compilation of experiences and methods from over 25 years in the business and interaction with Test Pilots and Test Engineers over the last 15 years as an Instructor/Director at the National Test Pilot School in Mojave, California. The book was also reviewed by a dozen voluntary experts from the military and industry to ensure all critical components are covered properly. Their comments and suggestions were integrated into the text toward the goal of creating this invaluable textbook and companion to the fighter or heavy aircraft test team, no matter their geographical location. Lessons learned, good and bad, are addressed in each chapter so readers can avoid the pitfalls common to test and evaluation of these systems. Exercises at the end of each chapter provide instructors with the ability to reinforce critical concepts and all the war stories in the book are true.
Inspec keywords: aerospace testing; certification; electronic warfare; data reduction; infrared detectors; avionics; weapons; electro-optical devices; system buses; radar; navigation; data analysis; distance measurement
Other keywords: electronc warfare; radar; infrared systems; time information; electro-optical systems; communications flight test; space information; data analysis; data reduction; MIL-STD-1553; digital data busses; ranging; weapons integration; navigation systems; aircraft avionics; position information; radio detection; avionics civil certifications; evaluation; weapons systems
Subjects: General electrical engineering topics; Aircraft electronics; Radio links and equipment; Electronic warfare; Weapons; Computer communications; Aerospace testing and simulation; Electro-optical devices; Spatial variables measurement; Radionavigation and direction finding; Photodetectors; Radar equipment, systems and applications
There is little written on the specific subject of avionics and weapons systems testing, but there are articles and tutorials available that address the general subject of testing and experiments which are included in this text. Understanding customer requirements, test team goals and responsibilities, and the nature of the test program allows us to formulate, or estimate, the program. It is important to realize that undertaking an estimate without first determining these aspects is a recipe for failure. Each estimate should follow a tried and true methodology: determine the type of program and the required outcome, determine the assets required to perform the task in the time allotted, and estimate the task. Discussed are the factors that affect the type of program and addresses the assets required for the time allowed.
All testing of avionics and weapons systems requires that the tester prove the performance of the system under test by measuring its performance against some known quantity. This known quantity falls under the heading 'truth data,' or time, space, position information, affectionately known as TSPI. The concept is slightly different from the testing accomplished on the vehicle side of the house. In loads testing for example, the tester relies on instrumented parameters to determine the 'true' bending and torsion on a member. The accuracy of the result depends entirely on the accuracy of the instrumentation system. The tester in this case is measuring the truth and comparing this answer to the predicted results. In avionics and weapons system testing, we still collect instrumented parameters such as latitude, longitude, and altitude, but we compare them to an outside reference, a truth. This truth is generated by calibrated reference systems such as cinetheodolites or an on-board global positioning system (GPS). It is important that our truth system be accurate enough to measure the expected performance of the system under test. Unfortunately, all too often testers use whatever TSPI system is available without considering the impact on the results of the test. In some cases, highly accurate avionics systems are being measured by TSPI systems that are not as accurate as the system under test! This chapter discusses what systems are available, how the results can be improved upon, and defines a common-sense approach for identifying required test assets.
The transfer of data on today's aircraft is accomplished by data bus architecture. Data acquisition is the art of extracting data from these busses and converting them to some meaningful units that can then be analyzed. This text is designed to give a working knowledge of data bus technology that allows every engineer to speak intelligently to software design engineers and instrumentation personnel. It also helps every engineer appreciate those personnel who provide data . Data acquisition today is a little more complicated than calibrating voltages for strip chart pens.
The flight testing of communications systems is avionics flight testing in its most basic form, but it does illustrate many of the common factors seen in the more complex systems. The testing of communication systems occurs more often than one would expect. Radios are often upgraded, which requires a flight test program, but these upgrades may be many years apart. What occurs on a more frequent basis is the relocation of antennas or the installation of stores or other obstructions that may affect communications. Some flight testing may be required to ensure that no degradation of communications due to these modifications has occurred. Radios, because they transmit as well as receive radio frequency (RF) energy, are also key players in electromagnetic interference/electromagnetic compatibility (EMI/EMC) testing. This testing is addressed later in this chapter.
Navigational systems is a rather large subject area. This chapter covers basic radio aids to navigation such as very-high-frequency (VHF) omnidirectional range (VOR), tactical air navigation (TACAN), nondirectional beacon (NDB), and distance measuring equipment (DME). It also covers self-contained navigational systems such as inertial navigation systems (INSs), Doppler navigation systems (DNSs), and the global positioning system (GPS). Additional topics of interrogate friend or foe (IFF), mode S, and data link are also addressed. This chapter also covers a brief discussion on long-range navigation (LORAN).
The part 23/25 in the title of this section refers to Federal Aviation Administration (FAA) and European Aviation Safety Administration (EASA) (formerly Joint Aviation Administration) definitions of aircraft types. Part 23 aircraft are defined as normal, utility, acrobatic, and commuter category airplanes; part 25 defines transport category airplanes. The discussions in this section are applicable to part 27 (utility helicopters) and part 29 (transport helicopters) as well as military installations. The systems in this section have, for the most part, been developed for the general and commercial aviation market, or mandated for use by the state authorities. The emphasis is on compliance with the applicable certification requirements and sometimes spent on the civil certification process, its history, and a review of the types of documents that you will need to reference. The discussion continues with hardware, software, and safety considerations and the requirements for each. Controls and displays and human factors, which are considerations for all test plans,were discussed in detail and documents to assist in the test planning process will be identified. The systems which are covered include weather radar, global positioning system (GPS) civil certifications, reduced vertical separation minima (RVSM), terrain awareness warning systems (TAWSs), traffic alert and collision avoidance systems (TCASs), flight management systems (FMSs), landing systems, autopilots, and integrated navigation systems.
This chapter deals with the flight testing of electro-optical (EO) systems (e.g., day television [TV], image intensification [I2] systems, etc.) and infrared (IR) systems (e.g., forward-looking infrared [FLIR], IR line scanners, etc.). There have been vast improvements in both of these types of systems as a result of miniaturization, production techniques, and processing technology since their introduction to the military world in the 1960s. As accuracies in detection and identification improve, the method of testing these systems becomes more exact. As with radar testing, the evaluator must be cognizant of the target environment and how changes in this environment alter the results of testing.
Radar evaluation is perhaps one of the most exhaustive, complex, and challenging types of testing that the flight test engineer will encounter. As with all other avionics and weapons systems, it is imperative that the evaluator possess a basic knowledge of radar and an indepth knowledge of the system under test. The purpose of this section is not to repeat what is contained in the aforementioned references. Radar theory is covered only to make the test procedures understandable. This section will review radar fundamentals, identify radar modes of operation, examine the methods of test for these modes, and address any special test considerations.
For the most part, technical or operational discussions of electronic warfare (EW) and electronic countermeasures (ECM) are classified and are restricted to a 'need to know' basis. This chapter will not discuss classified material, but will try to guide the evaluator through a basic knowledge of EW systems and provide a generic series of tests that can be tailored to a specific system.
In this chapter we will discuss the system aspects of weapons integration. The chapter is not concerned with loads, flutter, captive carry, or station clearance issues, although they will be touched upon during the discussions. As usual, there are some references that are available to the evaluator, and these will be quoted where necessary.
As the name in the title implies, this chapter is a recap of the text put into the context of a real integration program. It attempts to take the reader from 'womb to tomb' on the test program, attempting to touch on all of the variables the evaluator confronts. For this exercise, the author integrates a high-speed antiradiation missile (HARM) into the F-14D.
