The Systems Research Aircraft

The Systems Research Aircraft (SRA) is a dual-purpose facility benefitting commercial and military developments. A primary objective is to identify and flight-test high leverage technologies beneficial to subsonic, supersonic, hypersonic, or space applications. The SRA flight test facility will enable government and industry to focus the integration, ground test, and flight validation of breakthrough technologies. The intent of flight testing new technologies is to eliminate perceived and real technical barriers. It is anticipated that the development and flight test of advanced vehicles will use technologies that can be flight validated with the SRA.

Flight critical and non-flight critical experiments can be targeted for the SRA Facility. Examples of experiments that would be considered flight critical include systems such as electric actuation for critical surfaces and closed-loop, fly-by-light (FBL) options. Demonstrating new system concepts in flight will greatly promote the transition of research and development technology from widespread, highly specialized ground-based laboratories to future cost-effective flight research and production applications. The systems testbed approach used by the SRA Facility will lower development cost, decrease the time needed to develop new technologies, and focus research efforts.

Flight test goals within the next one to two years include validating concepts in advanced actuators, fiber-optic sensors, flush airdata systems, sensor data fusion techniques, inertial guidance algorithms, and advanced, open systems computer architectures. Longer term goals include the flight test of a FBL control system and an integrated more-electric aircraft power management and distribution system with power-by-wire actuators for critical surfaces. Several candidate technological areas are being considered by NASA Dryden Flight Research Center (DFRC) for SRA ground or flight experiments. They include active flutter suppression, onboard envelope expansion techniques, pilot associate systems, advanced displays, massive parallel processing architectures, vehicle management techniques, automated vehicle checkout techniques, and advanced vehicle system interfaces.

The SRA facility will take advantage of several DFRC F-18 related resources which increase the capabilities of ground test systems, flight test facilities, and analysis applications. The SRA facility will provide system researchers with a cost-effective approach to flight test. This information will describe the SRA flight research facility, and outline the first series of experiments to be flight tested. The aircraft has a variable camber wing with hinged leading- and trailing-edge flaps. The leading-edge and trailing-edge flaps and ailerons are hydraulically actuated. Leading-edge extensions run from the wing roots to just forward of the cockpit. Twin vertical stabilizers are at a 20° angle from vertical. The twin rudders and differential stabilators are also hydraulically actuated. The speed brake is mounted on the top side of the aft fuselage between the vertical stabilizers. The cockpit is pressurized and enclosed by an electrically operated clam shell canopy. Aircraft equipment bays to house experiments include left and right fuselage equipment bays, the radar bay, the rear cockpit and the nose cone area.

The SRA Systems

Flight Controls and Avionics

Redundant left and right surfaces offer advantages for experiments relating to comparison studies of new versus conventional applications. Being able to apply experiments to surfaces considered to be non-critical in most areas of the envelope such as the ailerons offers risk reduction advantages.

Data Acquisition System

The SRA is being equipped with a data acquisition system capable of measuring, recording, and telemetering over 8000 parameters. The current configuration is for 713 parameters. Output of the data acquisition system is recorded onboard and telemetered to a ground receiving station for real-time display and evaluation.

Ground Test Facilities

Most major ground tests on the SRA Facility will be accomplished in DFRC's Integrated Test Facility (ITF). The ITF ground test systems include real-time, nonlinear, aerodynamic simulation systems, real-time data recording systems, and a suite of computer-aided systems testing (CAST) software tools. The CAST tools provide real-time data capture, monitoring, and analysis. The CAST tools include closed-loop, automated testing techniques. The ITF systems allow for batch simulations, real-time software simulations, flight-hardware, iron bird, and aircraft-in-the-loop ground test configurations for the SRA Facility.

Airborne Research Test System (ARTS)

The ARTS is an advanced, open systems, computer architecture developed as an onboard experiment support capability unique to the SRA Facility. The primary objective of the ARTS is to provide researchers with the ability to rapidly transition desktop applications to flight test. This is done by providing research application software with easy access to real-time, engineering-unit (EU) data. This will minimize the need for research engineers to develop custom program support hardware. The ARTS consists of two major subsystems: the input/output processor (IOP) and the application processor (AP). The IOP is a single-board VME computer supported by the a real-time operating system. The AP is a single-board VME computer supported by the UNIX operating system.

Curator: Roy J. Davis(davisrj@arts.dfrc.nasa.gov)
Modified:February 1, 1995 by yvonne_kellogg@qmgate.dfrc.nasa.gov