Inside the Cabin Bulkheads
Written by Marty Kauchak
MORE AFFORDABLE, HIGHER-FIDELITY SUBSYSTEMS ARE INSTALLED IN FLIGHT SIMULATOR CABINS.
The government/industry team is providing training audiences with higher-fidelity representations of actual fixed and rotary wing cockpits. More affordable and higherfidelity radar simulations, control loading systems and other components allow prospective and veteran aviators to train as they will operate—inside ground-based training systems.
SELECT SUBSYSTEMS
Wittenstein aerospace and simulation delivers control loading systems and other materiel for installation in training devices in the United States and overseas.
One significant U.S. program of record supports Link Simulation and Training’s contract for the Army’s Aviation Combined Arms Tactical Trainer (AVCATT) program. Under this contract Wittenstein is providing the prime contractor with control loading systems, sticks and grips. Final materiel deliveries to Link under this contract are forecast for later this year.
Wittenstein uses commercial off-the-shelf technology and best-of-breed products to deliver an industrial-type product, based on industrial-type gearboxes and motors, for AVCATT. The company has refined its components over the life of the contract through internal R&D efforts—with inputs from its government and industry customer, Scott Metcalfe, systems engineering manager, told MT2.
“The control loading has to have a ‘smooth feel,’ very close to an operational aircraft, the real thing, in terms of smoothness. So we have worked very hard in terms of developing our actuator systems to reduce the cogging of the motor and the feel of the gear teeth imparted by the gear box,” Metcalfe said. One of many improvements to the company’s control loading products includes replacing its gear box’s straight-cut gear with a helical gear.
The upgraded components are available for delivery for AVCATT and any follow-on international sales of this training system. Wittenstein’s products are also in use in Boeing’s F-15E distributed mission trainers for the Air Force. The company provides a modular control loading system that supports requirements for procedural tasks and mission training.
Representative international training systems supported by Wittenstein include those for the Canadian F-18 [CF-18].
Blue Ridge Simulation (BRS) delivers its radar simulators for an expanding list of U.S. and overseas training devices.
Tom Allen, company president, BRS, noted the ever-expanding capabilities of PC technology allow the company to virtually replicate the imagery produced by even the most advanced radars in real time. “The days of using high-end mainframe computers and array processors are long gone. For example, our simulated synthetic aperture radar [SAR] and inverse synthetic aperture radar [ISAR] models can reproduce these high-resolution imaging modes even faster than the real radars can produce them.”
Many of the company’s radar simulation system (RSS) units are configured to stimulate actual shipboard or aircraft equipment, capable of outputting simulated radar data at the same rate, pulse by pulse, as the actual radar equipment. “The real radars are limited by the speed of light, but our systems are not. Our SH-60B AN/APS-124 RSS is an example of this. The RSS transmits radar and IFF data streams to actual data link equipment for transmission to naval shipboard equipment, which processes and displays the data to the operator just as the actual SH-60B helicopter transmits data to a Navy vessel,” Allen pointed out.
BRS recently supplied eight radar simulators for the Navy’s E-2C Deployable Readiness Trainer, providing an advanced simulation of the E-2C AN/APS-145 radar. Allen noted that “each radar simulation system drives three radar consoles from a single PC, housed together with the other trainer components in a single portable rack. It provides a compact, effective E-2C aircrew trainer that is easily transported and deployed throughout the world as necessary.”
In January, BRS delivered the first of seven AN/APQ-164 RSS units for the Air Force’s suite of B-1B trainers. As part of a major upgrade to the B-1B trainers, these RSS units will replace legacy systems, providing improved fidelity, including a high-resolution SAR imaging capability.
BRS has also provided a total of 13 RSS units for the Navy’s new fleet of MH-60R trainers, and continues to support the development of additional trainers. “These devices simulate the newly developed AN/ APS-147 multi-mode radar, including inverse synthetic aperture radar for long-range surface vessel identification, and high-capacity target tracking capability,” Allen pointed out.
BRS recently supplied six RSS units for incorporation into AAI’s desktop T25 Simulator for Electronic Combat Training desktop trainers. This RSS simulates all modes and functions of the AN/ APN-242 navigation radar for combat systems officer (CSO) training at Randolph Air Force Base. The T25 combines this radar simulator with simulated electronic warfare (EW) equipment, reflecting the Air Force’s combination of separate navigator and EW officer positions into a combined CSO role.
For its part, Polhemus has delivered head tracking devices for a number of training systems, including AH-64D Apache Longbow crew trainers and simulators for the F/A-18 and F-16. The company’s head trackers also support the training aspects for the fielded Joint Helmet Mounted Cueing System.
Head trackers are used in DoD flight simulators to accurately and quickly determine the pilot or crewmember’s line of sight. “This is paramount when training to use helmet-mounted cueing systems since high-speed tracking allows the image generator to draw the correct symbology relative to the pilot’s point of regard in nearly real time. This is particularly important when accurately slewing a targeting pod or drawing the visor display reference symbology is a priority,” Skip Rodgers, program manager, military and government systems, Polhemus, explained for MT2. Low tracker latency and point-of-regard accuracy improve overall simulator fidelity and training effectiveness. “With better than two-milliradian installed accuracy and four-millisecond latency, Polhemus head tracker performance is outstanding,” Rodgers said.
The company’s portfolio includes two products of interest. Fastrak is a multi-channel magnetic head tracking device designed to be extremely accurate in both head orientation and position tracking while simultaneously being extremely fast with its data output (low latency). “This platform has been the standard in high-fidelity simulators for nearly 15 years,” Rodgers remarked.
Scout is the latest generation head tracker from Polhemus. “It stands to revolutionize the simulator cockpit industry by merging Fastrak accuracy and increased tracking speed into a lightweight and never-before-seen self-contained micro tracker. The entire sensor and tracker can be mounted on a helmet, headphones or other preferred headwear for a truly simplified integration,” Rodgers added.
Fidelity is also imparted in ways beyond what electrons can provide.
Fain Models Ltd. operates from a 40,000-square foot plant located in Bedford, Texas, and supplies flight simulation hardware, prototype models and machining services to a variety of markets. “One area of expertise is Fain’s design and manufacture of replica aircraft ejection seats,” Glenn Freeman, company spokesperson said. The foundation of Fain’s design capabilities is an extraordinary library of details about the world’s ejection seat systems. “The availability and access to high-definition details is afforded by the professional relationship and agreements developed with the world’s ejection seat manufacturers,” Freeman added.
Fain Models ensures every design has the same look, function and feel as the actual aircraft. “From low-fidelity, nonfunctional hardware to high-fidelity, full functioning replicas, each seat features true-to-original equipment manufacturer product colors, decals and training system functionality designed according to each customer’s requirements,” Freeman pointed out.
Representative of the replica ejection seats Fain has manufactured, by model, are: ACES II F-16, F-15, F-18, SJU-5/6A, SJU-9/10A, Mk.10, Mk.16, T-45 and F-35.
In addition to ejection seats, the following are a few of the other flight simulation products Fain manufactures: throttle quadrants, flight controls, ejection sequencers, access doors, crew doors, parttask trainers, heat exchangers, a variety of duct and tube assemblies, hydraulic reservoir assembly and landing gear strut assembly inertia reels.
FIDELITY AND AFFORDABILITY
At the end of the day, a flight simulator environment must supply a high-fidelity event for the training audience’s different requirements. “When you talk to the pilots they want the feel, not necessarily the actual forces required, but the robustness of the equipment has to be the right level,” Metcalfe said.
Indeed, discussions among Metcalfe and service customers at the 2008 I/ITSEC revealed the increasing occurrence of negative learning experiences, which are created by low-end gaming technology controls.
The rate of technology innovation is contributing to higher-fidelity representations becoming more affordable.
In one instance, affordability is a diminishing concern for most radar simulation applications, since low-cost PC-based hardware has eliminated hardware cost as a driving factor for radar simulation. BRS’s Allen observed that the cost tradeoffs for fidelity basically amount to two things: non-recurring software engineering and high-resolution data for special imaging modes like certain SAR applications. “We address these issues by minimizing redundant effort across different programs,” he said. “As a specialized radar simulation company for the past 15 years, BRS is well suited to maximize software reuse from project to project, thereby minimizing cost. Our BRS radar library represents a very advanced collection of physics-based radar models, which constitutes the core of each RSS application.” Most radars can be accurately represented with relatively minor tailoring, using a software “wrapper” of application-specific code. Optional software plug-ins can be incorporated for special purposes like SAR, ISAR and image generator terrain server support. “Thus we are able to offer very advanced radar simulation capability for a wide variety of simulator projects with minimal nonrecurring cost,” Allen remarked.
NEAR-TERM DEVELOPMENTS
A number of new products and upgrades will be fielded through the remainder of this year.
An internal Wittenstein R&D effort is developing a lower-cost, but robust, control loading system. “This will try to bridge that gap between the joystick on gaming equipment and our systems that are Level-D capable. It will be something in between—with the robustness and feel fidelity but not necessarily the functionality provided by the current system,” Metcalfe added.
Polhemus plans to add high-performance-extended Kalman-based H2 predictive filtering to many of its tracker lines. “This will aid integrators in meeting the rigorous demands for overall low latency of the visual system,” Rodgers remarked.
The company is also demonstrating the utility of its Scout system in other live and virtual environments—as it continues to streamline the integration process of the Scout head tracker into both real vehicle and simulator platforms. “The days of complex environment-based calibration are behind us; without question, the Scout platform provides the industry with the edge in tracking performance and value,” Rodgers concluded.
BRS will provide embedded radar simulators for the Navy’s T-45 Virtual Mission Training System (VMTS). Boeing, as prime contractor, selected Elbit Systems as chief supplier of the VMTS, which will integrate realistic radar training into the actual T-45 aircraft. BRS, in turn, will supply its RSS as a key component of the VMTS under a subcontract from Elbit. ♦