Virtual Technology Boost for Aviation Maintenance
Written by Peter Buxbaum
MT2 2010 Volume: 15 Issue: 5 (September)
Advanced simulators are often thought of in the context of operational training, the classic example being for aircraft flight. But the same kinds of technologies that bring a robust realism to flight training are now being leveraged to train maintainers of those same aircraft.
Aircraft such as the U.S. Navy’s F/A-18 jets, being the complex platforms that they are, require rich image and computing environments for maintenance training, no less than for flight training.
“The way I look at it, proper maintenance training solutions have to be analyzed against the task we’re trying to train,” said Greg Pryor, program manager for individual training at the Naval Air Warfare Center Training Systems Division (NAWCTSD) in Orlando. “I find the maintenance trainers to be extremely effective for cognitive skill sets and for developing overarching, top-level skills like troubleshooting.”
The best maintenance trainers are those that have analyzed how and where to best utilize the virtual environments they provide, according to Arnold van den Hoeven, director for Canadian Defense at Ngrain. Ngrain developed a series of five trainers for the Canadian Air Force Lockheed P-3 Orion aircraft, including one for air conditioning and pressurization.
“As those systems go through a full cycle, the airplane can’t be used for training or other purposes,” said van den Hoeven. The other Ngrain maintenance trainers for the P-3 are for avionics, engine, corrosion control and the Mark 46 torpedo.
A case for creating a virtual environment presented itself in the case of Mark 46 torpedo maintenance trainer because of the danger involved in handling real torpedoes, and in particular, their toxic fuels.
An F/A-18 simulator, developed by American Systems, replaced traditional school training “where trainees went and worked out on a perfectly good aircraft and effectively broke it,” said Damian Szigeti, the company’s engineering manager and the designer of the F-18 training system. “Now they can work with the aircraft all day long. The students get qualified on what they want to get qualified on and then move on.”
“Hard training systems”—in other words, equipment replicas and other non-virtual types of trainers— can accommodate only a limited number of instructors and students at any given time. Simulation systems are able to scale to the needs of the training program, noted van den Hoeven, thus increasing training throughput.
“One thing we focus on as company is creating an interactive training environment,” he added. “Any good training environment has an interactive component.”
American Systems’ F/A-18 Simulated Avionics Maintenance Trainer was developed and fielded around two years ago. Eight of the systems have been delivered to Naval Air Stations Oceana and Lemoore.
The system displays a two-dimensional virtual cockpit and a three-dimensional virtual aircraft maintenance display on a 61-inch plasma screen. The visual system can be scaled down to a 21-inch desktop screen.
Instructors can manipulate any one of 10,000 virtual wires found in the electrical circuits on the aircraft, creating a troubleshooting exercise of the instructor’s choosing to be tracked by students. Students can walk around the virtual aircraft and open and close compartments on the airplane.
“This is a physics-based model,” said Ali Kalwar, the Orlando-based manager of the simulator program. “That means that the model running behind it can simulate all kinds of actions the student is going to take.”
Achieving accuracy for the F/A-18 simulator required taking over 10,000 photographs to deliver the required imagery. Engineering models of the aircrafts systems and several specialized databases had to be developed in order to make the training experience as realistic as possible.
“The interconnect database simulates what happens when one wire is connected to another,” explained Szigeti. “An interference database controls how and in what sequence parts can be pulled off the aircraft.”
The SAMT utilized technology developed by DiSTI Corporation, a provider of 2-D and 3-D graphical user interface software, to create “3-D interactive real-time reusable simulation objects” which synthesize photographs, 3-D models and behavioral logic. The technology is based on DiSTI’s GL Studio, which the company describes as the world’s “first and only” object oriented rapid virtual prototyping and graphics code production tool.
The GL Studio tool kit was released in 2000 and is used to create virtual cockpit human-machine interfaces. “GL Studio stands apart in its ability to produce interface content that serves the entire life cycle of the product, from prototyping new cockpits and displays to taking those displays and interfaces and embedding and deploying content without having to redevelop it,” said Scott Ariotti, the company’s director of sales and marketing.
For the SAMT program as well as other projects DiSTI is working on, such as the Joint Strike Fighter F-35 Aircraft Systems Maintenance Trainer (ASMT) and the F-18 Super Hornet Integrated Visual Environment Maintenance Trainer (IVEMT), the company used GL Studio for the cockpit environment, and custom designed a tool set that Ariotti described as “GL Studio on steroids” for the general aircraft environment. The latter system has yet to be brought to market as a commercial off-theshelf product, but the company has plans for doing just that.
In the case of the ASMT and the IVEMT projects, DiSTI created virtual environments based on computer-aided design data provided by the aircraft manufacturer. “This went into our software conversion and enhancement process,” Ariotti explained, “to add realistic imagery to the airframe and to provide the interactivity for connecting and disconnecting, opening and closing the components and parts on the airplane.”
Image generation technology has progressed in leaps and bounds and with greater speed in recent years, noted the Navy’s Pryor. “There has been an increased speed of development in the image generation business,” he said. “We are able to push these capabilities down into systems. This gives us the ability to build virtual constructs that enable us to train on these systems with higher fidelity.”
Pryor credited the growth of gaming systems with “giving us a much broader and deeper talent pool of people who can build these kinds of models. That has had a direct impact on the improvement in maintenance trainers.”
Ngrain’s starting point in developing what it calls virtual task trainers, or VTTs, involves an analysis of the training plan used at the relevant aviation maintenance school. “We examine and focus on the training and performance outcomes being targeted by the training system,” said van den Hoeven, “and then analyze where effective use of interactive 3-D models can be used to achieve the and desired results.”
Not every maintenance training challenge is best answered with a 3-D display, said van den Hoeven. “We have found that in many cases, a 3-D visualization is not the most effective way to get the message across,” he explained. “Sometimes we elect to insert 2-D animated schematics to do the job. We do not always employ a 3-D approach.”
The Canadian Air Force has benefited from the deployment of Ngrain’s trainers, said van den Hoeven, by having maintenance personnel train on the aircraft from their home bases. “Before they had to schedule courses and people had to be flown in from the West Coast to the East Coast in order to participate,” he said. “They would usually tack this on to some other activity they had to do.”
An aviation maintenance trainer Ngrain developed for the U. S. Coast Guard HC-144 Ocean Sentry maritime patrol aircraft has allowed for greater training throughput over the hard trainers the Coast Guard deployed in the past. “Students are able to be trained outside the normal physical boundaries of a school,” said van den Hoeven. The HC-144 virtual task trainers developed by Ngrain covered the avionics and hydraulics systems.
American Systems says that the technology it has developed for F/A-18 aviation maintenance training is adaptable to other complex training missions. The company has proposed repurposing its technology for maintenance tasks on unmanned aerial vehicles, the Navy’s DDG-51 class of destroyers, and Marine Corps’ ground vehicles, according to Szigeti.
The Navy is planning a limited number of contract awards for the refreshing of maintenance trainer technologies over the next couple of years. One $800,000 contract, expected to be awarded before the end of this fiscal year, will involve the re-hosting of existing government off-the-shelf software and the development of a new graphical user interface for a system that trains on close in weapon system maintenance.
A second contract, for which a request for proposals is expected during the first quarter of fiscal year 2012, will be a $5 million contract that will refresh computer hosting for eight legacy maintenance training technologies covering power plants, avionics, electrical systems, egress, fuel systems, armaments, flight controls and landing gears. “We are open to open source applications and use them where appropriate,” said Pryor. “We make sure that whatever we do provides the best value to the government.”♦