ATM Modernization, Military

ATC Simulation: USAF Takes a Giant Step

By David Jensen | August 1, 2002
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The Training Systems Product Group at the Aeronautical Systems Center, Wright-Patterson AFB, Ohio, in early April awarded an about $72-million order for approximately 94 control tower simulators. The contract for the Tower Simulation System (TSS) program contains annual production options through 2007 and covers up to 10 years of warranty and after-sales support. It also includes annual options for contractor logistic support through 2011 and for a technical refurbishment study in 2004, which could result in simulator upgrades from 2005 to 2007, if funding is available.

The TSS contract is a plum for Adacel Systems Inc., a North American-based subsidiary of the software engineering firm, Adacel Technologies Ltd., headquartered in Melbourne, Australia. One of five Adacel divisions, Adacel Systems Inc. produces ATC simulators at its facilities in Montreal and Grand Prairie, Texas. The company won the TSS contract over Raytheon, AAI Corp. and Evans and Sutherland, partnered with Micronav.

Adacel can produce both ATC simulation hardware and software and is doing so for the Canadian Forces, which ordered a 360-degree simulator in March 2002. For the TSS contract, however, Adacel decided to produce the simulation software only and subcontract production of the commercial off-the-shelf (COTS) simulator hardware to TRW, according to Michael Asch, Adacel’s vice president of sales and marketing. TRW also will provide TSS system integration and after-sales support.

Adacel is to deliver four TSS simulators this year to the Eglin (Fla.), Barksdale (La.) Little Rock (Ark.) and Grand Forks (N.D.) bases. Three of the simulators will be used for system evaluation, during which the Air Force can request changes. "But when the third system is accepted," says Asch, "the design will be frozen, and the remaining 91 simulators will be identical to that version." The first system is scheduled to go to Eglin in October.

In 2003, Adacel plans to deliver 20 to 25 simulators, says Asch. Air Force Flight Standards, in concert with the major commands, will prioritize the schedule in which the bases will receive the TSS.

Giant Step

The TSS program represents a giant step for the Air Force. Currently, the service has just 10 Tower Pro 200 simulators at Keesler AFB, Miss., to provide basic controller training to about 650 persons a year, according to an Air Force official. But it has no tower simulators in the field, so when the newly trained controllers are assigned to their bases, they must continue their training and become familiar with the local rules and airspace environments using mockup boards and while on the job.

TSS, therefore, "is not really a replacement program," according to Lt. Col. Justin Seiferth, division chief of the Air Force’s Navigation and Landing Systems Division. "It’s a new capability, placing unit-level training devices at ATC facilities on Air Force, Air Force Reserve and Air National Guard bases worldwide.

"The primary reason for placing tower simulators at the unit level is to dramatically reduce the time required to upgrade trainees from the apprentice level to the journeyman skill level and to assist in certifying them for their position," says Seiferth. The TSS simulators’ primary mission is to train controllers, he adds, but they "will also provide referesher and continuation training and will eventually be able to train for deployments and reassignments.

"In the future, the TSS could be used to model new tower locations and similar tasks," he says. The Adacel simulator, incidentally, is dual-option, which means the Air Force can use it as a radar control simulator, as well as a tower control simulator.

Seiferth says the TSS simulator was not acquired to help "increase the number of controllers." The goal of TSS is "to increase the number of ‘qualified’ controllers by dramatically reducing the time it takes to qualify them." He adds that TSS "should reduce the time needed by about 50 percent."

The Air Force’s authorized strength is 3,200 controllers. "Currently, we have about 2,000 qualified controllers," says Seiferth.

Although TSS simulators are to be fielded at bases throughout the world, 10 eventually will replace the 1997-vintage Tower Pro 200 simulators at Keesler. The existing tower simulators were produced by Wesson International, a Texas company that is now part of Adacel. (Adacel Systems was formed in August 2001 as a result of the amalgamation of Wesson and Montreal-based ATS Aerospace.) Approximately 10 simulators will be deployed to air bases outside the United States.

Tall Hurdles

Why has the Air Force not had tower simulators in the field? Air Force officials admit that a need for tower simulation always existed, but until now, the applicable technology wasn’t available. Indeed, the Air Force drew up challenging requirements for this largely COTS program.

One requirement is the simulator’s overall size, or footprint. The TSS system must provide a screen that has a 180-degree horizontal and 30-degree vertical field of view (FoV), yet fit in a room no larger than 15 by 18 by 8 feet (4.6 by 5.5 by 2.4 meters). Air Force officials explain that many of its towers are in older facilities that do not have rooms spacious enough to accommodate a large simulator footprint. "Floor space at all facilities, particularly control towers, RAPCONS [radar approach control centers] and other air traffic control facilities is extremely limited," adds Seiferth.

Adacel is delivering a visual system that includes six screens, offering a 270-degree horizontal and 35-degree vertical FoV. And the company designed a system that is within the required footprint size, in part, by employing a JVC rear-screen projection system rather than an overhead projector, which could prove awkward for tall trainees in the simulator.

As required, the visual system also includes a "binocular" feature–a window that pops up on a screen to simulate a binocular-like, magnified image. "That image could also be made to fill an entire screen," says Asch. The TSS system also includes a separate visual system for the ground controllers, which is coordinated with the main, six-screen visual system.

Another challenging requirement is a voice recognition/voice synthesis system to accurately replicate voice communications between the controller and simulated aircraft. Trainees will not have to type in commands, but rather will able to "verbally tell the system what to do," according to Asch. Aircraft on the simulated visual will respond accordingly, just as in a real tower.

Equally important to the voice-recognition/synthesis system’s realism is that it also negates the need for pseudo pilots. Air Force officials explain that the use of pseudo pilots for tower training requires considerable manpower, and the service’s towers often have limited staffing.

"Most [voice recognition systems] require user training that runs from 10 to 30 minutes per student. With a large number of students, the need to train the system to recognize every user limits the system’s flexibility and produces additional resource overhead," says Asch. The TSS voice recognition system requires no user training and can recognize a person’s voice the moment he or she begins to speak, he contends.

A "critical" TSS requirement, according to Air Force officials, is aircraft recognition on the visual system. According to the acquisition description, the TSS system must have "a comprehensive database of aircraft flying standard maneuvers, as well as custom scenarios, [and that] allows for a flexible traffic environment that can be tailored to an individual controller’s training needs." This was accomplished for TSS through the high fidelity of modern simulator visual systems. "If you have a B-52 coming in to land, you will be able to make out that it is a B-52, even when it appears a long way from the airport," says Asch.

"We have a high number of aircraft models in the database, including even small Cessnas," he adds. "We can present a minumum of 13 aircraft per channel, and the system has six channels, so we can present up to 78 different aircraft simultaneously.

"The six channels, or personal computer image generators [PCIGs], serve the six live screens, which drive the information on the simulated display," Asch explains. A seventh PCIG provides the independent scene for the the ground controller.

Adacel created the high-definition, site-specific visual for the TSS simulator by "photographing everything in the environment, using both digital and analog cameras," says Asch. "We have thousands of photographs of items taken from all angles and during different times of the day." The photos are compiled and reproduced, using texture maps and polygons, to create three-dimensional models for site-specific imagery. The simulated scenes can appear as day or night imagery and in all types of weather conditions. Each of the 94 simulator databases will replicate the base environment in which it resides.

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