New visual and actuator systems are blurring the line between up there and down here while keeping costs down to earth.
AL PALMER, DIRECTOR OF FLIGHT operations for the University of North Dakota, is so impressed with his new Frasca 342 flight training device (FTD) that he’s requesting a big concession from the FAA–a quantum increase in the amount of time that the device can be used toward a helicopter pilot’s instrument instructor ticket.
Currently a pilot can use the device for 20 percent of the hours needed for the ticket. Palmer is asking for 50-50 split between actual and synthetic flight. "Those rules were written years ago," he said. "Now, FTDs are extremely realistic. Why shouldn’t we do more in FTDs than in the real aircraft?"
North Dakota leased the $750,000 Frasca 342, which emulates the Bell 206 or Schweizer 300 and comes complete with all visual and auditory effects but no base motion–on Aug. 18, and had already logged 50 hr. as of Sept. 18. "It’s really a step ahead of anything we’ve ever had for helicopters," he said.
What Palmer is experiencing is the leading edge of a new breed of flight training devices and simulators (full-motion devices) infused with of a wide array of technology upgrades. The overall effect has been to increase the fidelity of the training experience while decreasing the cost of owning and operating the equipment. FTDs in particular could spawn safety gains in the civil helicopter industry by allowing a larger percentage of the pilot population to have access to lower-cost ground based training in emergency procedures.
North Dakota had been using FTDs for its fixed-wing program for years, but the devices were not available for rotorcraft until recently. Instead, the school was using cockpit procedures trainers for some of the instrument work and live aircraft for the bulk of it. The flight school trains Army ROTC cadets (allowing them to bypass 20 weeks of basic helicopter training at Fort Rucker and go directly to advanced training), as well as fixed-wing and helicopter pilots for the Saudi oil company Aramco and "walk-ins", students who come to the school and pay their way to learn to fly helicopters. Palmer said he wanted to get a simulator to do more than teach procedures. "We wanted a fairly sophisticated device with a specific cockpit, high visual quality and modern avionics," he said. Palmer began working with Frasca last summer to come up with such a system.
It turns out that Frasca was in a good position to offer a solution. A few years earlier, Embry-Riddle Aeronautical University had come to Illinois-based company with a "pretty demanding requirement" of its owns, said Frasca vice president, John Frasca. Embry-Riddle wanted to "revolutionize" how they were training fixed wing ab initio students. As such, they wanted a cockpit that looked like the actual aircraft and they wanted a horizontal visual field of 220 deg. Simulators at the time had 120-to-150-deg. visual systems with 30 deg. in the vertical. While Embry-Riddle did not specify its vertical requirement, Frasca decided 60 deg. was needed to be able to "see" the runway while flying in the traffic pattern. From a technology standpoint, the key problems that had to be worked out involved image warping and image blending from three image generators (from three separate channels) and three screens mounted to the wraparound dome over the cockpit.
Frasca’s helicopter clients saw the product and liked it, but asked for more visual in the vertical to be able to simulate emergency maneuvers and long-line work. Frasca came up with a fourth channel below the helicopter that opened the visual field to 110 deg. "You can stick your head out of the cockpit and look below," said Frasca. The idea took hold with offshore oil transport companies like Petroleum Helicopters and Air Logistics, and for training operations like Bell Helicopter’s Customer Training Academy. Among other uses, the companies could accurately perform emergency procedures like autorotations to the ground or simulate approaches to oil platforms in any kind of weather on a device costing about 30 times less than the Level D simulators previously needed to do such training.
Confluence of Technologies
Frasca said the confluence of technologies paved the way for the new systems. While previous flight training devices could computationally handle highly dynamic situations like autorotations, the visual cues weren’t adequate to fly to the ground. Because the visual technology wasn’t ready, there was no need to push for higher fidelity aerodynamic models and landscape databases. "There’s no sense having $1,000 speakers in your stereo if you have a hundred-dollar amplifier," said Frasca. With the arrival of higher accuracy projectors however, it made sense to increase the fidelity of aerodynamic models and the resolution of the terrain database. Frasca said the company generally maps the terrain to 1 m. in a 1-km. region around airports of interest while the enroute portion might be 10-15 m. "We’re finding customers want to fly lower and get 5-m., 2-m. or 1-m. data," he said, adding, "Data is available in most cases, but someone has to pay for it." Audio systems have also made large strides through digital sampling and computer-controlled playback of real aircraft sounds. Frasca said the method is far superior to the audio solution of the past – synthesized sounds.
FlightSafety International is also advancing its military and civilian Level D simulators by cutting down production time with increased modularity while boosting fidelity and lowering operating expenses with electric actuators. The improvements are featured on 35 new TH67 and Blackhawk Level D-equivalent simulators on tap for the U.S. Army’s Flight School XXI program at Fort Rucker. John Slish, manager of product information for FlightSafety, said the company has delivered 20 simulators so far.
While FlightSafety’s legacy units were built in piece-card fashion – assemblies built up from "bits and pieces" – Slish said the new systems are of a "very deep modular design." Enhancing the clean design are FlightSafety`selectric actuators, used for the control loading and motion systems. "There are no accumulators, no plumbing. There are six big cables and six little cables – the big cables are power, the little cables are signal," he said.
While FlightSafety has been using electric actuators for control loading for 10 years, the challenge was in moving to electrical actuators, as opposed to the tried and true hydraulics, for the base. Due to the range of motion, the each actuator had to be capable of supporting the 16-ton simulator on its own yet had to have the fidelity to precisely control the motion. FlightSafety teamed with Moog to build the new actuators, which are now offered on military C17 and Flight School XXI simulators but not yet on civilian units.
Slish said that in addition to being "exceptionally quiet" and less costly than their hydraulic counterparts, the electric base actuators use 40 percent less electricity. The upgrade is not exclusive to new simulators either: Slish said FlightSafety can retrofit the electric actuators into any FlightSafety hydraulic base system in just 8 hr.