Simulating Reality

How advances in flight simulation technology are changing the way pilots train.

Simulating Reality Big

Simulating Reality Big

My goodness, it’s black out there.

“Better tighten your turn," my copilot says. "Those mountains are close.”

Yeah, but how close? I wonder. Checking the Cessna Citation Mustang’s terrain awareness and warning system provides cold comfort: The entire display is awash in red. The synthetic-vision system software update for this airplane, unfortunately, hasn’t yet been installed, so we’re on our own. Like an insidious mantra, a computer-generated voice continuously chimes in my headset: “Caution, terrain!”

The turbulence spilling across the mountains makes life all the more uncomfortable as the wind-speed readout on the Garmin G1000 primary flight display shows more than 60 knots off our right wing. Lightning flashes somewhere in the distance, and I instinctively crank the yoke over harder and — against my better judgment — continue the descent into Lugano Airport with the jagged, unseen Swiss Alps rising all around.

Why are we doing this?

Oh, yeah, we're not really being bounced around over southern Switzerland in a Citation Mustang. Instead, we're seated in the relative comfort of a Level-D full-motion simulator at FlightSafety International's newest learning center at Farnborough International Airport in southwest England. I have to keep reminding myself of this fact as Lugano's lighted runway at last comes into view and I line up on final. The illusory depth and texture of the simulated image mere feet in front of me certainly seems real enough. The firm clunk of the wheels on the concrete as we touch down feels right, and, exiting the left side of the runway, I can even detect the bumps and expansion joints beneath the wheels while taxiing to the ramp.

Advances in computing technology over the last several decades have certainly contributed to the amazing capability of today’s full-flight simulators, but that’s not the whole story. Motion systems are being converted from hydraulic to electric for improved fidelity and smoothness, and visual systems are advancing to the point that it can be hard to tell at a glance whether you’re looking out at a real world or not. Perhaps the only thing left that can take you out of the virtual experience of sitting at the controls of a simulator are those occasions when you can try things you’d never be brave enough — or dumb enough — to do in a real airplane.

Here’s what I mean: Invariably, whenever I climb into a new flight simulator or training device I’ve not seen before, I’m offered the invitation to perform a barrel roll. Or a loop. Or a hammerhead stall. Or, as has happened more than once, a macabre suggestion that we should crash — just to see what it’s like.

Truth be told, I don't want to do any of these things. When I'm evaluating a flight training device or simulator, I simply want to put the device through its normal regimen and experience the same sort of training scenarios that other pilots likely will during initial or recurrent training. Don't get me wrong. Rolling a Boeing 777 at Flight Level 350 for the first time is a hoot. It's just not very useful in making any kind of practical determination about the overall fidelity of a multimillion-dollar, six-degree-of-freedom full-flight simulator at an airline or corporate pilot training center. This is the kind of computing horsepower that, in theory, allows a pilot to earn a full type rating and head out to the line without ever spending any time behind the controls of the real airplane. Just flying the sim is enough.

Some of the most advanced full-motion flight simulators being produced today, in fact, can actually cost more to build than the real airplanes they are designed to mimic. And even the low-cost flight training devices being produced by companies like Redbird Flight Simulations, Elite Simulation Solutions and Fidelity Flight Simulation have become so incredibly sophisticated that they can accurately replicate not only the control laws of flight but also the operation of systems down to the deep button presses and menu selections on a Garmin or Avidyne glass cockpit. No longer are people asking whether new pilots should train in a simulator. Rather, it's become a question of how much training ought to be provided in the virtual environment.

What Time Counts?
Still, very few flight training devices are designed to teach the hows of flying. Most, instead, shine in their ability to more deeply ingrain rote cockpit procedures or in letting pilots experience predetermined emergency scenarios in the safety of a classroom or simulator setting. No wonder then that the FAA is proposing major changes to training standards that would mandate additional scenario-based simulator instruction for airline crews. The agency points to 178 commercial accidents from 1988 to 2009 resulting from inadequate training and operating procedures as justification for the changes. Those accidents, it says, resulted in 492 fatalities and more than 800 injuries.

The perceived value of simulator instruction also helps explain why the FAA now allows up to 20 hours of flying time toward an instrument rating to be conducted in a flight training device. Regulators feel so strongly about the value of simulator-based training, in fact, that they have written the rules to allow 25 hours toward an airline transport pilot certificate in approved simulators and 50 hours toward the commercial certificate. You can even complete certain elements of your commercial or ATP check ride in a simulator. But perhaps in an acknowledgment that simulators aren’t really intended to teach a new pilot how to fly, the FAA allows only 2.5 hours of sim time to count toward the private certificate.

Huge advances in simulation technology coupled with the FAA’s proposed training rule changes will serve only to make time spent in a simulator more commonplace for pilots just now rising through the ranks. For general aviation pilots, the shift to simulator training will translate to less out-of-pocket expense to earn certificates and remain current compared with time spent flying the real thing, since many flight schools charge only between $50 and $100 for hourly time in an FTD. Also, because simulators can be configured to let you complete tasks in rapid succession, you can squeeze in many more instrument approaches or maneuvers in a given block of time. That’s especially great news for pilots who find they have a hard time meeting the instrument proficiency requirements. Even better, you can satisfy the requirements without having to wear Foggles or bring along a safety pilot.

There are so many different types of flight simulators and training devices out there, however, that it can be hard to make sense of them all. At the bottom of the spectrum are games like Microsoft's Flight Simulator series, first introduced for the desktop PC more than 30 years ago, while at the top are NASA's space shuttle simulators, arguably the most advanced such devices ever conceived. (No surprise — a lot of simulation software is based on NASA's research.) In between lies a vast number of simulation devices. If you're confused about the differences between what the FAA calls an FSTD, FTD, PCATD, BATD and AATD, don't worry — they all can be demystified with a few bullet points. I promise your head won't hurt when you're finished.

Once you understand the intended purposes of the different types of training devices, you can make better decisions about the kind of simulator training that best fits your specific needs. Here’s a closer look at each type of training device:

Flight Simulator Training Device (FSTD) — These are the large full-flight simulators operated by airlines and companies like FlightSafety International and CAE Simuflite. Incorporating highly realistic flight modeling, systems and controls, these big-ticket devices feature top-notch visual presentations, accurate sound and the very best motion platforms the industry has yet to develop. Strap into one of these babies, and you might have a hard time believing you aren't somehow smashing a hole through the side of the simulator bay as you streak toward the flight levels.

Flight Training Device (FTD) — One rung down in sophistication are FTDs, which are used to train pilots on specific families or models of aircraft. Most feature accurate aerodynamic and systems modeling but usually do not include motion. Still, this is the primary type of simulation device you'll find at many general aviation and airline training facilities. Frasca International has long been one of the best-known manufacturers of flight training devices.

Personal Computer Aviation Training Device (PCATD) — You can probably thank Bill Gates for this one, since it was Microsoft's Flight Simulator series that first demonstrated the value of a personal computer as an aviation teaching tool. The FAA approved the use of PCATDs in May 1997 for 10 hours of credit toward the 40 hours needed for an instrument rating. Their adoption introduced a new class of devices that weren't quite as good as flight training devices, but which still offered a level of realism that was far better than that of early professional flight simulators. Since PCATDs hit the scene, an entire industry has sprung up around them to supply PC pilots with yokes, rudder pedals, realistic instrument stacks and more. The most popular PCATDs are those sold by Elite Simulation Solutions and Aviation Supplies & Academics, both of which focus on instrument training and proficiency.

Basic Aviation Training Device (BATD) — Advances in PC technology in the last decade led to the creation of an FAA advisory circular in July 2008 outlining the requirements for approval of two new types of simulator, the Basic Aviation Training Device (BATD) and Advanced Aviation Training Device (AATD). These two new classes of devices replaced the PCATD and some FTDs, while also giving welcome rise to a more streamlined approval process, including clearer guidance on how pilots could use such devices in training.

BATDs are similar to PCATDs, yet they have stricter hardware and software requirements. For example, BATDs must provide physical flight and aircraft systems controls (instead of interfaces like keyboards, mice and joysticks) and they must model the ergonomics of at least one aircraft in the family represented. Flight characteristics should be comparable to the simulated aircraft, although control loading does not have to model a specific aircraft. BATDs are approved for logging 2.5 hours toward the private pilot certificate and 10 hours toward the instrument rating and the required approaches, holds and tracking for instrument currency.

Advanced Aviation Training Device (AATD) — AATDs are comparable to what the FAA used to call a Level 3 flight training device. In addition to the standards required for BATDs, these advanced devices must replicate a particular category and class of aircraft cockpit. AATDs are approved for the full gamut of what the FAA allows of a PC-based training device, including: logging 2.5 hours toward the private certificate; logging 20 hours toward the instrument rating; completing certain elements of the instrument rating practical test; logging instrument experience for currency; completing instrument proficiency checks (except circle-to-land); logging 50 hours toward the commercial pilot certificate; completing certain elements of the commercial pilot practical test; logging 25 hours toward the ATP certificate; completing certain elements of the ATP certificate practical test; and logging simulated flight experience.

Most of the top-selling AATDs being built today feature wraparound visual screens, and some even incorporate motion. Redbird Flight Simulations’ FMX advanced trainer, for example, features an enclosed wraparound cockpit and quick-change capability to switch from single-engine to multiengine and from traditional to glass cockpits, as well as an excellent six-degree-of-freedom electric motion platform.

The Future of Simulation
Many flight training devices have incorporated motion for decades, with the Link Trainer produced between the early 1930s and early 1950s being the best-known example. As early as 1910, however, pilots were using rudimentary flight demonstration devices consisting of two barrel halves cut lengthwise and placed atop a wooden platform. Pilots would sit in the uppermost barrel and manually move the half sections to represent the pitch and roll of an airplane, lining up a reference bar with the horizon. The Link Trainer used mechanical pumps, valves and bellows to move the device in response to control inputs that accurately matched a basic set of flight instruments.

After the 1950s, hydraulic-based motion systems emerged as the preferred technology, despite notorious reliability problems that required training providers to keep mechanics standing at the ready to fix broken devices. Simulator manufacturers started switching over to electric-based motion and control loading systems in the last decade, representing one of the major breakthroughs in recent simulator design. Not only do electric-based motion systems require less maintenance, but they are also quieter, smoother and more precise than hydraulic-based simulators.

It’s easy to add electric actuators to a simulator. The hard part is controlling them with precision. Software engineers must work to make cockpit controls respond exactly as they do in the real aircraft. Simulators built by FlightSafety and CAE, for instance, use control-sensor sample motions of many thousand times per second to provide realistic stick and pedal feel with smoothness that wasn’t possible in the past with hydraulics.

Thanks to electric systems, the benefits of motion are starting to trickle down to general aviation. While it's true flight simulators aren't really intended to teach pilots how to fly, more and more of them can, such as Redbird's Xwind, a unique motion-based simulator that is intended to accurately mimic crosswind during the landing flare. With its major rewrite of airline training rules, the FAA wants air carriers to use full-motion Level-D simulators to teach pilots how to recognize and recover from stalls. For decades, airline pilot training has focused on avoiding aerodynamic stalls at all costs, with little attention placed on proper stall recovery techniques. After the crash of Colgan Air Flight 3407 on approach to Buffalo, New York, in February 2009, the FAA added stall training scenarios to its proposed training mandate.

Advances are being made even in flight training devices that don't incorporate motion. Cessna, for example, recently launched the Guided Independent Flight Training (GIFT) program in collaboration with King Schools and Redbird. Available exclusively at Cessna Pilot Centers, GIFT simulator training covers all private pilot maneuvers, from steep turns and traffic pattern entries to short field takeoffs and landings. One of the best aspects of the program is that students don't need to schedule an instructor for their simulator sessions. Instead, they watch John or Martha King demonstrate each maneuver from different video viewpoints on the simulator's visual display and then try it out for themselves. As the student practices the maneuver, the program provides feedback by measuring real-time performance against the private pilot practical test standards.

The innovation doesn’t end there. Pilots start their sim sessions by logging in with a special USB data card. This configures the simulator and GIFT, compiling the pull-down maneuver menu appropriate to the student’s current level of training. It also records the student activity and performance, which instructors can review at their convenience, just as they can with Cessna’s online ground school program. GIFT isn’t intended to replace instructors, Cessna says, but instead to add value to the time they spend with students in flight. “This is another way we are working to lower the time and cost of flight training while exploiting technology to continue to improve the quality of training through our network,” Cessna Pilot Center manager Julie Filucci says.

With the growing understanding on the part of regulators that simulator training can help operators make inroads on improving safety, with computer and display technology becoming more sophisticated and less expensive all the time, and with growing market pressure from customers for cost-effective training, it’s safe to say that the revolution in simulator technology and its widespread adoption have nowhere to go but up.