Cockpit displays have come a long, long way in just a few short years. From the one-line monochrome text of the GPS displays of the early 1990s, we have now progressed to ever-larger, more content-rich screens showing a variety of flight information. Screens went from four and five inches in diagonal size to today's 14-inch models. Content has shifted from single-source displays showing only, for example, navigation information, to technicolor arrays that lay out a multitude of datasets. Round mechanical "steam gauges" of the past are rapidly leaving today's cockpits, and tomorrow's panels likely won't have any round gauges at all—save perhaps those that serve as emergency backups.
All this technological progress was brought to us by the miniaturization of cathode ray tubes (CRTs) and liquid-crystal displays (LCDs). The first "glass cockpits" to use this technology seemed faddish in its application. The Beech Starship comes to mind—an airplane with a whopping 16 electronic displays. And almost every one was an electronic duplicate of a traditional electromechanical gauge—say, an RMI or HSI.
But it didn't take long for engineers to combine information sources into what came to be called electronic flight information systems (EFISs) and apply them to ever-larger screens, which is today's state of the art. Now we have eight- by 10-inch—or larger—primary flight displays (PFDs) parked in front of the pilot (and, for a price, the copilot, too) and multifunction displays (MFDs) located in the central portions of the instrument panel.
The PFDs typically combine attitude and navigation information posted in the center of the screens, with airspeed, altitude, and vertical velocity information lined up along the edges of the display using the vertical-tape display format. Carats and pointers along those tapes show how fast you're flying, climbing, or descending—and in some installations, how fast or high you'll be in the next 10 seconds. These are called predictive trend lines. Of course, providing all this information requires some type of attitude and heading reference (AHRS) unit to generate rate of acceleration, turn, and other positional information. Old-fashioned spinning gyros just won't do. An air data computer is also needed to provide correct speed, track, and time-distance calculations. And, of course, a GPS or other flight management system (FMS) is necessary for navigation inputs.
MFDs are set up to show engine readings and the status of the airplane's systems, and can also provide plan-view diagrams of such things as the flight-planned route and radar imagery.
Up to now, PFDs and MFDs have resided in newer business jets, with the Collins Pro Line and Honeywell Primus series of displays leading the way. But no more. A whole range of displays has begun to permeate all ranks of general aviation airplanes.
Egged on by the success of Garmin's 430 and 530 big-screen GPS navigation displays, manufacturers have begun to come up with increasingly capable integrated displays. Avidyne Corporation, for example, has come out with its Flight Max 740 and 850 flight situation displays. The 850 can present on-board radar, TCAS, BFGoodrich Skywatch, Ryan TCAD, ground poximity warning alerts, lightning data, and GPS-derived navigation and flight plan information, all superimposed on a five-inch color screen. The 740 is for airplanes without radar, but this unit is set up to receive uplinked services—including weather imagery.
Honeywell-Bendix/King's latest offering is the IHAS (integrated hazard avoidance system) 8000. This uses the company's KMD 850 MFD to show terrain, weather radar, traffic, and navigation information on a five-inch screen. A sister system, the IHAS 5000, is intended for use in airplanes without airborne weather radar—like the Flight Max 740.
Another Honeywell avionics suite, the Primus Epic system, will debut on the Raytheon Horizon and Sino-Swearingen SJ30-2 business jets in 2002. This system uses eight-by- 10-inch screens to show flight and navigation information (including terrain depiction on the PFDs), and also features a touch-screen operating system that can be used to operate components of an airplane's systems, just by pointing or clicking on a fuel valve, say, or a cabin temperature-control symbol. Epic engineers are even working on a voice-recognition system that will allow pilots to tune radios and transponders by merely speaking the desired sequence of numbers.
The Honeywell Primus 2000XP is another noteworthy cockpit suite. It includes such advanced features as the ability to view control surface deflections on an MFD as pilots manipulate the ailerons, spoilers, elevators, and rudder. Bombardier's Global Express uses this suite.
Sierra Flight Systems' EFIS displays are also worth mentioning. This setup includes a PFD, ND (navigation display), ED (engine display), and EAU (engine/air data unit) that utilizes a 6.5-inch screen and even includes a vocal warning capability that can alert pilots to such hazards as high engine temperatures or low oil pressures.
Meggitt Avionics' Magic system (soon to debut on the New Piper Meridian) is another new EFIS provider. This package includes two primary flight displays, an engine display, and a digital AHRS.
At the latest Sun 'n Fun EAA Fly-In, Avrotech Avionics showed off its pair of new displays in a mockup of a Lancair Columbia 300—and the technology successfully guided Lancair's new Columbia 400 from Bend, Oregon, to Oshkosh. Driven by Avidyne software, these huge displays provided a great deal of integrated information in easy-to-read formats.
None of this is to disparage the standalone displays that come with such great navigation or surveillance units as Eventide's Argus 3000 and 5000, Sandel's electronic HSI, or BFG's TCAS/Skywatch and Stormscope. It's just that these products are smaller, and each addresses a single function. In the future, the trend is definitely toward larger, integrated displays.
Using the UPSAT MX20 navigation display and GX60 GPS unit, the FAA is currently testing yet another means of traffic avoidance—the use of ADS-B imagery. What's ADS-B? It stands for Automatic Dependent Surveillance-Broadcast, and under its scheme air traffic control symbology is uplinked to aircraft with the necessary antennas and hardware. The symbology appears on the MX-20, and pilots can see in an instant where and how any traffic conflicts may come about. Ground-based radar imagery can also be uplinked to the test aircraft, which are currently flying in Alaska under a demonstration program called Capstone. In the future, ADS-B will augment conventional ATC services, permitting more direct routings under the "free flight" concept that many assume will be the future navigation method of choice. Meanwhile, the displays of the future will all be capable of depicting ADS-B traffic returns.
Since the mid-1990s, NASA's AGATE (Advanced General Aviation Transport Experiments) program has been testing various ideas for the cockpits of tomorrow. One of them is what has come to be called the "highway in the sky" (HITS) concept—a concept first advanced in the 1960s by California aeronautical engineer George Hoover. This involves reducing pilot workload by providing an altogether new concept in navigation technology. The pilot views a series of rectangular symbols that trail along a flight-planned route. Fly through this series of boxes and you'll navigate like a pro, from takeoff to touchdown, VFR or IFR (the boxes can also be driven by ILS signals).
In its highest evolution, HITS would involve a three-dimensional type of display, one that would faithfully depict the terrain around the airplane, show any conflicting traffic, and show symbols for nearby lightning or precipitation returns—all on the same screen.
Of course, to show all this information a large screen—or screens—is necessary. These were the kind of 10.4-inch screens that were on display at BFG's booth at this year's EAA AirVenture in Oshkosh. BFG's new SmartDeck lets pilots select a HITS feature, or fly a conventional attitude indicator on the system's PFD. With HITS, you can fly in a kind of synthetic vision, where you "fly through" waypoints and their identifiers as you wind your way through the sky, flying within a box that represents 600 feet across and 400 feet high. There are no conventional round gauges in sight. On the MFD, you can tune radios, call up datalinked graphic or text weather information, or study approach plates or runway diagrams. Vertical tapes are used for airspeed, vertical speed, and altitude, and the MFD has an engine-monitoring function. The SmartDeck, inspired by AGATE, is to be certified in 2002 and will sell for some $60,000. More than anything else in the GA market, SmartDeck represents the fruition of the AGATE idea and the future of high-end avionics.
Two good questions. In many cases these avionics suites and displays are so new that price tags have yet to be assigned. However, a good ballpark range for a full-up suite of displays, avionics, and reference units of the types discussed here would be from $30,000 to $60,000, plus installation. That's a lot of money, but think of what you'll get in return: workload-easing displays, more reliable equipment, and in virtually all cases, reference units with mean times between failure in the tens of thousands of hours, replacing unreliable conventional gyros. Situational awareness and resale value go up, and the chance of an adverse weather encounter goes way down. Is all this worth it? You bet. And anyway, the question may be moot by 2005, when displays of this nature begin to appear on a widespread scale.
With such sophisticated displays, such reliability, such interactivity of so much information, what problems could these new cockpits pose? For one, teaching pilots how to use such complex systems. Today's flight instructors have a hard time teaching their students how to use today's batch of GPS receivers, let alone a full-blown integrated flight-control system. Another issue is the degradation of basic pilot skills. It's already been shown that GPS navigation has spoiled most of us so badly that our pilotage and VOR navigation skills are deteriorating. Another concern is the heavy reliance on electrical power, symbol generators, and other electrical components. This means that an electrical failure could bring down the whole house of cards.
Therefore, secondary sources of electrical power and AHRS information will be necessary. Without any of the old round gauges for comparison or emergency purposes, we'd be totally dependent on single-source systems, although reversionary modes will allow pilots to work around a failed display by switching its imagery to an operating display screen.
Last but certainly not least, there's the problem of fixation. These new displays look great and have tremendous advantages, but they suck your attention right into the instrument panel. The downside: too much heads-down, and no one looking outside. This is already a problem with today's FMSs and wall-to-wall glass cockpits. What happens when you're so preoccupied with flying the highway-in-the-sky that you miss a critical event—like a nontransponder-equipped airplane about to go through your altitude? In a recent history marked almost exclusively by progress in avionics sophistication, questions like these can't be ignored.
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