It's interesting--indeed, paradoxical--that while some members of the aviation industry will, during the next 12 months, be celebrating the arrival of glass cockpits in the coming very light jets, or VLJs, other industry members will be recalling the arrival of the first of these systems in civil aviation, little over a generation earlier. About 26 years ago, Boeing launched its trailblazing B757 and B767 passenger planes, incorporating a wide range of new technologies. Of these, avionics builder Collins' contribution to the Boeing program--which preceded Collins' merger with Rockwell--was a suite of color, cathode ray tubes (CRTs) showing flight control and engine instrument displays as electronic "pictures."
Described as electronic attitude direction indicators and electronic horizontal situation indicators (EADIs and EHSIs), the units were positioned on either side of two centrally located, vertically stacked CRTs, which formed the engine instrument and crew alerting system (EICAS). For commonality and fast exchange, the EADI, EHSI and EICAS displays were part-number identical. And instantly, industry adopted the term "glass cockpit."
That Was Then
But what a difference a generation makes. And what a dramatic impact the new avionics technologies, coupled with the new VLJ concepts, will have on our industry.
Over recent years a new wave of sleeker, faster aircraft has entered the general aviation market, many built by relatively new manufacturers. Most of these new aircraft will be jet-powered and owner-flown. But perhaps nothing better underlines VLJ technology than their flightdecks, which can truly be called glass cockpits.
Thanks to the entrepreneurial spirit of several smaller avionics companies--whose names were virtually unknown five years ago--a revolution in cockpit display concepts has occurred. Designers blended ideas from airline flightdecks and the computer industry in pilot-friendly combinations that break completely from traditional instrument configurations. Other than certain backup instruments, aviation's traditional round dials with their complex mechanisms and costly maintenance are being replaced by big, high-reliability, multifunction displays (MFDs) capable of presenting large amounts of data with a few computer-like keystrokes. For a small aircraft, what's unique is the integration of virtually all aircraft functions, including nonavionics systems such as deicing. All of the pilot's decisions are based on his operational flying knowhow and his knowledge of the airplane, which is funneled to him and from him through the glass displays.
Two companies are developing most of the integrated glass cockpit systems for the advanced VLJ market: Avidyne Corp. and Garmin International Inc. Avidyne is linked with the Eclipse 500 and Garmin with the Cessna Mustang, which appear to be leading contenders for the advanced VLJ stakes. Until now, most Avidyne and Garmin installations have been in the advanced piston twin and upper-end, single-engine markets. Typically, each company has offered its system in a dual, side-by-side, 10-inch display configuration, with a primary flight display (PFD) and associated MFD for shared left- and right-seat use. But for their VLJ configurations, Eclipse and Cessna have opted for centrally located 14- or 15-inch-wide MFDs, flanked by left- and right-hand PFDs. Both firms aim for a fully integrated VLJ.
The Eclipse 500 system was designed by a joint Avidyne/Eclipse team, with the "basic" Avidyne FlightMax Entegra as its starting point. The new configuration is uniquely called Avio, to recognize its significant differences from its FlightMax origins.
But it is too early to make comparisons between the two development efforts. Eclipse flew its first prototype in December 2004 and by April 2005 had five additional flight test aircraft nearing completion at its Albuquerque, N.M., factory. Meanwhile, the wing mating of Cessna's first Mustang conforming prototype occurred only in February in Wichita, Kan., with first flight tentatively scheduled for this month (May). Five Mustang prototypes are scheduled, but it was unclear which of these would receive the upgraded Garmin G1000 system. Avionics Magazine has not yet been briefed on the G1000.
The extent and complexity of modifying and upgrading a system like the FlightMax Entegra, to integrate all the operational attributes of a high-end VLJ, became abundantly clear during a three-hour system briefing for Avionics Magazine at Eclipse Aviation's assembly and flight test facility in Albuquerque.
Eclipse's Avio product manager, Matt Brown, stressed that today's advanced cockpits are just the beginning of a new era in aviation and that Avio is pioneering this movement to expand integration beyond the cockpit and distribute system "intelligence" throughout the aircraft. Yet in this highly automated, data-intensive environment, Avio's objective, says Brown, is to "only display information the pilot can do something about"--a breathtakingly attractive goal. Avio essentially becomes the aircraft's virtual copilot. For most pilots, this is far more glass cockpit technology than they have been used to, a fact that will call for intensive training. More on that later.
Brown describes the Avio design concept as typifying this total aircraft system integration approach, with the dual-redundant aircraft computer systems (ACS) as the "brains" and the electronic power distribution system (EPDS) as the "brawn."
Each ACS uses an array of analog and digital sensors, plus stepper motor outputs throughout the aircraft, linked by data bus communications and with cross-ACS data channels to provide redundancy management and multiple alternate data paths. Among other functions, the ACS controls and monitors power distribution, engine operating sequences, fuel, flaps, trim, landing gear, anti-ice/deice, brakes, internal/external lighting and environmental systems, autothrottle, and automatic flight control system, plus the recording of maintenance data. Each ACS unit also accommodates two full-authority digital engine control (FADEC) channels, with one for each engine but cross-channeled for redundancy.
Designed for Reliability
The aircraft's 24-volt DC electric power comes from a single 200-amp generator on each engine, plus two 24-volt DC, 24-amp/hour batteries. So you have four separate power sources feeding four main buses and two secondary buses of the EPDS. Power is further distributed through 127 electronic circuit breakers with solid state switching. All critical functions are fed from multiple buses, so that no single bus fault or circuit breaker failure results in the loss of any critical or essential function. The EPDS, states Brown, was designed to 10?9 reliability levels. That is, a 99.999999999 percent probability of correct operation, a level that is simply unprecedented in this class of airplane.
In most corporate and larger aircraft, an electronics bay houses the avionics units in a side-by-side, bookshelf-like manner where, like authors' names on books' spines, one can read off each individual manufacturer's name and each unit's nomenclature. This is no longer so.
Replacing Black Boxes
Pioneered in the Boeing 777 and now becoming common in most new airframes, yesterday's black boxes have been transformed into individual modules, and this is the case with Avio. So while the aircraft will have the usual dual com, nav, glideslope, GPS/wide area augmentation system (WAAS), transponder, attitude heading reference system (AHRS), and flight management computer, plus options like terrain awareness warning system (TAWS), Stormscope, automatic dependent surveillance-broadcast (ADS-B), DME, radio altimeter and Iridium satcom, few of these now are individually recognizable. Units that might once have been stored in the avionics bay now are packed into what resembles a computer card cage. The electronics are placed in various spaces inside the airframe, but virtually all black boxes have been reduced to circuit boards.
Yet Avio is in some areas still a work in progress. With customer deliveries still a year away, Brown's team is continually probing the current designs to squeeze out more technical efficiencies and other benefits. The team is conducting studies to evaluate tradeoffs, e.g. the human factors desirability of retaining a traditional pilot function vs. automating it over to Avio.
For example, the team is assessing the removal from Avio's MFD of traditional "idiot numbers," which most pilots consider to be a nuisance. Pilots traditionally learn these numbers--commonly engine temperatures and pressures--by rote. But without color wedges or other indicator marks, the numbers' values are virtually meaningless. Instead Avio is investigating color alerts that appear only when necessary.
What benefits will a true glass cockpit environment bring to general aviation? After all, no significant decrease in the airline accident rate ever has been attributed to the introduction of electronic display technology. In truth, of course, statistics don't help here. The key benefit is enhanced pilot situational awareness--not simply showing what's going on now, but what will happen in the future. Typical would be airline-like "trend" indicators that show where your present heading will put you 2, 4 or 6 seconds ahead, and whether your airspeed and/or altitude are increasing or decreasing, and at what rate. Another valuable situational awareness benefit would be the continuous display of the wind speed and direction at your present altitude, allowing instant comparison with the forecast wind you used for your flight plan. The goal, generally, is to reduce the need to continually monitor the gauges during flight. Avio includes these functions now, and Garmin probably will offer all of them.
On the other hand, both Chelton Flight Systems and Universal Avionics Systems Corp. have separately developed very tangible "highway in the sky" (HITS) presentations for their PFDs, which provide a visible lateral and vertical flight path framework along one's planned route, the sides of which decrease in perspective with distance ahead. Both companies also have developed synthetic vision systems (SVS), where the aircraft's current GPS position, track, heading, altitude and attitude are combined with an internal terrain database to produce a quite realistic presentation of the terrain ahead, as viewed from the flightdeck. Yet interestingly, while NASA has performed extensive flight tests with SVS variants, and is an enthusiastic supporter of its potential in general aviation, neither Avidyne nor Garmin offers that capability in the FlightMax Entegra or G1000 suites, and Avio's Brown had no comment on Eclipse's plans.
Down Side to Glass?
Is there a down side to the VLJs and their new glass cockpit technologies? In truth, yes.
For all their advanced display concepts and pilot-friendly systems, the VLJs will require a great deal of training, especially among less experienced owner/pilots. This includes, not just basic flight handling and aircraft familiarity, but understanding of the aircraft's systems and their interdependencies in all flight regimes. For many new owner/pilots, the VLJ's flight envelope will expose them--willingly or unwillingly--to flight environments they have not previously experienced but must be able to manage single-handedly and safely in the future.
High-speed, high-altitude flight operations, route planning, severe weather penetration, high-G upset recoveries, in-flight emergencies, flight profile management, and many other aspects of piloting will form a demanding training curriculum. Classroom work, simulator sessions and actual "hands-on" flying will test every would-be owner's capability.
Why should this training be so demanding? Look at past history. New, fast, highly maneuverable private aircraft like Bonanzas, Malibus and early Lears had serious accident rates when they were introduced: eight of the first 10 production Lear 23s were destroyed in crashes between 1963 and 1965. Yet only a few such aircraft were flying at that time, compared with the forecast tidal wave of thousands of VLJs entering the National Airspace System over the next decade.
Recognizing in the late 1990s that traditional pilot training methods were no longer adequate for new designs, FAA and industry specialists developed the FAA/Industry Training Standards (FITS), which would "ensure pilots learn to safely, competently and efficiently operate a technically advanced piston or light jet aircraft in the modern National Airspace System." Since then the FITS concept has been adopted in principle by all general aviation airframe companies, insurance underwriters and especially those building advanced designs. Concerns have been expressed, however, about the insurability of inexperienced/untrained pilots who wish to rent the new technology airplanes.
Such concerns are assured not to arise under Eclipse's training program, which, like those of all other VLJs, normally will be a mandatory condition of the aircraft purchase agreement. Eclipse is the only VLJ manufacturer that has so far described its training plan.
Eclipse has contracted with United Airlines to train customers at the carrier's Denver flight training center. Possession of a private pilot license, instrument rating and multiengine rating, and a review of the customer's pilot currency and overall qualifications, are prerequisites for entry to the training program. United pilot evaluators then assess the customer's instrument proficiency and airmanship skills in one of the airline's full-motion jet simulators. This is followed by an oral examination of judgment skills. If this evaluation is successful, the customer enters the FAA-approved Eclipse type rating transition course. If not, the customer is directed to obtain supplementary flight training elsewhere--with emphasis on specifically suggested flight regimes--to meet the type rating course entry standards. Following this additional training, the customer may reapply, at his own expense, for reevaluation to enter the type rating course.
The type rating course uses self-paced CD-ROM and Web learning, combined with Eclipse systems classroom training, high-speed jet upset recovery training (in a former Czech L-39 military fighter trainer), and sessions in purpose-built, fixed-base and full-motion Eclipse flight simulators. Instructor assessment at course completion will determine whether a customer should carry a mentor pilot, and for how long, although a mentor will be required for all pilots with no previous jet experience.
Six monthly recurrent training sessions, including home study, classroom work and flight simulator proficiency checks, will be required for customers with mentors, but at 12 monthly intervals for unmentored owners. Eclipse forecasts that both fixed-based and full-motion Model 500 flight simulators will be operational by mid-2006 at the United Airlines training center.
In the years ahead VLJs are expected to become a growing part of the traffic in the National Airspace System. Whether, as some have suggested, they will outnumber all other upper airspace users by 2020 is impossible to say. But unquestionably, the Eclipse initiative will have a profound influence on the way we fly in the future, and the technology we can expect to use to reach our destinations.
At A Glance
"Glass cockpits" are not new. Their roots can be traced back more than 25 years. But now a new breed of aircraft, the very light jets (VLJs), has expanded the glass cockpit "envelope" with new capabilities. Here is what makes the VLJ cockpits unique, along with their benefits and possible downsides.
Beyond providing flight, navigation and engine instrumentation data, the new cockpits are fully integrated to the airframe, and the display system serves as a "virtual copilot."
The black boxes that traditionally have been positioned bookshelf-like in the avionics bay have been replaced by circuit cards, or modules, in what resembles a computer card cage.
The main benefit of VLJ glass cockpits is enhanced situational awareness and the monitoring and control of the aircraft's many functions.
The main, potential downside to the VLJ cockpits is the amount of required flight training and the need to avoid the so-called "winged Ferrari syndrome."
'Glass Cockpits': Time for a New Definition?
Has the time arrived for the avionics industry to consider what is really meant by the term, "glass cockpit"? Today it is used to describe almost any electronic display on the instrument panel.
Consider these definitions:
Flightdecks in the Eclipse 500 and Cessna Mustang installations, aimed at full integration of the display system with the host airframe and most nonavionics systems, would fully qualify as glass cockpits.
The next tier down would include primary flight display/multifunction display (PFD/MFD) installations but with no or significantly less airframe integration.
The third tier would include all stand-alone PFDs--such as Chelton Flight System's electronic flight instrument system (EFIS)--that display at least aircraft attitude, airspeed, altitude and heading, and through which the aircraft can be controlled in all axes.
The fourth tier would include all other electronic displays--predominantly navigation presentations--all of which have individually been called glass cockpit devices in the past although their main purpose is usually to show current position against some sort of moving map.
The 'Winged Ferrari Syndrome'
"I shudder when I hear future potential customers talking about what they will be able to do once they get their `winged Ferrari,'" says one person who markets very light jets (VLJs). "They somehow don't seem to understand that while they can write a $650,000 check for an Enzo and promptly tear away up the interstate, that won't work for a VLJ."
The difference is that a new VLJ owner cannot expect to take delivery of his aircraft until all training requirements are fulfilled to the manufacturer's satisfaction, which could include the condition that the owner must carry a factory-approved "mentor" pilot for a given number of future flight hours.
Eclipse is the only VLJ manufacturer so far that has described its training plan. And if a customer pilot cannot successfully complete the training program, Eclipse will refund all past deposits. That, in part, should help mitigate the "winged Ferrari syndrome."