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66-518: On the flight deck, the display units are the most obvious parts of an EFIS system, and are the features that lead to the term glass cockpit . The display unit that replaces the artificial horizon is called the primary flight display (PFD). If a separate display replaces the HSI, it is called the navigation display. The PFD displays all information critical to flight, including calibrated airspeed , altitude, heading, attitude, vertical speed and yaw. The PFD

132-399: A trackball , thumb pad or joystick as a pilot-input device in a computer-style environment. Many of the modifications offered by the aircraft manufacturers improve situational awareness and customize the human-machine interface to increase safety. Modern glass cockpits might include synthetic vision systems (SVS) or enhanced flight vision systems (EFVS). Synthetic vision systems display

198-506: A transformer whose primary-to-secondary coupling may be varied by physically changing the relative orientation of the two windings. Synchros are often used for measuring the angle of a rotating machine such as an antenna platform or transmitting rotation. In its general physical construction, it is much like an electric motor. The primary winding of the transformer, fixed to the rotor , is excited by an alternating current , which by electromagnetic induction causes voltages to appear between

264-538: A backup battery. In 2010, the NTSB published a study done on 8,000 general aviation light aircraft. The study found that, although aircraft equipped with glass cockpits had a lower overall accident rate, they also had a larger chance of being involved in a fatal accident. The NTSB Chairman said in response to the study: Training is clearly one of the key components to reducing the accident rate of light planes equipped with glass cockpits, and this study clearly demonstrates

330-417: A bar drops across the erroneous data. EFIS, on the other hand, removes invalid data from the display and substitutes an appropriate warning. A de-clutter mode activates automatically when circumstances require the pilot's attention for a specific item. For example, if the aircraft pitches up or down beyond a specified limit—usually 30 to 60 degrees—the attitude indicator de-clutters other items from sight until

396-679: A congested instrument panel. They are also lighter, and occupy a lower volume. The MFD (multi-function display) displays navigational and weather information from multiple systems. MFDs are most frequently designed as "chart-centric", where the aircrew can overlay different information over a map or chart. Examples of MFD overlay information include the aircraft's current route plan, weather information from either on-board radar or lightning detection sensors or ground-based sensors, e.g., NEXRAD, restricted airspace and aircraft traffic. The MFD can also be used to view other non-overlay type of data (e.g., current route plan) and calculated overlay-type data, e.g.,

462-438: A control synchro system is a system in which the transmitted signal controls a source of power which does the usable work. Quite often, one system will perform both torque and control functions. Individual units are designed for use in either torque or control systems. Some torque units can be used as control units, but control units cannot replace torque units. A synchro will fall into one of eight functional categories: On

528-523: A control transformer (CT), is part of a position servo that includes a servo amplifier and servo motor. The motor is geared to the CT rotor, and when the transmitter's rotor moves, the servo motor turns the CT's rotor and the mechanical load to match the new position. CTs have high-impedance stators and draw much less current than ordinary synchro receivers when not correctly positioned. Synchro transmitters can also feed synchro to digital converters, which provide

594-420: A course deviation indicator to show the planned track provided by an area navigation or flight management system. Pilots can choose to superimpose the weather radar picture on the displayed route. The flexibility afforded by software modifications minimises the costs of responding to new aircraft regulations and equipment. Software updates can update an EFIS system to extend its capabilities. Updates introduced in

660-403: A digital representation of the shaft angle. So-called brushless synchros use rotary transformers (that have no magnetic interaction with the usual rotor and stator) to feed power to the rotor. These transformers have stationary primaries, and rotating secondaries. The secondary is somewhat like a spool wound with magnet wire, the axis of the spool concentric with the rotor's axis. The "spool"

726-401: A practical level, synchros resemble motors, in that there is a rotor, stator, and a shaft. Ordinarily, slip rings and brushes connect the rotor to external power. A synchro transmitter's shaft is rotated by the mechanism that sends information, while the synchro receiver's shaft rotates a dial, or operates a light mechanical load. Single and three-phase units are common in use, and will follow

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792-650: A realistic 3D depiction of the outside world (similar to a flight simulator ), based on a database of terrain and geophysical features in conjunction with the attitude and position information gathered from the aircraft navigational systems. Enhanced flight vision systems add real-time information from external sensors, such as an infrared camera. All new airliners such as the Airbus A380 , Boeing 787 and private jets such as Bombardier Global Express and Learjet use glass cockpits. Many modern general aviation aircraft are available with glass cockpits. Systems such as

858-636: A serious glass-cockpit blackout, losing half of the Electronic Centralised Aircraft Monitor ( ECAM ) displays as well as all radios, transponders, Traffic Collision Avoidance System ( TCAS ), and attitude indicators. The pilots were able to land at Newark Airport without radio contact in good weather and daylight conditions. Airbus has offered an optional fix, which the US National Transportation Safety Board (NTSB) has suggested to

924-440: A true departure. They look and behave very similarly to other computers, with windows and data that can be manipulated with point-and-click devices. They also add terrain, approach charts, weather, vertical displays, and 3D navigation images. The improved concepts enable aircraft makers to customize cockpits to a greater degree than previously. All of the manufacturers involved have chosen to do so in one way or another—such as using

990-416: A two-speed link had two transmitters, one rotating for one turn over the full range (such as a gun's bearing), while the other rotated one turn for every 10 degrees of bearing. The latter was called a 36-speed synchro. Of course, the gear trains were made accordingly. At the receiver, the magnitude of the 1X channel's error determined whether the "fast" channel was to be used instead. A small 1X error meant that

1056-420: Is a similar system used by Airbus, which in addition to providing EICAS functions also recommend remedial action. EFIS provides pilots with controls that select display range and mode (for example, map or compass rose) and enter data (such as selected heading). Where other equipment uses pilot inputs, data buses broadcast the pilot's selections so that the pilot need only enter the selection once. For example,

1122-574: Is an aircraft cockpit that features an array of electronic (digital) flight instrument displays , typically large LCD screens, rather than traditional analog dials and gauges. While a traditional cockpit relies on numerous mechanical gauges (nicknamed "steam gauges") to display information, a glass cockpit uses several multi-function displays and a primary flight display driven by flight management systems , that can be adjusted to show flight information as needed. This simplifies aircraft operation and navigation and allows pilots to focus only on

1188-416: Is armed, and capture might change the color to green. Typical EFIS systems color code the navigation needles to reflect the type of navigation. Green needles indicate ground-based navigation, such as VORs, Localizers and ILS systems. Magenta needles indicate GPS navigation. EFIS provides versatility by avoiding some physical limitations of traditional instruments. A pilot can switch the same display that shows

1254-417: Is designed to improve a pilot's situational awareness by integrating this information into a single display instead of six different analog instruments, reducing the amount of time necessary to monitor the instruments. PFDs also increase situational awareness by alerting the aircrew to unusual or potentially hazardous conditions — for example, low airspeed, high rate of descent — by changing

1320-682: Is possible because of steep drops in the price of sensors and displays, and equipment for experimental aircraft doesn't require expensive Federal Aviation Administration certification. This latter point restricts their use to experimental aircraft and certain other aircraft categories, depending on local regulations. Uncertified EFIS systems are also found in Light-sport aircraft , including factory built, microlight, and ultralight aircraft. These systems can be fitted to certified aircraft in some cases as secondary or backup systems depending on local aviation rules. Glass cockpit A glass cockpit

1386-533: Is produced by the symbol generator. This receives data inputs from the pilot, signals from sensors, and EFIS format selections made by the pilot. The symbol generator can go by other names, such as display processing computer, display electronics unit, etc. The symbol generator does more than generate symbols. It has (at the least) monitoring facilities, a graphics generator and a display driver. Inputs from sensors and controls arrive via data buses, and are checked for validity. The required computations are performed, and

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1452-581: Is reflected in the total acceptance of electronic flight displays. The safety and efficiency of flights have been increased with improved pilot understanding of the aircraft's situation relative to its environment (or " situational awareness "). By the end of the 1990s, liquid-crystal display (LCD) panels were increasingly favored among aircraft manufacturers because of their efficiency, reliability and legibility. Earlier LCD panels suffered from poor legibility at some viewing angles and poor response times, making them unsuitable for aviation. Modern aircraft such as

1518-401: Is simple: Is roll data (bank angle) from sensor 1 the same as roll data from sensor 2? If not, display a warning caption (such as CHECK ROLL ) on both PFDs. Comparison monitors give warnings for airspeed, pitch, roll, and altitude indications. More advanced EFIS systems have more comparator monitors. In this technique, each symbol generator contains two display monitoring channels. One channel,

1584-430: Is the secondary winding's core, its flanges are the poles, and its coupling does not vary significantly with rotor position. The primary winding is similar, surrounded by its magnetic core, and its end pieces are like thick washers. The holes in those end pieces align with the rotating secondary poles. For high accuracy in gun fire control and aerospace work, so called multi-speed synchro data links were used. For instance,

1650-475: Is to use one large screen to show both the PFD and navigation display. The PFD and navigation display (and multi-function display, where fitted) are often physically identical. The information displayed is determined by the system interfaces where the display units are fitted. Thus, spares holding is simplified: the one display unit can be fitted in any position. LCD units generate less heat than CRTs; an advantage in

1716-563: The Boeing 737 Next Generation , 777 , 717 , 747-400ER , 747-8F 767-400ER , 747-8 , and 787 , Airbus A320 family (later versions), A330 (later versions), A340-500/600 , A340-300 (later versions), A380 and A350 are fitted with glass cockpits consisting of LCD units. The glass cockpit has become standard equipment in airliners , business jets , and military aircraft . It was fitted into NASA's Space Shuttle orbiters Atlantis , Columbia , Discovery , and Endeavour , and

1782-604: The Diamond DA42 . The Lockheed Martin F-35 Lightning II features a "panoramic cockpit display" touchscreen that replaces most of the switches and toggles found in an aircraft cockpit. The civilian Cirrus Vision SF50 has the same, which they call a "Perspective Touch" glass cockpit. Unlike the previous era of glass cockpits—where designers merely copied the look and feel of conventional electromechanical instruments onto cathode-ray tubes—the new displays represent

1848-576: The Garmin G1000 are now available on many new GA aircraft, including the classic Cessna 172 . Many small aircraft can also be modified post-production to replace analogue instruments. Glass cockpits are also popular as a retrofit for older private jets and turboprops such as Dassault Falcons , Raytheon Hawkers , Bombardier Challengers , Cessna Citations , Gulfstreams , King Airs , Learjets , Astras , and many others. Aviation service companies work closely with equipment manufacturers to address

1914-724: The McDonnell Douglas MD-80 , Boeing 737 Classic , ATR 42 , ATR 72 and in the Airbus A300-600 and A310 , used electronic flight instrument systems (EFIS) to display attitude and navigational information only, with traditional mechanical gauges retained for airspeed, altitude, vertical speed, and engine performance. The Boeing 757 and 767-200/-300 introduced an electronic engine-indicating and crew-alerting system (EICAS) for monitoring engine performance while retaining mechanical gauges for airspeed, altitude and vertical speed. Later glass cockpits, found in

1980-475: The attitude indicator and horizontal situation indicator (HSI). However, the 2707 was cancelled in 1971 after insurmountable technical difficulties and ultimately the end of project funding by the US government. The average transport aircraft in the mid-1970s had more than one hundred cockpit instruments and controls, and the primary flight instruments were already crowded with indicators, crossbars, and symbols, and

2046-566: The integrated standby instrument system . Glass cockpits originated in military aircraft in the late 1960s and early 1970s; an early example is the Mark II avionics of the F-111D (first ordered in 1967, delivered from 1970 to 1973), which featured a multi-function display . Prior to the 1970s, air transport operations were not considered sufficiently demanding to require advanced equipment like electronic flight displays. Also, computer technology

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2112-458: The 1990s included the ground proximity warning system and traffic collision avoidance system . A degree of redundancy is available even with the simple two-screen EFIS installation. Should the PFD fail, transfer switching repositions its vital information to the screen normally occupied by the navigation display. In the late 1980s, EFIS became standard equipment on most Boeing and Airbus airliners , and many business aircraft adopted EFIS in

2178-533: The 1990s. Recent advances in computing power and reductions in the cost of liquid-crystal displays and navigational sensors (such as GPS and attitude and heading reference system ) have brought EFIS to general aviation aircraft. Notable examples are the Garmin G1000 and Chelton Flight Systems EFIS-SV. Several EFIS manufacturers have focused on the experimental aircraft market, producing EFIS and EICAS systems for as little as US$ 1,000-2000. The low cost

2244-401: The 36x channel's data was unambiguous. Once the receiver servo settled, the fine channel normally retained control. For very critical applications, three-speed synchro systems have been used. So called multispeed synchros have stators with many poles, so that their output voltages go through several cycles for one physical revolution. For two-speed systems, these do not require gearing between

2310-673: The Boeing 737NG , 747-400 , 767-400 , 777 , Airbus A320 , later Airbuses, Ilyushin Il-96 and Tupolev Tu-204 have completely replaced the mechanical gauges and warning lights in previous generations of aircraft. While glass cockpit-equipped aircraft throughout the late 20th century still retained analog altimeters , attitude , and airspeed indicators as standby instruments in case the EFIS displays failed, more modern aircraft have increasingly been using digital standby instruments as well, such as

2376-462: The EICAS might sound an alert, switch the display to the page with the oil system information and outline the low oil pressure data with a red box. Unlike traditional round gauges, many levels of warnings and alarms can be set. Proper care must be taken when designing EICAS to ensure that the aircrew are always provided with the most important information and not overloaded with warnings or alarms. ECAM

2442-676: The Russian Soyuz TMA model spacecraft that were launched for the first time in 2002. By the end of the century glass cockpits began appearing in general aviation aircraft as well. In 2003, Cirrus Design 's SR20 and SR22 became the first light aircraft equipped with glass cockpits, which they made standard on all Cirrus aircraft. By 2005 , even basic trainers like the Piper Cherokee and Cessna 172 were shipping with glass cockpits as options (which nearly all customers chose), as well as many modern utility aircraft such as

2508-588: The US Federal Aviation Administration (FAA) as mandatory, but the FAA has yet to make it a requirement. A preliminary NTSB factsheet is available. Due to the possibility of a blackout, glass cockpit aircraft also have an integrated standby instrument system that includes (at a minimum) an artificial horizon , altimeter and airspeed indicator . It is electronically separate from the main instruments and can run for several hours on

2574-685: The Y-connected secondary windings fixed at 120 degrees to each other on the stator . The voltages are measured and used to determine the angle of the rotor relative to the stator. Synchro systems were first used in the control system of the Panama Canal in the early 1900s to transmit lock gate and valve stem positions, and water levels, to the control desks. Fire-control system designs developed during World War II used synchros extensively, to transmit angular information from guns and sights to an analog fire control computer , and to transmit

2640-447: The aircraft's systems, including its fuel, electrical and propulsion systems (engines). EICAS displays are often designed to mimic traditional round gauges while also supplying digital readouts of the parameters. EICAS improves situational awareness by allowing the aircrew to view complex information in a graphical format and also by alerting the crew to unusual or hazardous situations. For example, if an engine begins to lose oil pressure,

2706-407: The captain and first officer's instruments to an instrument comparator. The comparator warns of excessive differences between the captain and first officer displays. Even a fault as far downstream as a jam in, say, the roll mechanism of an ADI triggers a comparator warning. The instrument comparator thus provides both comparator monitoring and display monitoring. With EFIS, the comparator function

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2772-429: The color or shape of the display or by providing audio alerts. The names Electronic Attitude Director Indicator and Electronic Horizontal Situation Indicator are used by some manufacturers. However, a simulated ADI is only the centerpiece of the PFD. Additional information is both superimposed on and arranged around this graphic. Multi-function displays can render a separate navigation display unnecessary. Another option

2838-403: The desired gun position back to the gun location. Early systems just moved indicator dials, but with the advent of the amplidyne , as well as motor-driven high-powered hydraulic servos , the fire control system could directly control the positions of heavy guns. Smaller synchros are still used to remotely drive indicator gauges and as rotary position sensors for aircraft control surfaces, where

2904-468: The electro-mechanical flight instruments in the space shuttles with glass cockpit components. The articles mentioned how glass cockpit components had the added benefit of being a few hundred pounds lighter than the original flight instruments and support systems used in the Space Shuttles. The Space Shuttle Atlantis was the first orbiter to be retrofitted with a glass cockpit in 2000 with

2970-471: The glide radius of the aircraft, given current location over terrain, winds, and aircraft speed and altitude. MFDs can also display information about aircraft systems, such as fuel and electrical systems (see EICAS, below). As with the PFD, the MFD can change the color or shape of the data to alert the aircrew to hazardous situations. EICAS (Engine Indications and Crew Alerting System) displays information about

3036-413: The graphics generator and display driver produce the inputs to the display units. Like personal computers, flight instrument systems need power-on-self-test facilities and continuous self-monitoring. Flight instrument systems, however, need additional monitoring capabilities: Traditional (electromechanical) displays are equipped with synchro mechanisms that transmit the pitch, roll, and heading shown on

3102-457: The growing number of cockpit elements were competing for cockpit space and pilot attention. As a result, NASA conducted research on displays that could process the raw aircraft system and flight data into an integrated, easily understood picture of the flight situation, culminating in a series of flights demonstrating a full glass cockpit system. The success of the NASA-led glass cockpit work

3168-492: The internal, samples the output from its own symbol generator to the display unit and computes, for example, what roll attitude should produce that indication. This computed roll attitude is then compared with the roll attitude input to the symbol generator from the INS or AHRS . Any difference has probably been introduced by faulty processing, and triggers a warning on the relevant display. The external monitoring channel carries out

3234-551: The launch of STS-101 . Columbia was the second orbiter with a glass cockpit on STS-109 in 2002, followed by Discovery in 2005 with STS-114 , and Endeavour in 2007 with STS-118 . NASA's Orion spacecraft will use glass cockpits derived from Boeing 787 Dreamliner . As aircraft operation depends on glass cockpit systems, flight crews must be trained to deal with failures. The Airbus A320 family has seen fifty incidents where several flight displays were lost. On 25 January 2008, United Airlines Flight 731 experienced

3300-407: The life and death importance of appropriate training on these complex systems... While the technological innovations and flight management tools that glass cockpit-equipped airplanes bring to the general aviation community should reduce the number of fatal accidents, we have not—unfortunately—seen that happen. Synchro A synchro (also known as selsyn and by other brand names) is, in effect,

3366-718: The mains excitation voltage sources must match in voltage and phase. The safest approach is to bus the five or six lines from transmitters and receivers at a common point. Different makes of selsyns, used in interlock systems, have different output voltages. In all cases, three-phase systems will handle more power and operate a bit more smoothly. The excitation is often 208/240-V 3-phase mains power. Many synchros operate on 30 to 60   V AC also. Synchro transmitters are as described, but 50- and 60-Hz synchro receivers require rotary dampers to keep their shafts from oscillating when not loaded (as with dials) or lightly loaded in high-accuracy applications. A different type of receiver, called

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3432-636: The most pertinent information. They are also popular with airline companies as they usually eliminate the need for a flight engineer , saving costs. In recent years the technology has also become widely available in small aircraft. As aircraft displays have modernized, the sensors that feed them have modernized as well. Traditional gyroscopic flight instruments have been replaced by electronic attitude and heading reference systems (AHRS) and air data computers (ADCs), improving reliability and reducing cost and maintenance. GPS receivers are usually integrated into glass cockpits. Early glass cockpits, found in

3498-631: The needs of the owners of these aircraft. Today, smartphones and tablets use mini-applications, or "apps", to remotely control complex devices, by WiFi radio interface. They demonstrate how the "glass cockpit" idea is being applied to consumer devices. Applications include toy-grade UAVs which use the display and touch screen of a tablet or smartphone to employ every aspect of the "glass cockpit" for instrument display, and fly-by-wire for aircraft control. The glass cockpit idea made news in 1980s trade magazines, like Aviation Week & Space Technology , when NASA announced that it would be replacing most of

3564-415: The on-board electrical generator driven by the engines). Single phase units have five wires: two for an exciter winding (typically line voltage) and three for the output/input. These three are bussed to the other synchros in the system, and provide the power and information to align the shafts of all the receivers. Synchro transmitters and receivers must be powered by the same branch circuit, so to speak;

3630-557: The other's rotation when connected properly. One transmitter can turn several receivers; if torque is a factor, the transmitter must be physically larger to source the additional current. In a motion picture interlock system, a large motor-driven distributor can drive as many as 20 machines, sound dubbers, footage counters, and projectors. Synchros designed for terrestrial use tend to be driven at 50 or 60 hertz (the mains frequency in most countries), while those for marine or aeronautical use tend to operate at 400 hertz (the frequency of

3696-416: The pilot brings the pitch to an acceptable level. This helps the pilot focus on the most important tasks. Traditional instruments have long used color, but lack the ability to change a color to indicate some change in condition. The electronic display technology of EFIS has no such restriction and uses color widely. For example, as an aircraft approaches the glide slope, a blue caption can indicate glide slope

3762-418: The pilot doesn't need it. Under normal conditions, an EFIS might not display some indications, e.g., engine vibration. Only when some parameter exceeds its limits does the system display the reading. In similar fashion, EFIS is programmed to show the glideslope scale and pointer only during an ILS approach. In the case of an input failure, an electromechanical instrument adds yet another indicator—typically,

3828-415: The pilot selects the desired level-off altitude on a control unit. The EFIS repeats this selected altitude on the PFD, and by comparing it with the actual altitude (from the air data computer) generates an altitude error display. This same altitude selection is used by the automatic flight control system to level off, and by the altitude alerting system to provide appropriate warnings. The EFIS visual display

3894-400: The radio altimeter's maximum, results in a warning. At various stages of a flight, a pilot needs different combinations of data. Ideally, the avionics only show the data in use—but an electromechanical instrument must be in view all the time. To improve display clarity, ADIs and HSIs use intricate mechanisms to remove superfluous indications temporarily—e.g., removing the glide slope scale when

3960-418: The reliability of these rugged devices is needed. Digital devices such as the rotary encoder have replaced synchros in most other applications. Selsyn motors were widely used in motion picture equipment to synchronize movie cameras and sound recording equipment, before the advent of crystal oscillators and microelectronics . Large synchros were used on naval warships, such as destroyers, to operate

4026-537: The same check on the symbol generator on the other side of the flight deck: the Captain's symbol generator checks the First Officer's, the First Officer's checks the Captain's. Whichever symbol generator detects a fault, puts up a warning on its own display. The external monitoring channel also checks sensor inputs (to the symbol generator) for reasonableness. A spurious input, such as a radio height greater than

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4092-445: The shafts. Differential synchros are another category. They have three-lead rotors and stators like the stator described above, and can be transmitters or receivers. A differential transmitter is connected between a synchro transmitter and a receiver, and its shaft's position adds to (or subtracts from, depending upon definition) the angle defined by the transmitter. A differential receiver is connected between two transmitters, and shows

4158-412: The steering gear from the wheel on the bridge. There are two types of synchro systems: torque systems and control systems. In a torque system, a synchro will provide a low-power mechanical output sufficient to position an indicating device, actuate a sensitive switch or move light loads without power amplification. In simpler terms, a torque synchro system is a system in which the transmitted signal does

4224-466: The sum (or difference, again as defined) between the shaft positions of the two transmitters. There are synchro-like devices called transolvers, somewhat like differential synchros, but with three-lead rotors and four-lead stators. A resolver is similar to a synchro, but has a stator with four leads, the windings being 90 degrees apart physically instead of 120 degrees. Its rotor might be synchro-like, or have two sets of windings 90 degrees apart. Although

4290-427: The usable work. In such a system, accuracy on the order of one degree is attainable. In a control system, a synchro will provide a voltage for conversion to torque through an amplifier and a servomotor . Control type synchros are used in applications that require large torques or high accuracy such as follow-up links and error detectors in servo, automatic control systems (such as an autopilot system). In simpler terms,

4356-437: Was not at a level where sufficiently light and powerful electronics were available. The increasing complexity of transport aircraft, the advent of digital systems and the growing air traffic congestion around airports began to change that. The Boeing 2707 was one of the earliest commercial aircraft designed with a glass cockpit. Most cockpit instruments were still analog, but cathode-ray tube (CRT) displays were to be used for

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