A glass cockpit is often thought as an aircraft cockpit equipped with large computerised screens which display flight information. This term is well known but actually refers to the introduction of Flight Management Systems (FMS) to help monitor and control the aircraft. The proper term when referring to these cockpits is "Technically Enhanced Cockpits". This technology has largely replaced the numerous analogue instruments found in military and commercial aircraft, and later, GA aircraft. (It is also good to note that the some of instruments imputing into the FMS are still the same.) The technology was developed in the late 1970s, but was not widely implemented until the 1990s. Glass cockpits usually display GPS navigation, GPWS, TCAS, weather information, and possibly sometime in the future, synthetic vision systems. However, the glass cockpit offers more than just the different display style. It offers an increase in automation ability and integration of controls, and with controls being 'fly by wire', automation systems are often far more accurate (Knight, 2007).
Safety benefits in commercial aircraft
Combining numerous instruments into several easily-read displays reduces pilot workload and fatigue, and makes it less likely that an important gauge will be missed in a scan. The main information is still based on the traditional 'T' scan to help transition between cockpit styles (analogue vs glass), however, the information is more precise and due to the computer screens can be displayed much more ergonomically. These benefits greatly increase flight safety.
The other benefit to the addition of the computer processing power is that it can also integrate more feature into the screens and also allow the display of more information, For example, the added benefit of clearly displayed GPS navigation, GPWS, TCAS, and weather information greatly increases flight safety. These systems can also be display pictorially so that the user (in this case the pilot) can get a instant mental picture rather than having to process all the information themselves.
The computers also have feedback loops and self checking programs that can alert the pilot to possible problems and sometimes the checklists to solve them. It has the ability to control certain elements of the flight so that the pilot can concentrate on more important tasks. This is especially useful during times of high stress.
While the introduction of glass cockpits has resulted in safer aviation overall, there are a few things that pilots have to be aware of. These can often be overcome with being aware of the problems and also by actively trying to maintain situational awareness.
There have been a few cases where pilots have become confused by computer generated messages. Aero Peru flight 603 was an example of this occuring. The Boeing 757 took off with its static ports covered with duct tape. As a result, the pilots recerived contradictory messages such as Rudder ratio, Mach trim, Overspeed, and Underspeed. With most of their instruments inoperable, the aircraft crashed into the Pacific ocean shortly after. While the confusion over computer-generated messages did not cause this accident, they may have distracted the pilots from flying the plane, and lead to the crash.
Due to the nature of the integration of the information, if there is a electronic fault during the flight causes the screens to blackout, this can leave the pilots in a very dangerous position because they have limited information to fly with. United Airlines flight 371 is an example of a glass cockpit blackout shortly after takeoff. The A320 lost half of its display panels, all of its radios, transponders, and TCAS. The pilots were able to land back at their departure aerodraome, but commented that they were only able to land because of the good weather conditions. If IFR conditions were present, the aircraft may have crashed.
User Interfaces (UIs)
The user interfaces (UIs) can be difficult to operate because the pilot may accidentally touch a few wrong buttons and knobs. They are too easy "to fat-finger". There are two examples of this problem; the glass cockpit has too few buttons and knobs and it has too many buttons and knobs.
In the case of a few controls, each knob or button performs multiple functions, resulting in overloading.
In the case of turbulence and emergencies, the pilot may touch and activate the wrong buttons because there are so many of them in a small area.
Problem of 'Mode Awareness'
The glass cockpit produces a problem of,'Mode Awareness', that the pilot has to ensure he / she is constantly aware of when flying in a glass cockpit. Due to the fact that the flight and engine management stystems can be set in various, 'modes', this offers the pilot the perception that the aircraft is carrying out one task when in fact its carrying out another. To prevent this problem the pilot should ensure that he / she constantly includes the aircraft's, 'mode' in his / her scan of the flying instruments constantly to ensure awareness of the aircrafts performance at all times4.
Converting to glass cockpit aircraft
Flying a glass cockpit aircraft requires a different cognitive style of thinking. As a result, converting from a traditional commercial aircraft with hundreds of indiviudual instruments, to a glass cockpit jet with just a few displays requires more than just learning where to look. Older pilots, who have flown thousands of hours in traditional cockpits, usually experience some difficulty transferring to glass cockpit aircraft (Roscoe, 19921). Another intersting point is that there is potential for a pilot to become fatigued more easily when flying glass cockpit aircraft.
The ability to automation controls during flight is a huge benefit to the safety of the flight during normal situations. However, there are some very big problems that crop up.
Automation Bias: This is where the pilots use the automation, such as auto pilot, as substitute to the gathering of information. They lose situational awareness because the computers are doing it for them. It can go as far as forgetting to ever check on the system and its reliability.
Over Trust: The pilots start trusting the systems because of the fantastic job it does, and start no longer worry about the integrity of the systems and allow them to do the job. Some times they believe the computers over the other warning signs.
Over Confidence: With the ability to decrease the workload of the pilot, it means they can now complete more complex tasks during flight. However, this can create an illusion of "good piloting". The question that needs to be asked is "could you do this if the automation was off".
Reliance: The above problems often lead to reliance on the automation system. It is now being seen that pilot are losing their "flying skill" and its being replaced with supervising computer systems. The problem is some pilots can no longer fly the aircraft without the automated systems. (Skitka, 2000)
Glass cockpits in GA aircraft
The safety benefits of glass cockpit equipped GA aircraft is debatable. Having GPS navigation showing track, heading, and time to destination, range, and endurance, greatly reduces pilot workload and situational awareness, and increases safety. However, student pilots must be instructed in such a way that they do not become dependant on the computerised systems. It is still important to be able to efficiently perform manual navigation and fuel-moitoring tasks, should computerised systems fail. Another possible danger is pilots becoming emboldened by glass cockpits, and taking risks they would not usually take. Having weather and navigation information may encourage some pilots to press on into deteriorating weather. In fact, a five-year NTSB study released in 2010 outlines that GA aircraft equipped with glass cockpits have twice the fatal accident rate of aircraft equipped with traditional cockpits, although their overall accident rate was lower (Croft, 20102; NTSB, 20103).
Glass cockpits are certainly here to stay. While they have great potential to increase safety, effective pilot education is important to ensure that the fatal accident rate outlined in the NTSB study is lowered.