Electronic Flight Display System

The Electronic Flight Instrument System (EFIS) in aviation is a flight display system that presents flight data electronically rather than through electromechanical instruments in a airplane cockpit. An EFIS typically consists of one Primary Flight Display (PFD), one Multi-function Display (MFD), and an Engine Indicating and Crew Alerting System (EICAS).

^{Flight Display Systems}

The Electronic Flight Instrument System (EFIS) is a system that digitizes cockpit displays in aircraft. It replaces traditional analog instruments by providing pilots with clearer, more readable, and enriched information. EFIS enhances pilot situational awareness, ensuring safer and more efficient flight operations.

The Primary Flight Display (PFD) is one of the core components of EFIS and forms the foundation of the "glass cockpit" concept. It consolidates critical flight information such as artificial horizon, airspeed, altitude, heading, vertical speed, and yaw onto a single screen, significantly improving pilot awareness.

Data Displayed on the Primary Flight Display:

• Artificial Horizon: Shows the aircraft’s pitch and roll attitude.
• Airspeed Indicator: Displays the aircraft’s current speed.
• Altitude Indicator: Shows the aircraft’s height above sea level.
• Heading Indicator: Indicates the aircraft’s direction relative to magnetic north.
• Vertical Speed Indicator: Displays the rate of climb or descent.

The PFD can alert pilots during hazardous conditions by modifying its display. For example, it highlights critical information such as low airspeed or excessive descent rates in red to draw the pilot’s attention.

^{Primary Flight Display (Credit: Süleyman Sözkesen, Electronic Display Systems)}

The Multi-Function Display (MFD) is a screen that presents navigation and weather information from multiple sources. It supports the PFD with additional data and features a map-centric design.

Data Displayed on the Multi-Function Display:

• Navigation Information: The aircraft’s current route, position, and destination points.
• Weather Data: Radar information, storm activity, and wind conditions.
• Fuel and Electrical Systems: Fuel flow, tank levels, and electrical system status.
• Air Traffic: Distances and directions of other aircraft.
• Aircraft Glide Range: Calculated range to determine optimal landing sites during emergencies.

MFDs can be touch-sensitive or button-controlled. In some designs, navigation displays are integrated with the PFD, allowing pilots to view all data on a single screen.

^{Multi-Function Display (Credit: CMC Electronics)}

EICAS provides detailed information on aircraft engines, fuel systems, electricity systems, and other critical components. It replaces traditional analog gauges with digital readouts and graphical representations. The primary purpose of EICAS is to immediately inform pilots of system status through visual and auditory alerts.

EICAS notifies pilots of issues such as a drop in engine oil pressure or a critical drop in fuel level through alarm sounds and visual warnings.

ECAM is a system developed by Airbus with functions similar to EICAS. In addition to the information provided by EICAS, ECAM also offers troubleshooting recommendations to pilots in response to system failures.

ECAM displays step-by-step procedures on screen during emergency scenarios such as engine failure, electrical faults, or hydraulic losses, guiding pilots on the appropriate actions to take. This minimizes pilot error and enables more effective decision-making.

^{Engine Indicating and Crew Alerting System (Credit: SKYbrary.com)}

The Electronic Flight Instrument System (EFIS) is an avionics system that presents flight data to pilots through digital displays. EFIS processes data received from various sensors and flight computers to provide clear, optimized visual presentations.

EFIS gathers essential flight information from various sensors and systems onboard the aircraft. These sensors include:

• Pitot Tubes and Static Ports: Provide data on airspeed, altitude, and rate of climb or descent.
• Inertial Navigation System (INS/IRS): Determines the aircraft’s direction, acceleration, and position.
• GPS (Global Positioning System): Delivers precise position data and integrates with the navigation system.
• Air Data Computer (ADC): Processes parameters such as airspeed, altitude, and temperature.
• Flight Management System (FMS): Calculates route, fuel management, and automatic flight controls.
• Engine and System Monitoring Sensors: Collect data on engine temperature, fuel consumption, hydraulic pressure, and other aircraft systems.

Raw data collected from sensors is analyzed and organized by the central processing unit known as the Avionics Data Processing Unit. During this process:

• Data from sensors is verified for accuracy.
• Cross-checking between related systems minimizes errors.
• Abnormal conditions or system faults are detected and alerts are generated.
• Data is formatted for clear visual and graphical presentation.

EFIS uses LCD or LED displays to present flight information to pilots in an understandable format. The main displays are:

• Primary Flight Display (PFD): Contains critical flight data such as artificial horizon, airspeed, altitude, turn rate, and weather information.
• Multi-Function Display (MFD): Displays comprehensive data including maps, weather radar, and engine performance metrics.
• Engine Indicating and Crew Alerting System (EICAS/ECAM): Provides information on engine status, fuel consumption, flight control systems, and fault warnings.

EFIS does more than display data; it enhances situational awareness by providing alerts and recommendations to pilots. For example:

• If fuel pressure drops, the EICAS/ECAM system issues an alert and suggests corrective actions.
• If an abnormal air current is detected, relevant indicators on the PFD are highlighted to enable rapid pilot response.
• If a navigation error is detected, the MFD suggests alternative routes.

EFIS operates in conjunction with aircraft automation systems, sharing data with autopilot, automated landing systems, and air traffic management systems. For example:

• Flight Management System (FMS): Assists the autopilot in maintaining the aircraft on its planned route.
• Traffic Alert and Collision Avoidance System (TCAS): Displays the positions of other aircraft and potential collision risks on EFIS screens.
• Weather Radar Systems: Provide pilots with up-to-date meteorological data and warnings about hazardous weather conditions.

EFIS presents flight data in a visually enriched format, enabling pilots to rapidly assess critical aircraft information.

• Highlighting of critical information: For example, if the aircraft experiences a sudden altitude loss, this condition is prominently displayed in red on the instrument panel.
• Integrated mapping systems: Pilots can view navigation maps and air traffic data on the same screen, reducing the need for external systems to analyze complex data.
• Artificial Horizon: Provides clear flight orientation even under low-visibility conditions.

By organizing information effectively, EFIS prevents pilots from being overwhelmed by unnecessary data.

• Prioritization of information: During critical situations, only the most important indicators are highlighted, minimizing distractions.
• Automatic fault detection and recommendations: EICAS or ECAM systems suggest corrective actions during failures or critical events. For instance, in the event of an engine failure, recommended procedures appear on screen.
• Reduced physical effort: While pilots using traditional electromechanical instruments must constantly move between panels to gather information, EFIS consolidates all data on a single screen, optimizing eye movement.

EFIS offers several features designed to improve flight safety:

• Real-time system monitoring: Engines, fuel, hydraulic, and electrical systems are continuously monitored with early warnings for potential failures.
• Air traffic alerts: EFIS integrates with the Traffic Alert and Collision Avoidance System (TCAS) to warn of potential collision risks.
• Automatic weather updates: EFIS automatically analyzes changing weather conditions during flight and alerts pilots to hazardous weather events.

• Simplicity and Ease of Understanding: Training pilots accustomed to traditional instruments is lengthy and complex. Thanks to EFIS’s graphical interface, new-generation pilots can grasp flight information more quickly.
• Compatibility with simulators: Modern flight simulators replicate EFIS systems exactly, enabling pilots to receive realistic training.

• Lighter and more compact system: Traditional electromechanical instruments occupy more space and are heavier. EFIS reduces this weight through digital displays, contributing to fuel savings.
• Lower maintenance requirements: Digital systems are less prone to failure than electromechanical instruments, reducing aircraft maintenance time and costs.
• Energy efficiency: Lower-power display technologies reduce the overall energy consumption of flight systems.

• Display layouts tailored to mission profiles: Custom EFIS configurations can be developed for military aircraft, passenger airliners, or business jets.
• Pilot-specific customization: Display colors, symbols, and screen layouts can be adjusted according to individual pilot preferences.
• Interface updates: Software updates allow EFIS displays to be easily adapted to new flight requirements.