Electronic Flight Instrument System

Electronic Flight Instrument System
Naddsy · CC BY 2.0 · source
Name	Electronic Flight Instrument System
Caption	Glass cockpit display in a modern airliner
Type	Avionics system
Introduced	1980s
Manufacturer	Honeywell International Inc., Collins Aerospace, Thales Group, Garmin Ltd.

Electronic Flight Instrument System

An Electronic Flight Instrument System provides pilots with primary flight, navigation, and system information on integrated electronic displays in modern Boeing and Airbus airframes as well as general aviation platforms from Cessna and Piper Aircraft. It replaces legacy electromechanical attitude indicators and altimeters with glass displays that aggregate data from Inertial navigation systems, Global Positioning System, and aircraft flight management systems. Certified for use in commercial Federal Aviation Administration and European Union Aviation Safety Agency operations, these systems are central to modern avionics architecture, operational procedures, and regulatory compliance.

Overview

An Electronic Flight Instrument System consolidates primary flight instruments—attitude indicator, heading indicator, altimeter, airspeed indicator—and navigation charts into multifunction displays used in Boeing 737, Airbus A320, Embraer regional jets, and corporate Gulfstream and Bombardier business jets. Typical installations incorporate displays from suppliers such as Garmin, Rockwell Collins, Honeywell, and Thales, and interface with sensors including AHRS units, IRS, and VOR receivers. Integration with Traffic Collision Avoidance System and Weather Radar enhances situational awareness for operations governed by Instrument Flight Rules and Part 121 or Part 135 regulations.

Components and Architecture

Core components include liquid crystal or LED display units manufactured by Boeing suppliers, display processors from Honeywell, and sensor inputs from Honeywell Inertial Measurement Units and GPS modules. The architecture commonly follows redundant, fault-tolerant designs derived from ARP 4754A practices and implemented in software using guidance influenced by DO-178C standards. Flight data buses such as ARINC 429, ARINC 664 (AFDX), and MIL-STD-1553 carry signals between flight management computers, autopilot servos, and EFIS displays. Backup systems may include electro-mechanical standby instruments and independent backup attitude indicators to satisfy FAA and EASA airworthiness requirements.

Display Formats and Information Presentation

EFIS displays present information via a Primary Flight Display and a Navigation Display, often configurable to show synthetic vision from suppliers like Honeywell or Garmin. Displays incorporate sky/ground cues, slip-skid indicators, vertical speed trends, and navigation waypoints derived from Flight Management System databases tied to Jeppesen and LIDO charting. Pilots can overlay TCAS traffic, NEXRAD weather, and TAWS terrain alerts. Human–machine interfaces are influenced by research from institutions such as NASA and MIT into symbology, color coding, and declutter logic to reduce workload during approach and landing and airborne icing encounters.

Functionality and Integration with Avionics

EFIS integrates with autopilot and autothrottle systems in aircraft like Boeing 787 and Airbus A350 to execute LNAV/VNAV and coupled approaches using ILS and RNAV guidance. Data exchange with air data computers and engine monitoring systems permits display of engine parameters and alerting using formats standardized by ARP 4754A and DO-160. Integration enables features such as required navigation performance (RNP) procedures endorsed by ICAO and FAA performance-based navigation initiatives. Maintenance and prognostics are enabled through health monitoring systems compatible with ARINC 429 and airline flight operations quality assurance programs.

Certification, Standards, and Safety Considerations

Certification follows processes mandated by Federal Aviation Administration and European Union Aviation Safety Agency and relies on RTCA standards such as RTCA DO-178C for software and RTCA DO-254 for hardware. Electromagnetic compatibility is tested under RTCA DO-160 conditions and equipment qualification often references ARP 4754A for system development assurance. Safety assessments employ system safety techniques, including hazard analyses and Fault Tree Analysis, and consider human factors guidance from ICAO Annexes and FAA advisory circulars to mitigate mode confusion, display failure modes, and software common-cause failures.

Operational Use and Human Factors

Airline training departments at Delta Air Lines, American Airlines, and United Airlines incorporate EFIS procedures into type rating syllabi, simulator sessions at CAE Inc. and FlightSafety International, and checkride standards administered by FAA and EASA examiners. Human factors research from NASA Ames Research Center, MIT Human Factors, and Loughborough University informs display ergonomics, alerting thresholds, and glance behavior to reduce loss-of-control and controlled flight into terrain risks. Crew resource management practices and standard operating procedures from ICAO and airline operations manuals standardize scan patterns and failure responses.

History and Technological Development

Early digital displays appeared in military aircraft such as the F-16 Fighting Falcon and civil developments accelerated with Boeing 747-400 and Airbus A320 programs. Advances in glass cockpit technology were driven by companies like Garmin and Rockwell Collins and by research at NASA Langley Research Center into synthetic vision and enhanced vision systems. The adoption of EFIS in general aviation followed certification milestones for models like the Cirrus SR22 and the Cessna 172 avionics retrofits. Ongoing innovation includes integration with satellite-based augmentation systems like WAAS and EGNOS, and continued evolution toward integrated modular avionics advocated by ARP 4754A and implemented in platforms such as the Airbus A380 and Boeing 787.

Category:Aircraft instruments