Considering the Evolution of Flight Deck Ergonomics and its Impact on Aircraft Certification

Sofema Online (SOL) www.sofemaonline.com takes a deep dive into the Evolution of Flight Deck Ergonomics and considers its Impact on the Aircraft Certification Process.

Introduction

Following World War II, aircraft became more complex, leading to a more crowded and confusing cockpit. The development of jet aircraft in the post-war era brought about faster and more complex machines, requiring further changes in cockpit design.

An early ergonomic advancement concerned the introduction of the "basic T" arrangement of flight instruments, positioning the airspeed indicator, artificial horizon, and altimeter in a T-shape, which increased pilots' ability to scan instruments and react more effectively.

The crash of Eastern Airlines Flight 401 in 1972, for example, led to significant changes in flight deck design.

>> The flight crew became so engrossed in troubleshooting a malfunctioning landing gear indicator that they failed to notice the autopilot had disengaged, causing the plane to slowly descend until it crashed.
>> As a result, aircraft manufacturers started to design cockpits in a way that would help pilots better monitor the status of the aeroplane and maintain situational awareness.

Ergonomics, the study of people's efficiency in their working environment, is a significant factor in aircraft cockpit design. Over time, the cockpit has evolved from a space crowded with analogue dials and gauges to a digitized environment with Heads-Up Displays (HUDs) and Electronic Flight Instrument Systems (EFIS).

Changes Introduced Post Eastern Airlines Flight 401

>> Increased emphasis on Crew Resource Management (CRM): This accident highlighted the need for effective CRM, a concept that was relatively new at the time. CRM focuses on using all available resources - information, equipment, and people - to achieve safe and efficient flight operations. Modern aircraft certification processes emphasize that crew interfaces must support effective CRM.
>> Improvement in Cockpit Warning Systems: After the accident, improvements were made to cockpit warning systems, including visual and audible alarms to alert pilots when an aircraft is descending below a safe altitude or when autopilot disengages.
>> Enhancement of Avionics and Automation Design: The accident underscored potential pitfalls in cockpit automation and prompted improvements in cockpit design to ensure that the flight crew is always aware of the aircraft's status and the status of automation systems.

o Aircraft certification processes now require manufacturers to demonstrate that flight crews can understand and manage automation.

Introduction of Cockpit Checklists: The introduction of more comprehensive checklists and standard operating procedures became crucial in managing and mitigating risks that could lead to similar accidents.

Greater Focus on Human Factors in Design and Training: Understanding how pilots interact with aircraft systems, and designing those systems to reduce the chance of error, became a greater focus in aircraft design and certification.

o This included everything from the layout of controls and displays to the use of consistent labeling and color-coding.

Introduction of Flight Simulator Training: The Eastern Air Lines crash and similar accidents led to a recognition of the importance of realistic flight simulator training, which allows crews to experience and learn from emergency situations in a safe environment.

o The certification of these flight simulators also became a significant focus for aviation authorities.

From Analog to Digital

The first major shift in flight deck design came with the transition from analogue to digital interfaces in the late 20th century.

Before this, cockpits were filled with physical dials, switches, and gauges, which could be laborious to read and required significant training and concentration from pilots.

The advent of digital technology in the 1970s and 80s led to the introduction of the glass cockpit, where mechanical dial-type instruments were replaced with multi-function displays (MFDs). This was a significant change in cockpit ergonomics and increased the amount of information available to pilots, but also required them to manage and interpret a higher volume of data.

>> The introduction of digital displays, also known as glass cockpits, revolutionized flight deck ergonomics.
>> This has led to a reevaluation of the certification processes, taking into account not just the mechanical reliability of the systems, but also the usability and interface design.

Human-Machine Interfaces (HMI):

>> There will likely be a continued push towards more intuitive interfaces, including the use of touch screens, voice control, and even eye-tracking technology.
>> HMI that adapts to the user's current workload or stress level could also become a reality.
>> The challenge for certification will be ensuring that these new interfaces don't distract pilots from their primary duties or lead to input errors.

Fly-by-Wire

Fly-by-wire technology allowed for the reduction of physical controls and the addition of safety features such as envelope protection.

>> The certification of these systems focused not only on their mechanical and electrical reliability but also on the ability of pilots to understand and control these new systems effectively.

As automation has become more integrated into the flight deck, it has brought about significant changes in ergonomics.

Modern aircraft often have auto-pilot systems, auto-throttle, and sophisticated flight management systems that can handle tasks from navigation to fuel management.

>> This has led to a decrease in workload for pilots but also introduced new challenges such as automation complacency and mode confusion.
>> Aircraft certification processes have had to adapt to ensure that automated systems are not only reliable but also designed in a way that is intuitive and does not lead to misunderstanding or misuse by pilots.

The future is Artificial Intelligence (AI)

With the introduction of artificial intelligence (AI) and machine learning in aviation, the ergonomics of flight decks are poised for another significant shift.

>> AI has the potential to further reduce pilot workload and increase safety, but also brings new challenges in terms of understanding and predicting the behaviour of these systems.

Training and Certification Considerations

The evolution of flight deck ergonomics has a significant impact on pilot training and certification.

>> Pilot training has had to evolve to ensure that pilots are familiar with the new technologies.
>> Aircraft certification has had to adapt to assess the safety, reliability, and usability of these new systems.

Next Steps

Sofema Aviation Services (www.sassofia.com) offers training to cover CS 25 System Safety Assessments – please check out the Type Certification System Safety Assessment – 5 Days Course

For additional questions or comments, don't hesitate to email us at team@sassofia.com