US National Transportation Safety Board (NTSB) chief Jennifer Homendy called recent US-media claims that deliberate pilot action caused the Air India flight AI 171 crash “premature and speculative”. “India’s Aircraft Accident Investigation Bureau (AAIB) just released its preliminary report. Investigations of this magnitude take time,” she said.Since last week’s preliminary report stated that the Boeing-787 crashed after its fuel control switches “transitioned from ‘RUN’ to ‘CUTOFF’” moments after take-off, there has been much speculation about the reason behind this. Suggestions of deliberate pilot action come from the fact that these switches are designed to only be intentionally moved, and are foolproof using a bracket and stop lock mechanisms.In fact, almost everything inside an aircraft cockpit — from the placement of control interfaces and instruments to the design of the pilots’ seating — is well thought of with the ultimate aim of improving efficiency, effectiveness, and safety. This is called cockpit ergonomics.‘Science of work’Ergonomics, also referred to as “human factors,” is defined by the International Ergonomics Association (IEA) as “the scientific discipline concerned with the understanding of interactions among humans and other elements of a system and the profession that applies theory, principles, data, and methods to design in order to optimise human well-being and overall system performance.”The word “ergonomics” comes from the Greek ergon (work) and nomos (laws), which scholars translate to “the science of work”. The point of this discipline is to optimise the interaction between humans and systems. Ergonomics in cockpit design specifically focuses on creating a workspace for pilots that minimises their physical and cognitive workload, which in turn makes an aircraft easier and safer to fly.Ergonomics in aviationThe early days of aircraft development did not centre ergonomic considerations. While the importance of human factors was recognised by many — the United States’ National Advisory Committee for Aeronautics in 1921 held that instruments aboard aircraft must be made for “the easiest possible reading and manipulation” — this did not necessarily translate to conscious design decisions.In the archives | A Story of FlightIn ‘Investigations of aviation accidents and lessons to be drawn from them’ (1924), pioneering French aviator Félix Devaluez noted “pilot error” was the second most prevalent cause of plane crashes but attributed this to pilots’ “error of judgment or lack of reasoning ability”. He recommended improvement of training regimens and rigorous technical examinations to address the issue.Story continues below this adIt was near the outbreak of World War II that newly established aviation psychology units in both Britain and the US became “the first to deal with the problem of pilot error as a design problem instead of a personnel or training problem,” Prof Steven J Landry wrote in ‘Human Factors and Ergonomics in Aviation’ published in the Handbook of Human Factors and Ergonomics (2021).In 1951, US Air Force Lieutenant Colonel Paul Fitts edited a seminal US-government commissioned report that outlined key human factor challenges in aviation.Fitts wrote that “machines should be made for men; not men forcibly adapted to machines” and that the “disregard of physiological and sensory handicaps… [and] human limitations… led to the the production of mechanical monstrosities which tax the capabilities of human operators and hinder the integration of man and machine…” (‘Human Engineering for an Effective Air Navigation and Traffic-Control System’, 1951).This got the ball rolling vis-à-vis ergonomics in aviation: major developments, from the creation of modern air traffic control to subsequent revolutions in cockpit design can be traced to Fitts’ report, and his groundbreaking work on ergonomics.Story continues below this adCockpit ergonomics: a primerA few key aspects of cockpit ergonomics are as follows.Layout of instrumentation: It is vital that pilots can quickly and accurately access vital information even in high-stress situations. The cockpit of a Boeing 787-8. Every switch and control panel in the cockpit is designed with ergonomic considerations in mind. Wikimedia CommonsFor instance, beginning in the 1970s, the availability of cathode-ray and computing technology enabled the replacement of single-sensor, single instrument (SSSI) displays with electronic displays. Cockpits went digital: values were easier to read than on analogue instrumentation, more information could be packed in less unit space, and linked to computers, electronic displays could present information in novel, ergonomic ways such that the pilot focuses only on what matters the most at any given situation. The modern Electronic Flight Instrument System (EFIS) comprises a primary flight display (PFD), a multi-function display (MFD), and engine indicating and crew alerting system (EICAS) display.Human machine interface (HMI): HMI is a feature of a certain machine through which humans directly engage and interact with it. Inside a cockpit, this would refer to the design of specific knobs, touchscreens, buttons, and other control interfaces. HMI considerations in a cockpit are essentially geared towards making it simpler to operate any system — controls must be easy, intuitive to reach and use — while preventing accidental operation.Story continues below this adKomalFor instance, the design of the Boeing 787’s fuel control knob includes brackets (raised surfaces) which prevent them from being touched accidentally, and the knob itself has a stop-lock mechanism requiring deliberate action to change the switch’s position. Even so, in the light of the Ahmedabad crash, some experts have suggested moving the switch from the busy thrust console, and introducing a cap to further improve safety.Pilot seating & visibility: Ergonomically-designed seating helps prevent discomfort and fatigue for pilots by ensuring they maintain optimal posture even while also having full control and situational awareness. Pilots should have as clear a view of their surroundings, both within and outside the aircraft, without having to unduly strain themselves.Over the years, the introduction of heads-up displays (a transparent display that shows data in a pilot’s line of sight), and customisable seating have been major developments in this regard. The most cutting-edge aircraft seats also come with sensors which monitor pilots’ vitals, and can send alerts about potential health issues & fatigue.Moreover, there have been numerous developments towards improving the visibility of displays and control surfaces under all lighting conditions, including the introduction of backlighting and anti-glare features.Story continues below this adApart from this, ergonomic considerations go into the design of alarm and warning systems (including the choice of audio signals), communications systems within and outside the aircraft, and standard protocols for coordination between pilot and co-pilot, which have evolved over the years to further define roles while also increasing redundancies. For instance, the protocol for cutting fuel off from a particular engine requires both pilots to concur and confirm before the action is carried out.The automation trendDevelopment in cockpit ergonomics is a “cat and mouse game”: past challenges drive improvement and innovation which throw up a different set of problems which then have to be dealt with. Catastrophic accidents are often crucial drivers of change.The most important trend to have emerged in cockpit ergonomics — and aviation ergonomics, in general — over the past century is the gradual shift towards automation.The earliest “autopilot” system, essentially a gyroscopic stabiliser that kept the aircraft stable without pilots touching the controls, was conceptualised for aircraft as early as the 1910s. As flights became longer, and the aircraft grew in complexity, more and more functions began to be automated, especially with the introduction of modern computers aboard aircraft.Story continues below this adThe central thrust towards automation is to make the pilot’s life easier, and reduce human-error. “By performing mundane and repetitive tasks, automation has reduced crew workloads and attentional demands, allowing them to focus on tasks that are of higher priority,” Martin Brennan and Wen-Chin Li wrote in ‘The Design Principles of Flight Deck Automation’ published in 2017 in the Journal of Air Safety and Management. Today, all kinds of tasks aboard a cockpit are automated, and in normal circumstances, the plane pilots itself for most of the duration of a flight.But this automation also creates a certain dependence, which in the long run, has limited pilots’ exposure to manual flying and reduced their ability to “build and retain the competencies necessary to take control during emergent events,” Brennan and Li wrote.Moreover, as Boeing’s faulty Maneuvering Characteristics Augmentation System (MCAS), designed to improve an aircraft’s handling in certain situations showed, “bad” automation can have deadly consequences. The flawed system was responsible for two crashes in 2018 and 2019 that claimed 346 lives in total.Also Read | Crashes, blowout, leadership shake-up: What explains the Boeing MAX’s issues?The debate around automation is perhaps best exemplified in the fundamental differences between the Boeing and Airbus cockpits.Story continues below this adAirbus, which is far more automation-forward, in the 1980s introduced fly-by-wire (FBW) systems allowing for electronic handling of its aircraft with pilot inputs entered through a sidestick. The A320 flight deck was considered to be a “revolution” in cockpit design, which significantly simplified pilot operations, and reduced fatigue and workload.While Boeing has introduced FBW in its modern aircraft, it still allows for far more manual “freedom” for pilots. Notably, Boeing aircraft have retained the age-old yoke, which sits between the pilot’s legs. Its philosophy, the American aviation giant claims, keeps the pilot central to all critical decisions, allows greater control during emergencies, or in case of computers failing to do their job.