Airbus vs Boeing Design Philosophy

Automation Philosophies

Much of the similarity, both in terms of anthropometric design and automation, is mandated by the certification requirements defined by EASA and FAA in CS/FAR-25. This dictates much of what must be visible to the flight crew, as well as their respective distance or angle from the ocular reference point for some instruments (EASA 2020).

The significant visual difference between the design of the two cockpits has been observed to be the inclusion of a Control Yoke on the Boeing aircraft, as opposed to the Side Stick found on the Airbus. Behind these two design differences, there is a fundamental difference in the automation philosophy between the two manufacturers. Both manufacturers have previously outlined their philosophy for aircraft design and automation.

Airbus philosophy

While both manufacturers share the philosophy that pilots are ultimately responsible for the safe operation of the aircraft, Airbus said “automation should allow the operator to fully utilize the envelope safe flight…” (Spitzer, Ferrell 2015: 224) (Airbus 2017: 6). This philosophy is integrated into the automation design through Airbus Flight Control Laws. In normal and alternate law, the flight crew is able to manipulate the flight controls but is unable to perform actions that would cause the aircraft to operate outside of a predefined set of parameters (Ibsen 2009:343) .

The result is that the flight crew therefore does not have complete authority over the aircraft, as some flight envelope protections are in place to ensure that various aircraft limitations are not exceeded. These are known as “hard” limits (Spitzer, Ferrell 2015: 224). These flight envelope protections are removed in Direct Law, however this law cannot be manually selected by the crew (Ibsen 2009: 343).

Boeing philosophy

On the other hand, Boeing has stated in its design philosophy that “the pilot is the final authority for the operation of the aircraft” (Spitzer, Ferrell 2015:224). This is built into the design of its fly-by-wire aircraft by allowing the pilot complete control authority of the aircraft whether or not it results in a deviation from the normal flight envelope (Harris 2011: 379 ).

Why is there a difference in philosophy?

Airbus introduced this “hard limit” philosophy and related technology in its Airbus 320 aircraft which entered service in 1987. Since the majority of air accidents are caused by human error (Wiegmann, Shappell 2016: 10 ), one could consider that such technology was introduced on an ideological basis on the assumption that it improved flight safety. This technology has been applied consistently across all Airbus models since the A320, simplifying and streamlining crew training and aircraft maintenance, leading to cost reductions for airlines (Ibsen 2009: 347).

Boeing made the conscious decision to adopt the philosophy of total pilot authority over the aircraft by being able to override any electric flight system, when the B777 was introduced, which was the first Boeing aircraft to integrating such technology (Ibsen 2009: 347). ). With a long history of aircraft design, this has allowed a degree of commonality and continuity for pilots of Boeing aircraft (Ibsen 2009: 347). The flight crew has the flexibility to simply fly the aircraft without restriction whether they are operating old, new, small or large Boeing family airframes.

Conclusion

There are clear aesthetic similarities between the two cockpit designs which are likely due to the certification requirements clearly stated in CS/FAR-25. However, there are clear differences in the philosophy of automation, with Airbus restricting the control authority of the pilot, ensuring that the aircraft remains within a predetermined flight envelope (Harris 2011: 379). On the other hand, Boeing allows pilots operating its aircraft to have full control authority if necessary (Harris 2011: 379).

The references

Airbus. (2017) “The Airbus Cockpit Philosophy” Proceedings of the Air Operations Awareness and Safety Seminar, “Airbus Flight Operations Training and Support Standards”. Held from 19 to 21 September 2017 in Nairobi.

European Union Aviation Safety Agency (EASA), Certification Specifications and Acceptable Means of Compliance for Large Airplanes CS-25, Amendment 24. available at https://www.easa.europa.eu/sites/default/files /dfu/CS- 25%20Amendment%2024.pdf> [10 January 2020]

Harris, D. (2001) Human performance on the cockpit. London: CRC Press

Ibson, A.. (2009) “The politics of aircraft production: the emergence of two technological frameworks in the competition between Boeing and Airbus”. Technology in society 31342-349

Spitzer, C. Ferrell, U. Ferrell, T. Becker, SG. (2015) Handbook of digital avionics. London: CRC Press, Taylor & Francis Group

Wiegmann D., Shapell S. (2016) A human error approach to aircraft accident analysis. Oxford: Routledge