More Than Just Fancy Flying
How Human Factors Engineering Can Improve Cockpit Design
Human Factors Engineers are all about making the interactions between systems and their users easier, safer, and ultimately more efficient. HFEs are all about design and functionality — they are constantly looking for ways to improve old systems or build brand-new ones to replace outdated standards! One area Human Factors Engineers are heavily involved with is cockpit design…though, this is often easier said than done.
Military helicopters are notorious for having very tight crew stations packed with a ridiculous amount of avionics and mission equipment. Traditional military helicopter platforms, such as the UH-60M Blackhawk, are designed with mission execution in mind and leave a lot to be desired in terms of crew station and pilot vehicle interface design.
As technology advances and parts obsolescence becomes an issue, the crew stations can quickly become over-populated with control panels and disparate display elements from newly integrated systems that lack any cohesive design paradigms or consistency from a system perspective. So, what does a Human Factors Engineer do in a situation like this?
Human Factors Engineers are the glue that keeps the aircraft crew stations functioning safely and efficiently. Though, again, there are sometimes many factors working against them when trying to update older systems with brand new subsystems.
If you’re ever in this situation, or similar ones, here are some tips and tricks for applying human factors principles to crew station design.
1) Conduct a task analysis on the new equipment you are integrating
It’s critical to keep the pilot and the mission in mind when integrating new systems into a cockpit. Performing a task analysis before designing is essential to understand the new component’s functions as well as how those functions work with existing systems on the aircraft.
In some cases, the component is a standalone system and doesn’t have any dependencies on any other aircraft systems. In most cases, the new system adds to existing functionality, and you will need to be consistent in your approach to integration.
Understanding the “what” and “why” rationale for a component will help you determine the “how” for integrating its functionality into the system. Below is an example of how you can set up your task analysis for aviation related functions.
2) Consult the almighty standards!
Military and civil aviation governing bodies reference tons of standards and specifications for almost all elements of aircraft design, including standard display symbology, personnel accommodation requirements, lighting requirements, and even acceptable color palettes!
Customers may not always reference standards or specifications that outline what you need to design to, or worse… they reference ALL the standards, and you are left dealing with conflicting design requirements. Regardless, there’s a wealth of knowledge and information that you can gather from existing standards.
However, feel free to tailor the application of these standards and design recommendations to fit the needs of your platform or customer. Some examples of go-to standards would be:
· MIL-STD-1472, Department of Defense Design Criteria Standard: Human Engineering
· MIL-STD-2525, Department of Defense Design Interface Standard: Common Warfighting Symbology
· SAE ARP, Society of Automotive Engineers (SAE) Aerospace Recommended Practice (ARP) 4102 Flight Deck Panels, Controls, and Displays
3) Stay in the “Zone”!
When adding new control panels to a console, you need to prioritize the most important controls to the most reachable locations on a console. Therefore, you need to know your zones and then design your console as appropriate for those zones. The Military Standard: Aircrew Station Geometry for Military Aircraft (MIL-STD-1333B) helps illustrate these Reach Zones for you in detail, but here is a high-level overview of the zone definitions:
Zone 1 Reach: This is defined as fully restrained (harness locked) and equipped (“full combat load”) without stretching arm or shoulder muscles — Imagine you are pulling G’s and you are pressed up against your seat… what controls will you need to access when in this position? You guessed it! Emergency controls! Preserve emergency operation controls for Zone 1 Reach.
Zone 2 Reach: This is defined as harness locked, seated upright with maximum extension from the shoulders — Imagine a toddler in a car seat stretching to reach their brother’s ice cream cone. You have some reach in you, but you are still very restricted. “Essential” controls should be located within Zone 2 Reach. And in this case, essential controls are dictated by the mission profile of the aircraft. So, if you are working on a Search and Rescue aircraft, your essential controls would be searchlight controls, rescue hoist controls, or electro-optical/infrared sensor controls. If you are on an attack or assault aircraft, weapons controls and safety interlocks need to be located within Zone 2 Reach.
Zone 3 Reach: This is defined as harness unlocked, giving the operator the ability to freely move their shoulders and torso to the maximum limit permitted by the restraint system or their own physical limitations. Non-critical or non-essential controls should be located within Zone 3 Reach. That’s where we put those trusty “set it and forget it” controls. It keeps those controls still within reach if and when they are needed but prioritizes Zone 1 and 2 Reach access for mission-essential or safety-of-flight critical controls.
4) Consistency is key!
When designing something from scratch, applying ALL the human factors principles is a Human Factors Engineer’s dream…unfortunately, that’s never the case when integrating into existing platforms. Design paradigms, whether you agree with them or not, already exist. Sometimes breaking those paradigms is warranted.
That said, most of the time, it can be confusing and introduce more cognitive workload demands on the operator to break those design paradigms just for the sake of breaking them. You have to strike a balance between integrating new technology or components into your platform and keeping consistent with the existing architecture and nomenclature. A few things to consider:
- Avoid using terminology/nomenclature that conflicts with the current design
- Try to ensure consistent color and symbology usage throughout the system (e.g., if the system uses yellow or amber to indicate a degraded state or caution, do not use it to add a “pop of color” to your graphics)
- Ensure warnings, cautions, and advisories (WCAs) for new systems follow the existing system’s presentation and prioritization scheme
5) Testing, Testing, 1,2,3!!
As with all things human factors-related, vigorous and thorough testing is a necessity to ensure seamless integration of a component into an existing platform. Do not just test the component in a silo. Integration testing requires testing all systems that are impacted by the change in a contextually relevant manner.
This could be done in systems integration labs, full motion-based simulators, or aircraft ground/flight testing environments. The best thing to do is create a test card that allows the operator to perform normal flight functions (e.g., aviate, navigate, and communicate) in conjunction with mission-specific functions that include the new equipment/component you are integrating.
Workload data (psychomotor, sensory, and cognitive) and usability data should be collected during these test events. Feedback from the workload and usability testing should be utilized to identify issues with the integration and prioritize system refinements as necessary.
Conclusion
Human Factors Engineers work tirelessly to improve the design of old systems for better interactions — leading to improved efficiency and safety.
There are many principles that HFEs can leverage to accomplish this incredibly important task — though the tips provided here don’t scratch on every aspect of human factor engineering’s role in system integration, it should give you a really great starting point to ensure user-centered design and personnel accommodation are considered when you start to re-design your own cockpits!
For more on Human Factors and Design, see this article on Medium.
References
Department of Defense. (2019). Department of Defense Design Criteria Standard: Human Engineering
(MIL-STD-1472H). U.S. Department of Defense. http://everyspec.com/MIL-STD/MIL-STD-1400-1499/MIL-STD-1472H_57041/
Department of Defense. (2014). Department of Defense Interface Standard: Joint Military Symbology
(MIL-STD-2525D). Department of Defense. http://everyspec.com/MIL-STD/MIL-STD-2000-2999/MIL-STD-2525D_50933/
Society of Automotive Engineers. (2007). Society of Automotive Engineers Aerospace Recommended
Practice Flight Deck Panels, Controls, and Displays (ARP4102). Society of Automotive Engineers. https://www.sae.org/standards/content/arp4102/
