12 minute read
Understanding BizAv Avionics: Interactive
Within the field of cockpit avionics, a core category of instruments and functionality covers those that are interactive. Ken Elliott takes a closer look.
The cockpit is the location where the interactive flight workload is undertaken. That workload involves attentive activity from inside and outside the aircraft, including other aircraft and air traffic control (ATC).
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Nevertheless, when it comes to purchasing aircraft, whether it’s new or pre-owned, limited attention is paid to the cockpit compared to the aircraft’s performance and the suitability of its cabin.
In this month’s article, we deviate from aircraft equipage and concentrate on the interaction of pilots with the aircraft’s equipment and tools available for manipulation, monitoring and informing. As we move toward touchscreen displays and modular system computing, there will be a reduction in remote equipment.
In the far future ‘points of interface’ will be connected via a triplicated redundancy network to the ‘aviation cloud’. Most functions conducted onboard today, will be handled offboard by the aviation cloud in the future.
For now, however, we rely on remote equipment, installed on board the aircraft. Such equipment is termed Line Replacement Units (LRUs), or Modular Avionics, and is installed as electronic cards – all of which are controlled by pilot using dedicated cockpit control devices.
LRUs are found all over the aircraft, hidden under the floor, in dedicated equipment bays, behind cabin trim, in the tail, attached to engines, and in the nose, and each has a purpose. It can communicate, navigate, surveil, convert, sense, collect, push-pull data inside, and move information on and off the aircraft.
In the specific case of airframe and engine flight controls, these LRUs provide an added ‘digital to
analogue’ capability, shifting and capturing the status of the aircraft’s moving parts.
All this dynamic action must be monitored and controlled by the pilot(s).
The complexity alone is so involved that it deserves its own ‘Interactive’ category within avionics. The movement of data across the aircraft systems, to and from ATC and between other aircraft, has a tremendous impact on pilot workload if it is not handled and managed correctly. Data that is sorted, integrated, and prioritized at super speeds and bandwidth can handle the system demands, while human factors is the guidance managing pilot interaction.
‘Interactive’, as a category, slots in with the other four primary avionics categories that include Communication, Navigation, Surveillance, and Cabin.
Cockpit Evolution
Traditionally, pilots responded to information presented by rows of instruments, dials and lights, using switches, control units, headsets, and flight controls for interaction. Later, cockpits added hybrid instrumentation, using a mix of digital and analog functionality, with some data provided on mono-color Cathode Ray Technology (CRT) displays.
Later still, color was introduced into cockpits offering an extra dimension to the pilot. Then a combination of electronic advancement, through chip innovation and display technology evolution, enabled the integration of multiple data sources into single flat-panel displays. The more recent displays add touchscreen capability.
Throughout, human factors have played an increasingly important role. First, in the priority of colors, and then in the order and layering of presentation data.
With the increase in data sorting, and display priority, across independent cockpit displays, it became apparent that to prevent confusion, a pilot decision matrix was necessary. This was made easier through decluttering.
The danger in the transition from a cluttering of instruments to interactive displays was that the clutter would move from physical instruments to electronic data, where there was still too much distraction, but now from the use of cockpit displays. As a result, equipment manufacturers have spent many hours designing cockpit displays that are more intuitive and aligned to the phase of flight underway.
Therein lies the most exciting and realistic mediumterm evolution of cockpit design. “What if we only see, and interact with information that is pertinent to the current flight profile?”
If there is a need to override an emergency or any relevant priority, then the ability to act is either permitted or automatically assumed. To this end, aircraft manufacturers collaborating with avionics manufacturers and other providers, will model, simulate, and then demonstrate complex cockpit scenarios in virtual aircraft long before the first prototype test aircraft taxis to the runway.
To make it easier to apply human factors, the avionics themselves have greater capability and functionality when it comes to the available options. Along with capability and options, displays and remote systems are self-monitored for accuracy and reliability, ensuring safety.
A significant contribution to such advancement is the introduction of Integrated Modular Avionics (IMA), replacing traditional LRUs. The concentration of data, processed in fewer modules and transferred on highspeed data buses, has transformed the look of the modern aircraft. It has also enabled greater flexibility in the selection and integration of information within the cockpit.
As with all avionics and other equipment, Size, Weight and Power with an eye on cost (SWAPc), is very important. In the cockpit this is no exception and flat panel displays are a great evolution that reduce SWAPc impacts.
FIGURE 1: Interactive as an Avionics Category
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Cockpit Display Systems
It is worth mentioning cockpit architecture and design. Several forces are at play in cockpit planning. Just two of them are the leveraging of ‘Commercial-Off-TheShelf’ (COTS) technology, and the use of open-source architecture.
The former means designers do not need to reinvent the wheel while also maintaining competitive pricing. The latter has a similar effect, because different equipment developers can share the same hardware and software development.
In fact, the whole idea of modern cockpit
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development is to standardize pilot expectation as they move across different aircraft platforms. What both aircraft and avionics manufacturers can do is to provide a different look and feel.
Seeking differentiators, equipment providers offer unique features and higher performance, while sticking to the standard basic design that all developers use. Avionics manufacturers can also garner an edge by becoming the standard platform across all aircraft models from a single provider. Examples include:
• Bombardier – Collins Aerospace • Dassault Falcon – Honeywell Aerospace • Embraer – Collins Aerospace • Gulfstream – Honeywell Aerospace • Pilatus – Honeywell Aerospace • Textron Beechcraft – Collins Aerospace
These different partnerships between aircraft and avionic OEMs allow for large variations in the look and feel, and features and performance, while sharing common baseline platform design. The partnerships apply to suites of avionics, including primary bus data that’s central to the aircraft.
There are still major sub-systems, such as third flight management systems, flight recording, and Enhanced Flight Vision Systems (EFVS) that are from other manufacturers, such as Universal Avionics, and do an amazing job of filling in the equipage gaps across many aircraft platforms.
Cockpit architecture aims to include control, display and advisories in terms of key elements to the instrument panels. These are guided by various standards, not only from engineering societies (such as SAE), but from airworthiness authorities too.
Following are some of the guidance standards used in cockpit design (with the point being, that when you next sit in a cockpit, you can appreciate the depth of engineering, ergonomic and human factors that occurred prior to its assembly):
• SAE ARP 4761 - Guidelines and Methods for
Conducting the Safety Assessment Process on Civil
Airborne Systems & Equipment. • SAE ARP 4754A – Guidelines for Development of
Civil Aircraft Systems & Equipment. • ARINC 664 - Aircraft Data Network. • ARINC 661 - Cockpit Display Systems. • AC 20-170 – Integrated Modular Avionics
Development, Verification, Integration, and
Approval Using: - TSO C153 - Integrated Modular Avionics Hardware Elements. - DO 297 - Integrated Modular Avionics (IMA) Development Guidance and Certification Considerations.
Predictive Technology in the Cockpit
Human factors in the cockpit includes situational awareness, and that varies based on the actual flight conditions. The pilot(s) must be comfortable with the real-time environment and even slightly ahead of it – hence the presence of predictive technology.
More aircraft systems are becoming predictive, moving away from reactive. Predictive aircraft know the current situation, based on sensors and connections to the outside world, through ATC, other aircraft, and the in-flight internet.
FIGURE 3: Phases of Flight
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Intelligent avionics collect and integrate data to predict what is ahead and provide that crucial lead-time for the pilot to react. In some cases, the aircraft will automatically respond, but for good reason there will be a confirmation required by the crew.
Reactive systems are not intuitive or dynamic. They are linear in design and require much more button pushing and data setting by the pilot. The pilot reacts to serial information as it is received, one byte at a time.
A great example of prediction is the latest weather radar systems that can provide doppler turbulence information at a distance, predict lightning, or depict the vertical characteristics of storms. Another is the Traffic Collision Avoidance System (TCAS) that predicts and advises corrective actions regarding the trajectory of other aircraft.
Not only are there sensors like radar that can predict, but there are advanced technologies that provide pilots with information in order to make predictive decisions, such as Enhanced Flight Vision Systems (EFVS) which, when coupled with a database-derived Synthetic Vision System (SVS), can become a Combined Vision System (CVS).
The use of multi-spectral cameras and database terrain provide a pilot with a vision that the naked eye cannot see. From that additional sensing, the pilot can predict actions with confidence, safely.
The Phases of Flight Innovation
Different systems are used during each phase of flight, and Figure 3 (above) breaks down the phases. More usual is that aircraft systems enter discrete modes for each phase – or they organize, emphasize, and display the same information in distinct formats.
What if the avionics intelligence, based on sorting and integrating data, ensures only the information the pilot needs is automatically displayed for each phase? That information can then become primary with other related data displayed as secondary.
Of course, the pilot may still search and select any information relating to any phase of flight, as an override or additional capability. System-wide artificial intelligence must also be attuned to the current or live conditions outside of the aircraft.
New aircraft cockpits and their integral systems are being designed with the phases of flight as a template to the overall flow of data. One example, currently being used by at least one manufacturer, is the use of charts linked to the active flight plan. One way to track the progressive change of charts is to select and transition using geo-referenced GPS information.
System Tools for Interaction
Table A (overleaf) lists ‘System Tool Groups’ that initiate cockpit-to-aircraft flight interaction. If you are not a pilot, the next time you climb into the cockpit, see if you can identify controls and displays that relate to these.
You will quickly realize the enormity of the flying task and develop immediate respect for air crews who must intuitively locate, manipulate, monitor and control the sub-systems within the groups.
Tools for Managing the Cockpit
To manage the cockpit, pilots are provided with multiple aids and many of those are electronic, doing away with copious documents in file folders. Modern cockpits are fitted with ports capable of USB and Ethernet, paired with power outlets, to plug in the various management tools.
However, checklists, charts, aircraft health and other information is also displayed on multifunction or secondary displays, either from systems that are internal to the aircraft, or externally via satellite or Wi-Fi.
Some management tools such as the aircraft flight manual, and its associated supplements, are required to be in paper form.
Pilots also have many support services to take advantage off, including those from ARINC, Satcom Direct, Honeywell GoDirect Flight Support Services, Jeppesen and Universal Weather & Aviation.
Advances Toward a More Intuitive Cockpit Experience
With few equipage mandates, aircraft and equipment manufacturers can focus on new and novel features to differentiate themselves, in the modern cockpit. They can also introduce features from one airframe type across to another, especially regarding Large to Midsize, and Mid-size to Light jets, and Turboprops. Here are a few examples:
• Fly-by-wire across a wider range of platforms. • Joysticks introduced by more aircraft OEMs. • Data Comm introduced to Light Jets and
Turboprops. • Autothrottles into Turboprops. • Flight Path Vector commands, leveraged from
Head-Up Displays into Head-Down systems across a wide range of platforms. • Head-Up Displays to Miz-size and Light Jets.
As well as the cross migration of technologies, there are recent improvements to existing technologies that include, for example:
• Digital Pressurization. • Digital Flight Controls (note new Dassault
Flaperon). • Head-Up Displays that combine vision systems and offer more features (note Collins Aviation
HGS6000). • Head-Up Displays with multiple sensors, cool lamp detection and wide field of view (note Universal-
Elbit Falcon Eye).
In Summary…
The main purpose of this article was to introduce Interactive as a primary category of avionics, alongside CNS and Cabin systems. Why is this so important?
Cockpits are trending toward multiple touch screen interaction for most functions, including standby instruments. That development is great for the industry but introduces new dynamics and much more behindthe-scenes activity within the cockpit.
Interaction on this new scale puts human factors to the test. Now there is so much information to sort and display, not in sequence, but multi-tasked in parallel. Human factors must ensure the cockpit remains ‘clean’, ergonomic, decluttered, efficient, with redundancy, and safety. Above all, the pilot workload should be less, not more, and pilots should never be confused.
Cockpits are moving from reactive to predictive systems that are dynamic and intuitive. Pilots work with so many variables from ‘gate to gate’. Prioritizing and deciding on what should be displayed and monitored is not easy, but linking cockpit activity to the phases of flight is one effective way to optimize the view of an aircraft’s flight. ❙
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KEN ELLIOTT
has 52 years of aviation experience focused on avionics in General and Business Aviation. Having a broad understanding after working in several countries on many aircraft types and avionics systems, he has contributed to several work groups and committees, including for NextGen, Airport Lighting, Human Factors, Unmanned Aircraft and Low Vision Technology. In retirement, he is striving to give back the knowledge gained with an eye on aviation’s future direction.
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