How are existing avionics shaping the future and sharing the aerospace with newer technologies? Ken Elliott explores…
The newer ‘Primary Enabling Electronic Technologies’ are currently being applied to smaller drones and eVTOL, while the ‘Primary Existing Advancing Electronic Technologies’ are utilized in traditional fixed-wing and rotary aircraft (as ‘Avionics’).
Eventually these technology groups will merge as one, relying on the depth of application and level of requirements to dictate its use in applications ranging from low-cost unmanned drones to high-cost transport aircraft.
Following, we’ll address each of the primary existing advancing electronic technologies to see how they are likely to impact or be impacted by the newer technologies.
Table A: Primary Existing Advancing Electronic Technologies (Avionics)
For business aircraft, having satcom has been both a luxury and an antenna real estate concern. This is changing as antenna size and overall system cost (to purchase and operate) gradually reduce.
The real difference will be felt when versions of drone satcom systems are provided as suitable for transport aircraft. This is where the pressure to miniaturize without too much compromise will come into play.
It doesn’t make sense to invest in a satellite system that costs the same price as the drone, so anticipate the inevitable price benefit being passed on too.
New satcom players have emerged. Companies such as Israel’s Getsat will cause the major avionics vendors to rethink, not just revise, their systems. Getsat has an array of nano, micro and milli Ka- or Ku-band products to feast on.
Meanwhile, traditional business aircraft equipment and service providers will continue to embrace the three satcom frequency bands available to them, in ascending frequency range order:
- L-band at 1 to 2GHz
- Ku-band at 12-18GHz
- Ka-band at 26.5-40GHz
Generally, the higher the frequency, the more data throughput is possible. Nevertheless, where the rubber meets the road, the reality is different.
Focusing on capacity, the quality of overall service becomes more important and providers are learning to combine different technology, hardware and third-party service software to attain the sweet spot of reliable connectivity.
In the near-term, business jets will more closely mirror office and home-like performance. The expectation of seamless professional web operations, day and night, is key to those seated in the cabin.
The greater satcom bandwidth will also need to accommodate live aircraft performance data as it downloads to update maintenance programs and flight department aircraft status tracking.
This is in addition to the already mature flight-path tracking, in use by many flight operations today. However, with the introduction of ADS-B (and ADS-C, and Spaced Based ADS-B), the way flight tracking is accomplished could change.
In the longer term satcom systems will remain connected across the globe handling large amounts of data, and so it is likely the focus will shift to how we can push the processing of data off the aircraft and into ‘the Cloud’.
In the medium term, manufacturers will strive to meet customer expectations, including the trouble-free installation of satcoms, the intuitive set up of the aircraft, and system performance as advertised.
Unfortunately, while much improved, the latter challenge still exists with MROs and patient aircraft owners today.
As December 31, 2019 approaches significant attention is being given to ADS-B Out. But the ‘Out’ part is only half the story.
Few business jets have ADS-B In or are even provisioned to receive it. As is common (and understandable) in the industry, a typical operator will request to “only upgrade with what is necessary to meet the compliance requirements for my specific aircraft”. ADS-B In requires additional equipment or modifications to display other aircraft and their ‘intention’ data. Above all, it is optional.
Space-Based ADS-B (SBA) may present a different situation for operators.
For the foreseeable future, there will not be a mandate, particularly if you have ADS-C (Contract) using satcom today. You will be able to use your existing ADS-B active system and then subscribe to a third-party service provider to receive and share available global SBA data.
Of course, as has been promoted to sell ADS-B in the first place, this technology will be offering more services soon, enabling greater throughput at busy airports, tracking aircraft in remote regions, providing better enroute surveillance, spacing and coverage, beyond that of existing radar.
With SBA, these capabilities will further extend to oceanic and remote continental flight paths.
Traffic Collision & Avoidance (TCAS) version II, with software version 7.1, is the latest iteration of the business jet and turboprop ‘aircraft to aircraft’ avoidance system. Moving into the near future, these systems will leverage improvements from the efforts being conducted by RTCA, NASA and others, centered on Detect and Avoid (DAA).
The goal is to establish a DAA ‘well-clear’ (DWC) suitable for remote-piloted aircraft, and later autonomous aircraft. For sure, a very robust surveillance resulting in a deterministic algorithm will be required.
Manned, remote and unmanned aircraft will need to monitor each other’s heading, altitude, climb rate, and airspeed at a minimum for corrective and warning alerts, with guidance to maintain DWC.
This, in turn, will later shape the ‘spherical’ aircraft, with a virtual buffer of airspace around the physical craft that helps to prevent unwanted penetration.
Future TCAS will be ACAS-X, and Xu for larger unmanned air vehicles. Think of near-future TCAS advancement as providing more avoidance choices to the pilot of a manned aircraft or remote pilot of unmanned.
This will be possible by including more predictability into the decision algorithm, borne out of intelligent data.
The data used is statistical and weighted by dynamic threat level. Because data processing will become faster and use a wider bandwidth, ACAS-X (and Xu) systems will respond rapidly with updated 4D navigation guidance.
Lastly, ACAS will monitor more of its own-aircraft systems, including Advanced GPS and Space-Based ADS-B.
Different to the long-term, this is where everything will be autonomous, providing plenty of redundancy via built-in provisions, countering failure at any level.
FIGURE A: Comparison of anticipated ACAS-X to existing TCAS 7.1, indicating differences around advisories and warnings, covering ‘monitor vertical speed’ (MVS), climb and descend altitude bands, over time
GPS L1/L2 and L5 (GPS III)
GPS uses two L-band frequencies for navigation with the L2 frequency newer than L1. The L2 allows GPS operation through various obstacles and because there are two frequencies involved, provides for more accurate positioning.
GPS L5 is due to be added in the 2021-2023 timeframe and its contributary benefit for aviation will be significant: L5 is to be used for safety-of-life in aircraft. However, for aviation, the real improvement is the introduction of GPS III before 2025, using the L5 frequency and new versions of L1 and L2, as L1C and L2C.
GPS III will be deployed across 10 new satellites, to be supplemented later by another 22 GPS IIIF satellites, both under a Lockheed Martin program. Position accuracy can be anticipated to be between 1-3m.
Importantly, it will also be interoperable with other global GPS networks, improving navigation performance even further.
While all this is underway, the unmanned aviation community is embracing Real Time Kinetic (RTK) GPS that requires a local base station, dramatically improving the GPS L1 position accuracy.
This works well for local operations and could be useful for the emerging eVTOL world.
Elements of RTK should find their way into future aircraft where there are familiar enroute flight paths, followed or preceded by repeated precision 3D landings in confined spaces.
GPS is the cornerstone to so much of what we expect the future of navigation and surveillance to be. However, redundancy considerations and tamper-proofing guarantees will be foremost in the minds of regulators and manufacturers alike.
One of 10 x GPS III satellites, as launched under the Lockheed Martin program (photo courtesy of Lockheed Martin Corporation)
The orientation of an aircraft with respect to the Earth’s surface has been a standard feature of all aircraft since the birth of aviation. Business jets have experienced an evolution of gyros throughout their total life.
Today we use laser reference gyros and smaller compact packaging, leading to less SWaP(C) – size, weight and power (plus cost).
The demand for better SWaP(C) is even greater with drones and eVTOLs, while the precision of such devices is also critical, due to the way drones and eVTOL operate.
Because GPS and Inertial Positioning (Management) are both contributing to the aircraft’s combined orientated position, we are now seeing elaborate micro-devices accomplishing attitude, heading, global position and more, all in the same package.
These will later be embedded in flight management systems. Of course, in the very long term, inertial management will be limited to on-board micro sensors, having moved all processing into a cloud-based avionics processor.
Advanced Flight Path Vector (APV)
It has taken forever for business jets to embrace head-up displays (HUD). As a result, the term ‘flight path vector’ is foreign to many pilots. The flight path vector adds dynamic attitude as a reference to the flight director cue.
This has been crucial to HUD operations, where pilots — in some instances — can take the aircraft to a Category III decision height using instruments before taking over manual control.
APV will introduce this now useful HUD tool to most flight decks, with or without the new helmet displays. It will dramatically improve the flight phase of ‘continue the descent to flare and touch down’, where multi-spectral sensors now aid pilots during poor visibility.
The addition of synthetic vision and millimeter wave to the spectral sensor package will truly be a game changer for aircrews. In the distant future, these evolving capabilities will enable fully autonomous operations.
Advanced Air Data & Flight Control
The climate is beyond our control, so we will always need to sense air density, pressure and other atmospheric parameters. How we integrate, process and use this data is in human hands…
Expect to see the combined air data flight computer in an aircraft soon. Flight computers will become predictive, anticipating an aircraft’s next move.
Because there will be an increasing demand for 3D operations, coupled with 4D navigation, the ability of the flight control system to perform will be crucial in so many ways.
4D operations will ensure automated arrivals at sequential waypoints, at specific points in time.
The APV associated with take-off and landing will later apply to each leg of the flight, automatically adjusting the aircraft attitude, speed, heading, roll, pitch and yaw rate to ensure 4D navigation requirements are met.
Real-Time Remote Operations
With high density airspace operations, where spacing demands and the simultaneous accommodation of all the different types of aircraft will be a challenge, real-time remote operations will become essential.
There are two key elements to these operations. One is real time and the other is remote. Remote can suggest many interpretations of off-board control, but it starts with current features of air traffic control such as FANS and Data Comm Departure Clearance that are in a sense remote.
Unfortunately, human reaction time will not suffice in the long term and we are beginning to see changes that circumvent human steps in the process. Instructions are shifting to remote commands and responses, leading to virtual real-time operations.
Essentially, real-time is a dream, but we can get closer to it and therefore permit much greater throughput with greater predictability and reliability, not subject to human fallibility.
Encryption & Cyber Protection
The further we move from manned operations, the more decisions will be made electronically, and the more vulnerability will exist. In concert with the rapid changes taking place in aviation there has to be corresponding security.
Security is not to be confused with failure mitigation, achieved by adding multiple similar systems for redundancy protection. It is not about quality or reliability.
Security is only one link in the safety chain. Security is about protecting data and the continued operation of active systems on aircraft, as well as for air traffic control.
Unfortunately, as we all know, the more intelligent the protection devised, the more hackers and those with ill intent will rise to the challenge.
If encryption and cyber protection can keep up with technology’s evolution, it will not delay progress. But this is unlikely. We can expect to see other changes in our aircraft systems within the near future. Changes will reduce the ability to hack, shut down or interfere.
Duplicate electronic clouds operating in different ways, at different frequencies, can be a long-term mitigation, but expect to see increased sophistication of what we have available in the not too distant future.
What to Expect…
The near-term evolution of avionics will see a continuation of the familiar with the addition of security certification and interoperability between technologies. By improving cyber security and integrating various sensors, industry will accommodate the concerns of regulators and enable virtual real-time operations.
Through improved capability and performance, industry will meet the demands of operators and national airspace alike. By reducing SWaP(C), business aircraft technologies will migrate into drones and e-VTOL, while game-changing Commercial off the Shelf (COTS) technology, now in drones, will mature and achieve their certification path into business aircraft.
Multi-spectral sensors, enhanced by adding millimeter wave and synthetic vision, will begin to incorporate LiDAR (Light Detection and Ranging) as another aid to navigation.
Above all, we’re seeing a gradual morphing of avionic technologies into Communication and Navigation/Surveillance (as one), and cabins that increasingly mimic our home entertainment or office environments.
All of this, along with live performance tracking, will extend to a global deployment of fully monitored and connected piloted aircraft. Remote pilots and autonomous operations are inevitable, if far into the future, but we do need to work through the challenges today.