Part Two in a series looking at the status of Enhanced Flight Vision Systems (EFVS), which provide greater situation awareness and improved visual clarity for enhanced navigational safety and efficient operations.
Synthetic Vision
Synthetic vision guidance systems provide pilots with a synthesized, clear view of the terrain and navigational guidance, even when the view out the window is obscured by weather conditions or low light. Collins’ synthetic vision system provides ground navigation data for pilots landing at small airfields.
Thea Feyereisen, senior technical fellow at Aerospace Advanced Technology, Honeywell, Minneapolis, says Synthetic Vision Guidance System (SVGS) components include synthetic vision (terrain and obstacle database), high-integrity runway database, ownership position monitors and advanced symbology (i.e., HUD-like including flight path vector, speed deviation and acceleration cue) to enable the pilot lower than standard minimums.
“EFVS enhances this synthetic view with real-time images, giving pilots a complete view of their surroundings through the HUD in any operating environment,” Brown says. Collins Aerospace’s real-time 3-D terrain mapping creates precise virtual representations of the environment—such as terrain, obstacles, airports and runways—to provide a comprehensive picture of the pilot’s surroundings to enhance situational awareness.
“We’ve also developed Combined Vision Systems (CVS) which integrates SVS with Enhanced Vision Systems (EVS) and are visible on our high-definition Head-Up Displays (HUD),” Brown says. “CVS is available for a wide variety of aircraft, including those operating the Collins Compact HUD. These technologies seamlessly blend to provide a holistic view of the environment, high-fidelity flight information and a wider field of view to lessen pilot workload and improve critical decision making. When pilots see the Collins CVS, they are blown away by the quality of the imagery. The fidelity and detail provided are a game changer for pilots who need to operate in any environmental condition.”
SVGS capable aircraft can enable pilots to fly a special authorization Category I Instrument Landing System (CAT I ILS) to 150 feet vs 200 feet Decision Altitude/Decision Height (DA/DH). “In the future SVGS will enable lower minimums on unrestricted LPV approaches from 200 to 150 and reduce further the minimums on CAT I ILS from 200 to 100 (today is 150 feet) DA/DH,” Feyereisen says. “An SVGS approach extends the instrument segment, whereas and EFVS extends the visual segment of the approach. An aircraft equipped with SVGS can lower the altitude (e.g., detect at 150ft vs 200ft) from which the runway environment cues must be seen by the pilot with the EFVS sensor to transition to visual approach and landing.”
Both SVGS and EFVS aim to enhance situational awareness in low-visibility conditions, but their primary difference lies in the technology used and the operational credits they provide. Yahav contends, “SVGS provides limited operational credit in certain scenarios, while EFVS provides significantly more credit, deeming SVGS irrelevant when EFVS is installed. SVGS continue to be limited, requiring head-down operations to look at the graphical displays installed on the flight deck. We believe flying should be performed heads up, with pilots focused outside the cockpit on their surrounding environment.”
Artificial Intelligence and EFVS
Artificial intelligence (AI) is playing an increasingly beneficial role in EFVS during flight. According to Brown, “AI algorithms can process and enhance images, detect and recognize objects within the aircraft’s vicinity, and identify potential terrain and obstacle hazards.”
With obstacle recognition and detection, Feyereisen says, the SVS picture in general, is always going to be more consistent and “better looking” than the EFVS. “However, the SVS is not real time, so it does not detect a hazard that is not in its database, e.g., a moose that has stumbled onto the runway! MMWR have excellent all-weather penetration capabilities, but the image quality and update rate for a commercial system does not meet the required visual quality requirements to be equivalent to natural vision like today’s IR sensors.”
One concept being explored is leveraging AI for image/obstacle detection to confirm runway location and hazard detection to extend the capabilities of SVGS/SVS. Kumar believes the pilot gets to fly with the well-formed and useable SVS, but there if there is an issue with the navigation position or an unanticipated obstacle like a vehicle or animal on the runway, the pilot would maintain situational awareness equivalent to visual conditions.
“The fusion of different data modalities, i.e., radar, lidar, cameras, and real-time position and high integrity databases through machine learning and AI processing has made significant progresses toward autonomous vehicle operations in urban environment,” He says. “The advancement can potentially be leveraged into aviation domain for improving EFVS systems.”
Universal Avionics began incorporating artificial intelligence with Aperture long before the AI revolution. A lot of information is captured from video sources, not all of which can be processed by the human brain in real time to make proactive decisions quickly. “We are leveraging AI to better understand the video captured from our enhanced vision system,” Yahav says. “This is similar to the automotive industry’s autopilot features, which rely on visual information captured by cameras and sensors to navigate the vehicle. Universal’s Aperture will be the first product to bring this sensor-fusion technology to aviation, first certified last year and already being developed in OEM solutions by our customers.”
EFVS Regulatory Updates
The FAA continues to define new standards for EFVS through their work with the RTCA SC-213 special committee. “Co-chaired by Universal Avionics and represented by Troy Niles, senior principal engineer for EFVS, the committee aligns with the latest developments of ClearVision and is backed by our subject expertise,” Yahav says. “Universal Avionics is also the first company to utilize the 50% operational credit allowed by the FAA. The FAA and EASA are also working together to define regulations for certifying AI, the same direction that Universal Avionics is moving towards with its upcoming avionics innovations.”
RTCA SC-213, which is harmonized with EUROCAE WG79, is expected to release two new Minimum Acceptable Performance Standards (MASPS) later this year: Document DO-407/ED-326 for Synthetic and Combined Vision Systems and DO-408/ED-327 for Enhanced Vision Systems. Thea Feyereisen is chair of the SVS/CVS document and Randy Bailey, NASA, is chair of the EFVS/EVS document. Both documents have been sent out to the industry for final review and comment and the comments are in the process of being dispositioned.
Once that review process is complete, the documents will be sent to RTCA and EUROCAE management for formal approval and release. “The great thing about these new documents is that they combine content from multiple previous documents that have been released over the past dozen-plus years into one, making it much easier for applicants to point to just one (or two) documents, rather than having to work through multiple documents to identify the requirements and compliance demonstration,” Feyereisen says.
Brown explains that he is seeing, “regulatory bodies around the world update their guidelines to include EFVS operations, which will help bring the benefits of this technology to more parts of the globe.”
EFVS Looks to the Future
EFVS is here to stay, and Brown believes its future is bright. “The benefits for safety and more efficient operations are clear, and we believe these benefits will compel more and more operators to select this feature.”
With the changing of airfield lighting from incandescent to LED, Feyereisen cautions the visual advantage previously afforded to EFVS will be lost. “Operators are looking toward vision systems that provide enhanced situation awareness gate-to-gate.”
He believes advanced SVS features like 3-D airport moving map and SVGS capabilities, including lowering the instrument segment for both ILS and LPV approaches, will see more attention and emphasis. “Operators will want these enhancements to both the Head Up Display (HUD) and head down display.”
Overall, Brown predicts, “More and more aircraft OEMs and operators will make this a requirement versus a ‘nice-to-have’ as they learn about and experience the benefits of EFVS. We will see new and better cameras and sensor integration, along with AI to improve the qualities and usability of the systems.”
“We believe that the commercial market will follow the military market, as is the case with many other emerging technologies,” Yahav says. “Pilots will be able to fly heads up in all phases of flight, taking advantage of this intuitive operational capability. As EFVS technology becomes more available and affordable for general aviation, helicopters and commercial airlines, it will no longer be seen as a luxury add-on feature that is nice to have. Enhanced vision will become integral as a baseline configuration requirement for airlines looking to maximize safety, boost productivity, and meet sustainability initiatives.”