Lockheed Martin’s F-35 shows the impact that delays and cost overruns in safety-critical airborne software could cause in new platforms. In April, the U.S. Government Accountability Office (GAO) published a 49-page report noting that F-35 testing delays could cost the Defense Dept. an additional $1 billion, on top of acquisition costs that have already totaled $400 billion.
Delays are the result of problems with the aircraft’s Block 3F mission software, which provides all of the required software, including data link imagery, full weapons and embedded training. However, according to GAO, F-35 program officials have had to regularly “divert resources from developing and testing of more advanced software capabilities to address unanticipated problems with prior software versions.”
Arizona-based software and engineering services provider Performance Software Corp. recently published its list of the top 10 mistakes made by real-time embedded software engineers working in avionics. The top mistake cited was use of global variables, which the company noted is “often frowned upon by software engineers because they violate encapsulation criteria of object-based design and make it more difficult to maintain the software.”
The company’s Performance Virtual Platform allows for custom interactions with virtualized hardware and was previously used to support Boeing 787 requirements for software development testing. One of the factors that impacted that effort was the reliance upon production hardware for ground-based testing.
Tim Bigelow, chief development officer for Performance Software, said that the company’s new JETS Virtual Platform can create a direct replica of the target hardware that will use the software the company is developing by virtualizing any custom system on chip and by allowing developers to run the same binary they would on the target hardware.
“Our vision of the future is that this will be the new software for highly regulated systems, not just aerospace, but defense products, self-driving vehicles, anything that is highly regulated and mission critical,” said Bigelow.
New avionics software development tool suites are designed to reduce the time required for testing and certifying the overall application software code base. This is accomplished by featuring complete sets of DO-178 certification artifacts the developers can quickly incorporate within their overall certification documents rather than develop those documents from scratch.
That is the approach that Ensco Avionics has taken with its iData cockpit display development tool and its new IGL software rasterizer.
Its latest activity focused on reducing the cost of developing, certifying and maintaining in service safety critical avionics software focuses on introducing a software rasterizer that eliminates the need for additional hardware is being introduced into an avionics system development program.
Embedded cockpit systems require graphics processing units to populate displays with moving maps, cursors, airspeed indicators and other elements requested by customer advisory boards used by OEMs.
In July, ENSCO Avionics announced a technology partnership with Core Avionics & Industrial Inc. (CoreAVI), a supplier of real-time graphics and video drivers, to introduce IGL, a new safety certifiable graphics rendering engine. IGL, according to Tom Matarese, director of business development for Ensco Avionics, is designed to eliminate obsolescence challenges associated with hardware that changes much faster than the average in-service life of an aircraft.
“IGL is unique by providing implementation flexibility in multicore, hypervisor and multipartition applications as either a primary graphics engine or as an add-on to a GPU-based processor system,” said Matarese.
Tools for creating embedded graphics software for safety-critical cockpit display applications have continued to evolve to today’s standard drag-and-drop capabilities using a variety of existing user interface prototypes. Some of the industry’s other most widely used embedded avionics graphics software creation suites include the Presagis VAPS XT, Esterel Technologies’ model-based design and development environment for embedded human machine interface elements, the SCADE display tool.
The Open Group’s Future Airborne Capability Environment (FACE) initiative is one of the industry’s leading projects with a stated goal of helping to reduce not only the development of new avionics software, but also the headaches that come with trying to rectify issues with such software once it is in service, and also to increase the reusability of existing software. A key element for the initiative is the FACE technical standard, which provides requirements for constructing avionics software.
The latest progress for the FACE consortium includes the release of the 3.0 edition of the FACE Technical standard, which Judy Cerenzia, director of the FACE Consortium, says is scheduled to publish in mid-November.
“Key among the new elements of FACE technical standard, edition 3.0 are improvements in the data architecture area, which is eventually going to be split out into its own independent standard that provides the opportunity to support interoperability across adjacent markets with common data architecture and language that are synergistic with avionics,” she says.
According to Cerenzia, the focus for FACE is to standardize software and establish business incentives for reuse, to change the way the government procures avionics software and the way that vendors provide it as well.
“All of the U.S. Army’s platforms are either implementing FACE compatible capabilities, or are designing in the FACE conformant capabilities in the early stages, or have requested info for what FACE based capabilities are out there that they can use. For example the Cargo PM put the auto re-router capability onto its platform,” says Terry Carlson, the CIO of the Army’s PEO Aviation.
Another major activity aimed at driving the costs of producing new avionics software from the ground up is the consortium’s Basic Avionics Lightweight Source Archetype (BALSA), which Cerenzia describes as a very simplified computing environment where programmers can take software that they have developed to align with the FACE technical standard and actually integrate with various segments of FACE tech standard without dealing with the complexity of a full avionics system.
“Different vendors and suppliers of both FACE software components and COTS software are using the BALSA framework to start a grounds up integration of a FACE solution stack,” says Chip Downing, senior business development director for aerospace and defense at Wind River, chair of the FACE consortium business working group, and outreach committee lead. “We are finding that once the FACE architecture is understood it gets far easier than one expects to do these integrations.”
Boeing’s Future Approach to Avionics Software
In August, Boeing said it would launch a new business unit focused on the development and production of avionics technology. The new avionics team is focusing on developing these technologies for “systems that are targeted for entry into service in the next decade,” according to a Boeing internal employee memorandum.
Prior to that announcement, at the 2017 Paris Air Show, Boeing VP Mike Sinnett discussed future-facing airframe design, flight control, engine configuration and avionics software with aerospace journalists.
“Flight-critical software continues to be developed and tested and deployed as it is today, but I believe there is going to be advisory capability that’s done in a different way,” said Sinnett. “Trying to understand what that non-deterministic advisory capability is and how that would be deployed, that’s work ahead of us still.”
He also referenced how Boeing’s aircraft types have consistently increased in code, from 1 million lines on the 747-400 to 6 million lines on the 777 and 20 million on the 787. Sinnett said already on the 787, airlines can deploy new software electronically. However, they would like to continue to evolve the ease of upgrading to new software, similar to “automobiles today where they download their own software overnight.”
“We’ll take more advantage of COTS and more advantage of advisory, but I think we’ll still do the flight-critical things the way we have because that’s worked,” said Sinnett. AVS