Boeing is providing more detail about plans to improve the in-service reliability of the 787-8, some of which involves evaluations of revised software during on-going flight tests of the stretched 787-9.
Although the company acknowledges it still has much work in front of it to combat the ‘teething troubles’ early in the 787’s service life with the electrical system, batteries, hydraulics, brakes, oxygen system and others, it says the chief focus is now fixed on rationalizing the aircraft’s very sophisticated software.
The 787’s software-intensive control and monitoring systems measure vast amounts of data, far more than any previous airliner.
As a result, this has triggered an unexpectedly high number of low-level nuisance alerts that have led to inadvertent higher-level events, turn-backs and diversions.
The aircraft has been internally dubbed by Boeing as a systems ‘hypochondriac’, flagging notices to flight crews who are trained to err on the side of caution. “We are looking at software improvements to reduce the number of nuisance warnings and improve the built-in-test equipment (BITE) capability,” says 787 Airplane Development vice president Mark Jenks.
Although Jenks is keen to point out that Boeing is not trying to ‘dumb down’ the software, “we’re doing things to simplify it. The 787 system has more data than it needs – it’s a very smart airplane. So we are fine tuning that in some areas.”
The heart of the 787’s avionics system is the GE Aviation Systems-developed common core system (CCS) which uses a network of 21 remote data concentrators located throughout the aircraft to consolidate data from systems and sensors. The information is distributed via a Rockwell Collins-supplied full duplex switched Ethernet network. The CCS runs on the VxWorks 653 real-time operating system (RTOS) developed by Wind River, a wholly-owned subsidiary of Intel.
The process is being dovetailed with flight tests of the 787-9 with simplified loads flying on the initial test aircraft. In addition, results from investigations into system call-outs or ‘squawks’ from the heavily instrumented 787-9 test aircraft are being rolled back into the software update. Revised software loads are being prepared for installation throughout the fleet with operators such as Air India expected to begin updating its aircraft in December.
Commenting recently on the focus on improving the software, Boeing President and CEO Jim McNerney says, “improving dispatch reliability of the 787 is one of our top priorities. We are not satisfied with the fleet-wide performance, even though it is at 97% on average. There are some customers who are not at that level and we’re not pleased about that. We still have more work to do and while we are otherwise pleased with feedback in areas like fuel burn, we will not be satisfied until we meet customer expectations across the board.” McNerney says ironing out issues with the software heavy is a key priority. “Old messaging (in the software) is roughly one third of the issue. It’s frustrating for us and very frustrating for our customers. It’s an all hands on deck effort.”