Embedded Computer Systems

The Air Force originally anticipated "low-risk" software development for the C-17 aircraft program, but the effort has proved much more complex and risky than planned, GAO testified. The Air Force planned to use operational software previously developed and tested for other systems and proven avionics technology to reduce the complexity and technical risks associated with C-17 development. It expected to have full operational functionality for the C-17's first flight, originally scheduled for February 1990. However, for many critical C-17 functions, the prime contractor--a subsidiary of McDonnell Douglas Corporation--and its subcontractors could not simply reuse existing software but had to produce substantial amounts of new code. This unexpected development delayed schedules and changed development plans. The first flight test did not occur until September 1991--19 months after originally scheduled--and excluded many of the critical software functions required for the fully operational aircraft, such as certain key navigational capabilities. These functions are not expected to be ready until the spring of 1992 at the earliest. Further, in providing software for the first flight test, shortcuts were taken that will likely cause further delays and increased costs.