Garent Ridgway: In the short term, it is undeniable that the directly proportional relationship between time and money holds true. However, accelerating a test program can be fraught with project risks. Testing is often a compromise between ‘what we’d like to do’ and ‘what we have time to do’, and prioritizing can be a delicate balance. Without sufficient time for analysis of data captured during earlier testing, it’s extremely difficult to inform the choice of subsequent tests; this can lead to unnecessary repetition or omission of test points. On this basis, faster testing isn’t necessarily leaner testing.
A slower, more measured test program also enables a closer and more productive relationship between the test and design communities. This can be achieved through an iterative test/modify/retest approach, which seeks to highlight potential problems and address them as an intended (and budgeted) part of the test and evaluation process. Note that this is distinct from the unintended emergence of design deficiencies during testing (often caused by a rushed design process) for which there is no time or budget to address.
Another benefit of a slower and well-thought-out test program is the ability to match the testing as closely as possible to the intended role of the aircraft across its whole service life. Testing programs with tighter schedules are more susceptible to seduction by the current role of similar aircraft, for example by the demands of operating in a particular theater. This can be to the detriment of the long-term life of an aircraft, which may end up being unintentionally optimized for a role that is no longer relevant by the time it enters service.
The need to work to compressed timescales is deeply ingrained in the aerospace community, quite possibly because of its close ties to the defense sector and the fiercely competitive civil aviation market. In the past, this may have been a necessity given the short service lives of aerospace products driven by the rapid advances in technology. However, aircraft
are lasting longer and longer; for example, the USAF’s B52 bombers are scheduled to remain in service until 2045, some 90 years after their introduction. When working to such timescales, the question must be asked – isn’t it worth taking an extra year to get the test program right in the first place?
Garnet Ridgway has a PhD from the University of Liverpool. He has designed cockpit instruments for Airbus and currently works for a leading UK-based aircraft test and evaluation organization.
Sophie Robinson: As my sparring partner on the left-hand side of the page has already stated, employing a fast-paced testing program does have financial benefits; it’s hard to argue with that. The old adage that ‘time is money’ will always ring true in the testing community. However, a dynamic, fast-paced testing program can offer a raft of other benefits too.
Fast testing can mean lean testing. Quickly generating a broad overview of aircraft performance can enable future testing to be refined and targeted, informing ‘what we’d like to do’, rather than doing things ‘the way they’ve always been done’. This approach also enables testing to be prioritized in a way that maximizes return on effort – for example, targeting particular areas of the flight envelope to allow the largest possible envelope to be provided to the operator.
The use of a fast-paced test program also endows projects, and those who work within them, with a strong focus and sense of direction. This creates a positive project culture, reducing the likelihood of delays; delays that can be costly both financially and in terms of operational efficiency. A challenging test program can also provide collective motivation in situations where those involved can often have conflicting priorities, encouraging cooperation and collaboration in order to achieve a common goal.
Tight deadlines and rigorous scheduling also lend themselves well to operation and cooperation with military stakeholders; fitting into an already existing culture of stringent planning and rapid decision making can often be both easier and more successful than trying to convert everyone to a new methodology of working.
The rapid entry into service of a new platform is often a very desirable outcome in both military and civilian sectors. New platforms are often intended to fill gaps in capability and meet urgent operational requirements (such as responding to unpredicted occurrences, such as earthquakes or flooding). Using a dynamic approach to testing can allow new platforms to enter service more quickly, even if their initial capability is reduced. This also means that future testing requirements can be rapidly identified and targeted toward the current user requirements; there’s no point developing aircraft capabilities that won’t be used in theater or prioritizing testing for future operations.
Ultimately, a fast-paced test program provides both financial benefits and targeted testing, while remaining reactive to user needs – something which is of considerable value in both the rapidly changing military and commercial sectors.
Sophie Robinson is currently finishing her PhD as part of the Flight Science and Technology Research Group within the Centre for Engineering Dynamics at Liverpool University. In the course of her research, Sophie regularly works with test pilots.
