- Every device creates its own opportunity for human error.
- Exotic devices create exotic problems.
- Digital devices tune out small errors while creating opportunities for large errors.
- Invention is the mother of necessity.
- Some problems have no solution.
- It takes an airplane to bring out the worst in a pilot.
- Whenever you solve a problem, you usually create one. You can only hope that the one you created is less critical than the one you eliminated.
- You can never be too rich or too thin (according to the Duchess of Windsor) or too careful about what you put into a digital flight-guidance system (Wiener).
Wiener pointed out that the effect of automation is to reduce the cockpit workload when the workload is low and to increase it when the workload is high. Nadine Sarter, an industrial engineer at the University of Michigan, and one of the pre-eminent researchers in the field, made the same point to me in a different way: “Look, as automation level goes up, the help provided goes up, workload is lowered, and all the expected benefits are achieved. But then if the automation in some way fails, there is a significant price to pay. We need to think about whether there is a level where you get considerable benefits from the automation but if something goes wrong the pilot can still handle it.”