We increased their reliability by doubling their life limits.
If only Ansett had cast off, entirely, the closely held superstitions and beliefs, and put the autopilot gyros on condition instead.
Despite the time-honoured belief that reliability was related to the intervals between scheduled overhauls, searching studies based on actuarial analysis of failure data suggested that the traditional hard-time policies were, apart from their expense, ineffective in controlling failure rates. … Consequently, a maintenance policy based exclusively on some maximum operating age would, no matter what the age limit, have little or no effect on the failure rate. …