As avionic systems become more complex, realistic qualification requirements for the flight-critical systems becomes more important, but more difficult to define. Requirements developed to establish acceptable levels of performance must be verifiable if they are to have any meaning. This article shows that both the current FAA requirements of flight-critical systems and the FAA recommended methods for probabilistic assessment are flawed, and result in "required" safety assessments which are misleading. Alternatives are then explored.

The Qualified Manufacturer List (QML) approach, detailed in MIL-I-38535, General Specification for Integrated Circuits (Microcircuit) Manufacturing, embraces many of the commercial practices employed by high volume microcircuit suppliers, Nevertheless, with the availability of highly reliable and lower cost commercial parts, the QML approach becomes unnecessary and undesirable.In this paper we attempt to show why US government support of the QML program is leading the military and government to unaffordable access to out-dated technologies, damaging our country's military and avionics position.We will present information to show why we support the retraction of MIL-PRF-38535 and any other documents which imply that QML parts are superior to commercial parts, including those of QPL, MIL-STD-454, and MIL-HDBK-217 (now prohibited from use in all new Army programs).

This paper compares the failure rates of several families of plastic encapsulated microcircuits (PEMs) using both field & test data (test data are converted to device failure rates for field conditions using common acceleration equations) and Mil-Hdbk-217 calculations. Calculated failure rates are obtained from the Mil-Hdbk-217F for both plastic encapsulated and ceramic hermetic class-B microcircuits. Comparisons show that the results from Mil-Hdbk-217 are misleading and that the US military and Government part-selection methods should not be burdened by this -217 methodology.

It is noted that with cutbacks in the military and the changing international economic environment, there is a growing perception that the military must rely on commercial industries in order to afford the next generation of high-performance and high-reliability military systems. What is not clear is whether an industrial base for the defense can be provided and maintained without dramatic changes in the operation of both the government and commercial industry. The authors examine one issue associated with this question-whether commercial standards can effectively supplant military standards and still provide high performance and reliability for military missions