MIL-STD-1798 Mechanical Equipment And Subsystems Integrity ProgramThe purpose of this standard is to describe the general process to achieve and maintain the physical and functional integrity of the mechanical elements of aircraft systems. The goal of this integrity program is to achieve the desired level of safety and aircraft availability at the most economic cost across the life cycle of the weapon system. This standard allows the process to be tailored in a competitive environment to meet specific equipment, subsystem, and/or system requirements. The Mechanical Equipment and Subsystems Integrity Program MECSIP is implemented in the planning process and continued until retirement of the system.

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MIL-STD-1798C

d.   Storage time accumulated e.   Load cycles

f.    Temperature cycles and/or extremes.

3.55  Serial number MTBF.

Mean Time Between Failure data is captured by serial number for individual components and is generally more accurate than fleet MTBF.  The maintenance data system should serially track critical parts (safety, mission), MSIs, all Bad Actors, TCIs, and special-attention components.

3.56  Severe Wind and Moisture Prone (SWAMP) areas.

These are zones on the aircraft exposed to severe wind, moisture and elevated temperatures. These areas are particularly likely to lead to degradation (aging) of wire insulation.

3.57  Similarity (legacy systems).

Similarity is when significant, successful operational experience on hardware of actual or similar design and usage has occurred.  Similarity is appropriate for mature designs susceptible to damage when other design verification approaches are not feasible/appropriate.  Consider the following to establish similarity:

a.   materials and processing;

b.   design configuration and usage;

c.   operating environment considerations including cycle temperatures and pressures, speeds, torques, and flows;

d.   legacy component hours or cyclic history, including number of parts produced, number and type of safety-critical or mission-critical events, total number of fleet hours, and high- time component.

3.58  Slow damage growth component.

A slow damage growth component is a component in which damage is not allowed to attain the critical size required for unstable rapid damage propagation.  Safety is assured through slow damage growth for specified periods of usage depending upon the degree of inspectability.  The strength of slow damage growth component with damage present is not degraded below a specified limit for the period of unrepaired service usage.

3.59  Technology needs.

Technology needs refer to potential technology insertions to solve subsystem development or sustainment challenges.  Each year the MECSIP Managers/Engineers are asked to identy their technology needs and that list of technologies are prioritized at the annual MECSIP technical interchange Meeting and submitted to the Air Force Research Lab for consideration for potential funding.

3.60  Test.

Test is an evaluation effort performed to prove contractual requirements have been met. Documented procedures, instrumentation, and known environmental conditions are normally applicable. Compliance or noncompliance is determined by trial, observation, and evaluation of collected data.  Most ground and flight structured evaluation efforts associated with procurement and acquisition qualify as tests.

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