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

5.2.2 Environmental emissions.

Analyses of the mechanical equipment operating environment shall be performed to identify any emissions that may affect aircraft operation or the safety of ground personnel. Examples of

these emissions include: electromagnetic energies, noise, smoke, acoustics, fuel or oil vapors, and overboard leakage.

5.2.3 Physical and operational interfaces.

Analyses of subsystems shall be performed to identify and characterize all internal and external physical and operational interface design concepts and requirements. Examples of these include: control/diagnostic/crew-warning interfaces, functional and physical connections, input/output electrical/electronic signals, electrical power supplies, mechanical power take-offs, gearbox speeds, torques, temperatures, flows, etc.

5.2.4 Design service life/design usage.

Design mission profiles, mission mixes, and environmental exposure mixes which are realistic estimates of expected service usage shall be established based on System Specification requirements. Subsystem/component design criteria (stated in operating hours, flight hours, cycles, loads, environment, etc.) shall be derived to reflect component/system usage and service life.

5.2.5 Supportability planning.

Analysis of subsystems shall be performed to identify top-level support concept for each subsystem. This analysis shall:

a. identify which equipment will include periodic inspections or life limits (when practical, safety-critical equipment should have life limits defined);

b. identify equipment planned for inclusion in a Reliability-Centered Maintenance program;

c. develop a plan for what equipment/subsystems will include prognostics capability; and

d. a listing of components planned to be "removed for cause." "Remove for cause" shall not be utilized on any safety-critical components.

5.2.6 Prognostic Health Monitoring (PHM) planning.

Each safety-, mission-, and durability-critical component shall be evaluated for application of PHM. Where application of PHM is determined to be technically feasible, a trade study shall be conducted to evaluate the cost of PHM (recurring and non-recurring) with the estimated benefit (reduced repair cost and reduced maintenance man-hours, NMC and PMC time).

5.2.7 Initial Failure Modes Effects and Criticality Analysis (FMECA).

The contractor shall build the initial FMECA during Task II. This will be used to identify single point failures in the system, particularly those single point failures which will result in safety- or mission-critical components as early as possible. The FMECA will be a key document in identifying safety- and mission-critical components. The FMECA will be a living document which is maintained as current throughout the life cycle of the weapon system.

5.2.8 Initial Hazard Analysis (HA).

The contractor shall build the intial HA during Task II. The HA will be used in the components classification task. The HA shall be a living document which is maintained as current throughout the life cycle of the weapon system.