1.1 Purpose
The vibro-acoustic/temperature procedure is performed to determine the synergistic effects of vibration, acoustic noise, and temperature on externally carried aircraft stores during captive carry flight. Such determination may be useful for, but not restricted to the following purposes:
- a. To reveal and correct design weaknesses (Test, Analyze and Fix (TAAF) test).
- b. To determine whether a design meets a specified reliability requirement (Reliability Demonstration test).
- c. To reveal workmanship or component defects before a production unit leaves the place of assembly (Screening test).
- d. To estimate the Mean Time Between Failure (MTBF) of a lot of units based upon the test item’s time to failure of a small sample of the units (Lot Acceptance test).
- e. To determine the relative reliability among units based upon the test item’s time to failure of a small sample of the units (Source Comparison test).
1.2 Application
For captively-carried stores, this method is intended primarily to test electronics and other electro-mechanical assemblies within the store for functionality in a vibro-acoustic/temperature environment. As an incidental part of the testing, thermal variation may induce changes in moisture exposure of the store and the effects of such exposure must be noted when interpreting the test result data. Typical applications include:
- a. development of a more reliable store design prior to production.
- b. assessment of the potential for satisfaction of the reliability requirement for a store.
- c. manufacturer's internal testing to assure delivery of reliable units during production.
- d. determination of the acceptance of a lot prior to delivery.
- e. determination of the relative differences in quality from two sources for establishing production buy proportions.
523.4-1.2 Application
Information in this annex is designed to provide some, but not necessarily all, of the details that must be considered in developing a Vibro-Acoustic/Temperature test profile. Information included here should allow the practitioner to develop the test profile for any of the possible test types provided in Table 523.4-I.
1.3 Limitations
This method is not intended to provide for:
- a. An environmental design qualification test of a store or any of its individual components for functionality. (For such testing see Method 500 Altitude; Method 501 High Temperature; Method 502 Low Temperature; Method 503 Temperature Shock; Method 507 Humidity; Method 513 Acceleration; Method 514 Vibration; Method 515 Acoustic Noise; Method 516 Shock; Method 517 Pyroshock; and Method 520 Temperature, Humidity, Vibration, Altitude).
- b. An environmental design qualification test of a store airframe or other structural components for structural integrity.
- c. Any test to satisfy the requirements of the Life Cycle Profile except that for the combined vibration, acoustic, and temperature environments related to reliability testing.
MIL-STD-810H
METHOD 523.4