MIL STD 810 G – Test Method 523.3 – Vibro-Acoustic and Temperature
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:
To reveal and correct design weaknesses (Test, Analyze and Fix (TAAF) test).
To determine whether a design meets a specified reliability requirement (Reliability Demonstration test).
To reveal workmanship or component defects before a production unit leaves the place of assembly (Screening test).
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).
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).
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:
development of a more reliable store design prior to production.
assessment of the potential for satisfaction of the reliability requirement for a store.
manufacturer’s internal testing to assure delivery of reliable units during production.
determination of the acceptance of a lot prior to delivery.
determination of the relative differences in quality from two sources for establishing production buy proportions.
This method is not intended to provide for:
An environmental design qualification test of a store or any of its individual components for functionality. (For such testing see Method 500.5, Altitude; Method 501.5, High Temperature; Method 502.5, Low Temperature; Method 503.5, Temperature Shock; Method 507.5, Humidity; Method 513.6, Acceleration; Method 514.6, Vibration; Method 515.6, Acoustic Noise; Method 516.6, Shock; Method 517.1, Pyroshock; and Method 520.3, Temperature, Humidity, Vibration, Altitude).
An environmental design qualification test of a store airframe or other structural components for structural integrity.
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.
The following general procedure will vary depending on the test type conducted as shown in Table 523.3-I:
Step 1. Prepare the test item in its test configuration as described in paragraph 4.5.3.
Step 2. Verify the functional status of the test item.
Step 3. Start the test using conditions specified in the test plan developed from test tailoring guidelines.
Step 4. Conduct the test and monitor the operational status of the test item per paragraph 4.5.3.
Step 5. If a test item failure occurs, refer to paragraph 4.3.2.
Step 6. If a test interruption occurs, proceed according to the procedure called out in paragraph 4.3.1.
Step 7. Continue the test until termination criteria are met according to the procedure called out in paragraph 3.1.b(5). Document the results for comparison with pretest data.
NOTE: Tailoring is essential. Please, ask to your confidence laboratory for further details about tailoring of test methods.