Daily Predive Procedures (Cont)

TM 5-4220-225-14 Table 2-3. Daily Predive Procedures (Cont). Step Procedure 2. HELMET ASSEMBLY NOTE (Internal Checks) Set helmet on its front viewport.Inspect helmet interior for overall cleanliness.There should be no evidence of foreign matter, oil or moisture, particu- larly on helmet liner. a. Ducting Check. (1) Ensure ducting is properly installed. (2) Inspect ducting open ends for dirt, oil, and moisture. b. Communication System Check. (1) Inspect the helmet wiring for cut or nicked insulation, and loose, dirty, and wet connections. (2) Ensure that earphones are clean, dry, and properly mounted in the retainers. (3) Ensure that microphone is clean, dry, and securely mounted. (4) Visually inspect the communication whip and umbilical cable assemblies for outer cover damage; chafing, abrasions, cuts, and blisters.Check for coupling damage, corrosion, dirt, oil, and missing or damaged preformed packing. (5) Connect the communication whip and communication station to the communication/strength cable. 3. OPERATIONAL TESTS a. Vacuum Test. Perform vacuum test of the nonreturn valve in accordance with paragraph 2-8, a. b. P, Flow, and Leak Tests. Perform P, flow and leak tests, in accordance with paragraph 2-8, b. c. Communication Check. Perform a communication check between the helmet and station for proper communication and volume 2-34