TM 5-4220-225-14
SECTION IV. OPERATION UNDER UNUSUAL CONDITIONS
Paragraph
Page
2-20
General ................................. ................................ ................................ ................................ ........ 2-55
2-21
Emergency Procedures ................................ ................................ ................................ ................. 2-55
2-20. General. This section provides procedures that are to be followed if faced with an equipment failure during
operations. Situations may occur that are not covered in these procedures. If so, follow unit operating procedures or
consult tender or diving supervisor.
2-21. Emergency Procedures.
WARNING
If an underwater emergency occurs, notify dive station and dive partner immediately.
Do not ditch the diving helmet. Failure to follow prescribed emergency procedures may
result in injuries to personnel.
a. Air Supply Valve Jammed Open.
WARNING
To prevent the valve from jamming under normal conditions, the supply valve should
never be fully shut or fully opened.
(1) Depress the chin button and open exhaust valve to prevent over inflation. Inform topside.
(2) Attempt to shut the valve; have dive partner attempt to shut supply valve.
(3) Attempt to crimp whip hose to reduce flow.
(4) If supply valve cannot be shut, diver's air flow will be controlled by topside. Ascend as directed.
b.
Air Supply Valve Jammed Shut.
(1) Shut the exhaust valve while attempting to open the air supply valve. Inform topside.
(2) Insert pneumofathometer hose under drysuit cuff or neck dam and request a continuous vent.
(3) Have dive partner attempt to open the air supply valve. Ascend as directed.
c.
Unable to Adjust Air Supply Valve. Control air volume with the exhaust valve. Inform topside of the situation.
2-55
