Figure 4-26.—Adjustment of bayonet receivers.
Adjustment of Bayonet Receivers
To adjust the bayonet receivers, loosen the two
adjusting screws (fig. 4-26) and rotate the receivers
until the mask fits properly. Retighten the
adjusting screws.
NOTE: Ensure that the top buckles are
tacked down prior to any adjustment.
Adjustment of the bayonet receivers is
performed with the helmet assembly and oxygen
mask assembly donned by the aircrew member.
When properly fitted, the MBU-12/P oxygen
mask can retain a pressure in excess of ambient
pressure up to the maximum pressure supplied by
the regulator.
Maintenance
Proper care and use of oxygen masks is
essential to ensure optimum performance during
routine flight operations and emergencies. The
aircrew member’s responsibility for maintenance
of the oxygen mask is limited to cleaning. Repairs
or other maintenance actions required are
performed at the organizational level or above.
PREFLIGHT/POSTFLIGHT
INSPECTION
The preflight/postflight inspection is a visual
inspection performed by the aircrew member to
4-31
whom the oxygen mask is issued before each
flight. The preflight/postflight inspection consists
of-the following-procedures:
NOTE: Defects or questionable areas
noted during this inspection must be
referred to the proper maintenance activity
for required corrective action.
1. Check the communication system and
microphone for proper installation.
2. Check the mask for damage and proper
operation by using the tester and/or aircraft
oxygen and communications system.
Calendar Inspection
The calendar inspection is conducted every 30
days at the organizational level and consists of
a visual inspection, a functional check, and a
thorough cleaning of the oxygen mask assembly.
Refer to NAVAIR 13-1-6.7 for visual inspection
and functional check procedures.
NOTE: If a discrepancy is noted, refer to
table 4-4 for guidance.
Cleaning Mask
To clean and sanitize the oxygen mask
facepiece and housing assembly, proceed as
follows:
Preferred solution. Make a 1 percent by weight
solution of cleaning compound (Detergent, Gen-
eral Purpose, MIL-D-1 6791, Type I) by adding
1/4 to 1/2 ounce (liquid) of the compound to 1
gallon of water.
CAUTION
WHEN THE FOLLOWING ALTER-
NATE CLEANING SOLUTION MUST
BE USED, ONLY THE LATHER FROM
T H E S O L U T I O N I S U S E D F O R
CLEANING. THIS PREVENTS UN-
DISSOLVED SOAP SOLUTION FROM
GETTING INTO THE VALVE.
Alternate solution. Make a suitable soap
solution by adding approximately 4 tablespoons
of soap powder (P-S-600) to 1 gallon of water.
Hardness of water may require more soap, but
the solution must be sufficiently strong to readily
form lather when agitated. Make sure that all soap
particles are dissolved.
