TM 5-1940-321-13&P
b. Inflate Keel.
CAUTION
Do not operate the f530 IAB with an underinflated keel. Under-inflation can
result in failure of the transom and thrustboard attachment and reduced
performance. Correct inflation pressure for the keel is 220 to 240 mb (3.2 to
3.5 psi).
( 1 ) Move to the bow section inside of the craft. The keel is the inflatable structure
along the bottom of the craft (under the floorboards).
( 2 ) Locate the keel metal valve cap and insert. On a new craft, the valve cap and
insert are normally not installed on the valve base. They are in a storage pouch
near the valve that is located just forward of the thrustboard. Screw the valve
insert firmly into the keel valve (the metal valve cap must be removed).
( 3 ) Verify that the keel is centered in the craft. Insert the foot pump hose and pump
smoothly until the pump becomes difficult to operate.
( 4 ) Remove the foot pump hose and insert the pressure gauge in the valve.
Observe the pressure. The correct keel pressure is 220 to 240 mb (3.2 to 3.5
psi)
( 5 ) Add or release air to achieve correct air pressure. To release air from the keel,
unscrew the metal valve insert approximately 1/2 turn. With the pressure gauge
inserted in the valve, monitor the pressure gauge reading.
( 6 ) When pressure is correct, screw in the metal valve insert, remove the pressure
gauge, and screw the metal valve cap onto the valve. Tighten the metal valve
cap and metal valve insert firmly by hand.
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