WANTED

Duration in minutes of oxygen at 100% capacity.

KNOWN

Two man crew plus one passenger, cabin pressure altitude = 15,000 feet, crew masks, normal,

100% capacity.

METHOD

Find "two man crew plus one pass" line, move right then down to 15,000 - "normal" read 232.1

minutes.

WANTED

Duration of oxygen for previous example data at 84% of capacity.

KNOWN

232.1 minutes duration at 100%, 84% capacity, total aircraft low = 13.9 LPM.

METHOD

Multiply 232.1 X 0.84 = 194.9 minutes or multiply 3,226 X 0.84 = 2709.8, divide by 13.9 LPM =

194.9 minutes.

WANTED

Duration of oxygen for complement at other cabin pressure altitude, at less than 100% capacity.

KNOWN

Cylinder at 84% capacity, 100% capacity = 3,226 L, cabin pressure altitude = 21,000 feet. 1 crew

mask = LPM (100%), 1 passenger mask = LPM.

METHOD

Multiply 3,226 L X 0.84 = 2.709.8 L, multiply 2 crew X 7.2 LPM = 14.4 LPM, multiply 1 passenger

X 3.7 LPM, add 14.4 LPM crew plus 3.7 LPM passenger = 18.1 LPM. Divide 3,226 L by 18.1

LPM = 178.2 minutes.

WANTED

Percent of capacity at known pressure and temperature. Pressure when temperature decreases.

KNOWN

Pressure = 1,600 PSIG stabilized cylinder temperature is estimated at 20° C decreased stabilized

cylinder temperature is estimated at -30°C.

METHOD

Enter 1600 PSIG move up to 20° C line, move right to 84%. Move left on 84% line to -30° C line,

move down to 1250 PSIG.

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