TM 55-1510-221-10
Table 2-4. Oxygen Flow Planning Rates vs Altitude
(All Flows In LPM Per Mask At NTPD)
CABIN PRESSURE
CREW MASK
CREW MASK
PASSENGER
ALTITUDE IN FEET
NORMAL
100%
MASK
(DILUTER
(1)
DEMAND)
(1)
3 1,000
-0-( 2)
4.2
3.7 (3)
30,000
-0-( 2)
4.4
3.7 (3)
29,000
-0-( 2)
4.7
3.7 (3)
28,000
-0-( 2)
5.0
3.7 (3)
27,000
-0-( 2)
5.3
3.7 (3)
26,000
-0-( 2)
5.6
3.7 (3)
25,000
-0-( 2)
5.9
3.7
24,000
-0-( 2)
6.2
3.7
23,000
-0-( 2)
6.6
3.7
22,000
-0-( 2)
6.9
3.7
2 1 ,000
-0-( 2)
7.2
3.7
20,000
3.6
7.6
3.7
19,000
3.9
7.9
3.7
18,000
4.2
8.3
3.7
17,000
4.5
8.7
3.7
16,000
4.8
9.1
3.7
15,000
5.1
9.5
3.7
14,000
5.4
10.0
3.7
13,000
5.8
10.4
3.7
12,000
6.1
10.9
3.7
11,000
6.5
11.3
3.7
10,000
6.9
11.9
3.7
NOTES:
(1) Based on minute volume of 20 LPM-BTPS (Body Temperature and Pressure Saturated).
(2) Use 100% oxygen at or above 20,000 feet.
(3) Not recommended for other than emergency descent use above 25,000 feet.
If average climb or descent flows are desired, add the values between altitudes and divide by the number
of values used.
For example, to determine the average rate for a uniform descent between 25,000 feet and 15,000 feet
perform the following.
(5.9 + 6.2 + 6.6 + 6.9 + 7.2 + 7.6 + 3.9 + 4.2 + 4.5 + 4.8 + 5.1) ÷ 11 = 5.7 LPM
This method is preferred over averaging the extremes an some flow characteristics vary in such a way as
to yield as incorrect answer.
2-48
