B5-22 PREPARATION OF CHARTS 
c. From the surface to termination of flight 4km with (a) and 
(b) satisfied. 
COMBINATION MISSING AND DOUBTFUL TEMPERATURE 
The limits set for missing temperature will be followed, and the 
doubtful temperature portion weighted 1/2 that of the missing tem- 
perature. Example: 
Missing temperature from 950 to 900 mb (500m), doubtful 
temperature from 620 to 580 mb(1/2 600m), missing temper- 
ature from 430 to 416 mb (280m); (500+ 300 + 280) m = 1.080 
km. (Altitude data considered doubtful beginning at 430 mb.) 
10.3 Beginning of Doubtful Altitude. The doubtful portion will begin at 
the base of the first stratum within which the limits indicated in §B5-10.2 
are exceeded and continue through the remainder of the flight. 
11. Completing Constant Pressure Data Blocks. Blocks for entering 
constant pressure level data are printed to the right of the adiabatic 
chart on WBAN-31( ). All stations will enter data in the blocks corres- 
ponding to the constant pressure levels that are printed on the WBAN- 
31( ). Data will be entered in the CPD blocks in accordance with the key 
printed on WBAN-31( ). Entry will be made at any level for which data 
are available regardless of whether data are available at other levels. 
a. Entries in the CPD block for the surface level will consist of 
pressure in whole millibars, temperature, relative humidity, 
dewpoint depression, and wind direction and speed. A compu- 
tation block is provided to enter the dewpoint. Additional blocks 
are provided to code the data for transmission. 
b. When the surface pressure is less than 1000.0or 850.0 milli- 
bars, the altitude of these levels will be computed on the 
back of WBAN-31A in accordance with J§B5-8. The values 
to the nearest whole geopotential meter willbe entered in ap- 
propriate spaces in the CPD blocks, and dashes will be en- 
tered in the spaces provided for temperature, relative hu- 
midity, dewpoint depression, and wind, direction and speed. 
c. Altitude, temperature, relative humidity, and wind data atthe 
corresponding constant-pressure levels willbe taken from the 
adiabatic chart and the winds aloft graphing board and entered 
in the appropriate section of the constant pressure data block. 
This may be accomplished while the raobis still in progress. 
Lo 1a68) FMH#3 
