51
50
B. General Calculation Functions
1) Multiplication
Example:
20
M
15
Operation:
Align “20” on the outer scale with “10” on the inner scale. Then, “15” on the
inner scale corresponds to “30” on the outer scale. Take into account the
position of the decimal point and add one zero to obtain 300. Note that with the
scales of this watch, the position of the decimal point cannot be obtained.
2) Division
Example:
250 / 20
Operation:
Align “25” on the outer scale with “20” on the inner scale. Then, “10” on the
inner scale corresponds to “12.5” on the outer scale. Take into eccount the
position of the decimal point to obtain 12.5.
3) Proportion
Example:
30/20 = 60/x
Operation:
Align “30” on the outer scale with “20” on the inner scale. Then, “60” on the
outer scale corresponds to “40” on the inner scale. At this point,the proportion
for every value on the inner and outer scales is 30:20.
4) Square root
Example:
Square root of 225
Operation:
Turn the outer scale showly and find a value that corresponds to both “22.5” on
the outer scale and “10” on the inner scale. In this example, “22.5” on the outer
scale corresponds to “15” on the inner scale, and “10” on the inner scale
corresponds to “15” on the outer scale. Thus, the answer is 15.
Answer.
Align “25” on the outer scale with “10” on the inner scale. Then, “23” on the inner
scale corresponds to “57.5” on the outer scale. Thus, the difference in altitude is
5,750 feet.
8) Rate of climb (or descent)
The rate of climb (or descent) can be obtained from the time required to reach an altitude.
Example:
Obtain the rate of climb when an aircraft reaches an altitude of 7,500 feet after
climbing for 16 minutes.
Answer.
Align “75” on the outer scale with “16” on the inner scale. Then, “10” on the inner
scale correspons to “47” on the outer scale. Thus, the rate of climb is 470 per
minute.
9) Time of climb (or descent)
The time required for climb can be obtained from the altitude to be reached and the rate of
climb (or descent).
Example:
Obtain the time of climb when an aircraft is to climb to 6,300 feet at a rate of 550
feet per minute.
Answer.
Align “55” on the outer scale with “10” on the inner scale. Then, “63” on the
outer scale corresponds to “11.5” on the inner scale. thus, the time of climb is 11
minutes and 30 seconds.
10) Conversion
Example:
Convert 30 statuts miles into nautical miles and kilometers.
Operation:
Align “30” on the outer scale with STAT (
Y
) on the inner scale. Then, NAUT
(
Y
) on the inner scale corresponds to “26” nautical miles on the outer scale,
and “12 km” (s) on the inner scale corresponds to “48.2” km on the outer scale.
