7. Difference in altitude
The difference in altitude can be obtained from the
descent rate and the descent time.
Example Obtain the difference in altitude when the
aircraft continues descending for 23 minutes at a
rate of 250 feet per minute.
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 the 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
corresponds to “47” on the outer scale. Thus, the
rate of climb is 470 feet 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 the 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 statute miles into nautical
miles and kilometres.
Answer Align “30” on the outer scale with STAT
(
) on the inner scale.Then, NAUT (
) on the
inner scale corresponds to “26” nautical miles on
the outer scale, and km(s) on the inner scale
corresponds to “48.2” km on the outer scale.
11. Fuel Conversion
Example Convert 16.8 US gallons into litres.
Answer Align “16.8” on the inner scale with U.S
GAL (
) on the outer scale.Then, LITRES (
) on
the outer scale corresponds to “63.5” litres on the
inner scale. (1 U.S. gallon = 3.78541 litres)
The same method can be applied to the
conversions of U.S. gallons
➝
IMP.
gallons / litres
➝
U.S gallons / litres
➝
IMP. gallons
/ IMP. gallons
➝
U.S gallons / IMP. gallons to litres.
12. Volume – weight conversions (fuel pounds to
U.S. gallons, U.K gallons and litres)
Example Convert 13.1 fuel pounds into U.S
gallons, IMP. (imperial) gallons and litres.
(1 fuel pound = 0.167 U.S gallon = 0.139 IMP.
gallon = 0.632 litres.
Answer Align “13.4” on the inner scale with FUEL
LBS (
) on the outer scale.Then, U.S. GAL (
) on
the outer scale corresponds to “21.8( 2.18 U.S.
gallons)” on the inner scale. Then IMP. GAL (
) on
the outer scale corresponds to “18.
2 (1.82 IMP. gallons)” on the inner scale, and
LITRES. (
) on the outer scale corresponds to
“82.7 (8.17 litres)” on the inner scale.
The same method can be applied to the
conversions of U.S gallons
➝
fuel pound, IMP.
gallons, litres / IMP. gallons
➝
fuel pound, U.S.
gallons, litres / litres
➝
fuel pound, IMP. gallons,
U.S. gallons.
13. Volume – weight conversions (oil pounds to
U.S. gallons, U.K gallons and litres)
Example Convert 16.4 oil pounds into U.S
gallons, IMP. (imperial) gallons and litres.
(1 oil pound = 0.133 U.S gallon = 0.111 IMP. gallon
= 0.503 litres.
Answer Align “16.4” on the inner scale with U.S
GAL (
) on the outer scale.Then, U.S. GAL (
) on
the outer scale corresponds to “21.8 (2.18 U.S.
gallons)” on the inner scale. Then IMP. GAL (
) on
the outer scale corresponds to “18.2 (1.82 IMP.
gallons)” on the inner scale, and LITRES. (
) on
the outer scale corresponds to “82.7 (8.17 litres)”
on the inner scale.
The same method can be applied to the
conversions of U.S gallons
➝
oil pound, IMP.
gallons, litres / IMP. gallons
➝
fuel pound, U.S.
gallons, litres / litres
➝
fuel pound, IMP. gallons,
U.S. gallons.
B. General Calculation Functions
1. Multiplication
Example 20 x 15
Answer 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
Answer 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
account the position of the decimal point to obtain
12.5.
3. Proportion
Example 30/20 = 60/x
Answer 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.
