Nav. Computer: Put
100 (sm) next to stat.m. index and read distance next to naut.m.
index: 86.5nm.
Put 20 (minutes) on inner
scale next to 86.5 (nm) on outer scale; groundspeed 260 kts
(on outer scale next to 60 on inner scale).
Go to 215 (nm) on outer
scale and read time in minutes on inner scale: 49.5 minutes.
Calculator: 100x5280÷6080
= 86.84 nm÷20x60 = 260.5 kts, 215÷260.5 = 0.825 hr,
0.825x60 = 49.52 minutes.