Continuous approach according to below graph is recommended to be used,
when approaching airports where no ATC restrictions exists and
in weather conditions in which a straight in approach can be expected.
The profile is based on idle power until landing configration and
a descend rate of 1000 ft / 3 Nm. Vertical speed formulas to use:
ground speed/2 x 10 (ex. GS 160 kts = 160 / 2 x 10 = 800 ft / min)