Except while holding in a holding pattern of 2 minutes or less, or
while turning, each person operating an aircraft under VFR in level
cruising flight more than 3,000 feet above the surface shall maintain the
appropriate altitude or flight level prescribed below, unless otherwise
authorized by ATC:

(a) When operating below 18,000 feet MSL and --

(1) On a magnetic course of zero degrees through 179 degrees, any odd
thousand foot MSL altitude +500 feet (such as 3,500, 5,500, or 7,500); or

(2) On a magnetic course of 180 degrees through 359 degrees, any even
thousand foot MSL altitude +500 feet (such as 4,500, 6,500, or 8,500).

(b) When operating above 18,000 feet MSL to flight level 290
(inclusive) and --

(1) On a magnetic course of zero degrees through 179 degrees, any odd
flight level +500 feet (such as 195, 215, or 235); or

(2) On a magnetic course of 180 degrees through 359 degrees, any even
flight level +500 feet (such as 185, 205, or 225).

(c) When operating above flight level 290 and --

(1) On a magnetic course of zero degrees through 179 degrees, any
flight level, at 4,000-foot intervals, beginning at and including flight
level 300 (such as flight level 300, 340, or 380); or

(2) On a magnetic course of 180 degrees through 359 degrees, any flight
level, at 4,000-foot intervals, beginning at and including flight level
320 (such as flight level 320, 360, or 400).