14 CFR § 135.615

Pre-flight. Prior to conducting VFR operations, the pilot in command must—

Determine the minimum safe cruise altitude by evaluating the terrain and obstacles along the planned route of flight;

Identify and document the highest obstacle along the planned route of flight; and

Using the minimum safe cruise altitudes in paragraphs (b)(1)-(2) of this section, determine the minimum required ceiling and visibility to conduct the planned flight by applying the weather minimums appropriate to the class of airspace for the planned flight.

Enroute. While conducting VFR operations, the pilot in command must ensure that all terrain and obstacles along the route of flight are cleared vertically by no less than the following:

300 feet for day operations.

500 feet for night operations.

Rerouting the planned flight path. A pilot in command may deviate from the planned flight path for reasons such as weather conditions or operational considerations. Such deviations do not relieve the pilot in command of the weather requirements or the requirements for terrain and obstacle clearance contained in this part and in part 91 of this chapter. Rerouting, change in destination, or other changes to the planned flight that occur while the helicopter is on the ground at an intermediate stop require evaluation of the new route in accordance with paragraph (a) of this section.

Operations manual. Each certificate holder must document its VFR flight planning procedures in its operations manual.