(a) No person may operate a civil aircraft in IFR conditions unless it
carries enough fuel (considering weather reports and forecasts and weather
conditions) to --
(1) Complete the flight to the first airport of intended landing;
(2) Except as provided in paragraph (b) of this section, fly from that
airport to the alternate airport; and
(3) Fly after that for 45 minutes at normal cruising speed or, for
helicopters, fly after that for 30 minutes at normal cruising speed.
(b) Paragraph (a)(2) of this section does not apply if:
(1) Part 97 of this chapter prescribes a standard instrument approach
procedure to, or a special instrument approach procedure has been issued
by the Administrator to the operator for, the first airport of intended
landing; and
(2) Appropriate weather reports or weather forecasts, or a combination
of them, indicate the following:
(i) For aircraft other than helicopters. For at least 1 hour
before and for 1 hour after the estimated time of arrival, the ceiling
will be at least 2,000 feet above the airport elevation and the visibility
will be at least 3 statute miles.
(ii) For helicopters. At the estimated time of arrival and for 1
hour after the estimated time of arrival, the ceiling will be at least
1,000 feet above the airport elevation, or at least 400 feet above the
lowest applicable approach minima, whichever is higher, and the visibility
will be at least 2 statute miles.