Definition
A section of Title 14 of the Code of Federal Regulations (14 CFR Part 121) that sets the dispatch and flight release weather requirements for Part 121 air carriers. It states that no person may dispatch or release an aircraft to a destination airport unless the appropriate weather reports or forecasts, or any combination thereof, indicate that the weather conditions will be at or above the authorized minimums at the estimated time of arrival.
Plain English
A federal rule that says an airline flight cannot be released for departure unless the forecast shows the destination weather will be good enough to land when the flight gets there.
Context Anchor
Seen in discussions of weather requirements for Part 121 operators, especially when deciding whether a scheduled air carrier flight may be released to its destination.
Derivation
The § symbol means 'section' and comes from Latin signum sectionis. The number 121.613 identifies Part 121 (Operating Requirements: Domestic, Flag, and Supplemental Operations), Subpart U, Section 613. Knowing this helps you find and cite the rule quickly.
Why Pilots Care
It prevents dispatch into weather that could prevent a safe landing, directly affecting go/no-go decisions for Part 121 operations.
Intuition Check
Do not read § 121.613 as a weather report or a minimum by itself. It is a rule reference that tells you when the weather forecast is good enough for a Part 121 flight release.
Example Sentence 1
Under § 121.613, the dispatcher could not release the flight to Denver because the forecast showed conditions below landing minimums at the estimated time of arrival.
Example Sentence 2
Under § 121.613 the captain confirmed alternate airport weather met the required minima prior to departure.