FAR 1.3 — Rules of Construction

FAR 1.3 is the FAA's instruction manual for reading the rest of the regulations. It tells you how to interpret the words you'll see throughout Title 14 of the CFR. While it isn't an operational rule you'll fly by, understanding it keeps you from misreading a regulation that actually does affect your flying.

Key points:

• Singular and plural are interchangeable. A rule that says 'aircraft' applies whether you have one airplane or several, and vice versa.
• Masculine includes feminine. Gendered language in older regulations applies equally to all pilots.
• 'Shall' is mandatory — it means you must do the thing.
• 'May' is permissive — it grants authority or permission. Phrases like 'no person may' or 'a person may not' mean the action is prohibited: no one is authorized or permitted to do it.
• 'Includes' means 'includes but is not limited to.' A list following 'includes' is illustrative, not exhaustive — other items can still fall under the rule.

Operationally, this matters when you're parsing a regulation on a checkride or in the cockpit and need to know whether something is required, optional, or merely an example.