Definition
A specific paragraph within Title 14 of the Code of Federal Regulations, Part 23 (Airworthiness Standards: Normal Category Airplanes), Section 23.2135, paragraph (c). Section 23.2135 sets the controllability requirements an airplane must meet to be certificated, and paragraph (c) addresses controllability requirements related to trim, stability, and the airplane's behavior in specified flight conditions.
Plain English
It is one small lettered paragraph inside the federal rules that say what an airplane must be able to do to be approved for flight. The number tells you exactly where to find it: Title 14, Part 23, Section 23.2135, paragraph (c).
Context Anchor
Seen in Federal Aviation Administration handbooks and training material when a statement is tied to the airplane certification rules, especially in discussions of controllability and maneuvering speed.
Derivation
CFR stands for Code of Federal Regulations -- the organized collection of rules issued by U.S. federal agencies. Title 14 covers Aeronautics and Space. Part 23 covers airworthiness standards for normal category airplanes. The numbers and lowercase letter simply pinpoint the exact paragraph, the way a chapter, section, and subsection number locate a passage in a book.
Why Pilots Care
Ensures the aircraft design meets minimum federal standards for safe control immediately after liftoff, directly affecting training and operational safety margins.
Grounding Statement
Think of it as a street address for one paragraph in the federal aviation rules.
Intuition Check
Do not read this as an airspeed, maneuver, or cockpit procedure. It is a reference to a specific paragraph in the aviation regulations.
Example Sentence 1
The handbook references 14 CFR part 23, section 23.2135(c) when explaining the controllability standards a normal category airplane must meet.
Example Sentence 2
During the preflight briefing the instructor noted that the trainer airplane had been certified to 14 CFR part 23, section 23.2135(c), giving the student confidence in its handling right after rotation.