Definition
An instructor failing in professional duty by personally demonstrating, while flying with a student, actions that violate regulations, safe operating practices, or good judgment — such as buzzing, showing off, skipping checklists, or accepting marginal weather. Listed in the Aviation Instructor's Handbook as one of the 'Instructor Don'ts' because students learn at least as much from what an instructor does as from what an instructor says.
Plain English
When an instructor shows a student bad or unsafe flying habits by doing them in the airplane. Students copy what their instructor does, so an instructor who flies carelessly teaches the student to fly carelessly.
Context Anchor
Seen in instructor professionalism guidance, especially in lists of behaviors aviation instructors should avoid.
Derivation
Model' here means 'to set an example of' — the same sense as a role model. So 'modeling' a behavior means showing it in a way others will copy. The phrase warns instructors that their actions become the student's template, whether intended or not.
Why Pilots Care
Students copy what instructors do; demonstrating poor practices can create unsafe habits that affect safety and judgment.
Intuition Check
Do not read model here as building a model airplane or formally teaching a maneuver. It means setting an example through your own behavior, even when you did not intend the student to copy it.
Example Sentence 1
The chief instructor reminded the new CFIs that low passes over a friend's house, even on a repositioning flight, model irresponsible flight behaviors and undermine everything taught in the classroom.
Example Sentence 2
Choosing not to model irresponsible flight behaviors helps the instructor build safe habits in every student.