Definition
An FAA aviation safety inspector assigned as the primary point of contact and oversight authority for a specific certificate holder, such as an air carrier, repair station, or training organization. The Principal Inspector is responsible for surveillance, certification actions, and approval of operational documents within their assigned discipline (operations, maintenance, or avionics).
Plain English
The FAA inspector personally responsible for keeping an eye on a particular airline, flight school, or repair shop and approving how it operates.
Context Anchor
You may see PI in FAA manuals, approval documents, inspection records, or discussions about who has FAA oversight responsibility for an operation.
Derivation
‘Principal’ comes from the Latin principalis, meaning ‘first’ or ‘chief.’ In FAA usage it marks the lead inspector for a certificate holder — the one whose decisions and signatures carry weight on that operator's authorizations.
Why Pilots Care
Operators and pilots coordinate directly with their PI for procedure approvals, compliance questions, and inspection findings that affect flight operations.
Intuition Check
Principal does not mean a school principal here. It means the primary or lead FAA inspector assigned to that oversight job.
Example Sentence 1
The airline submitted its revised training curriculum to the Principal Inspector for approval before rollout.
Example Sentence 2
Pilots submitted their training records to the PI as part of the annual audit.