Propeller clearance.

CFR · 2024-01-01 · US · Title 14

Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most adverse center of gravity, and with the propeller in the most adverse pitch position, may not be less than the following: (a) (b) (c) (1) At least one inch radial clearance between the blade tips and the airplane structure, plus any additional radial clearance necessary to prevent harmful vibration; (2) At least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts of the airplane; and (3) Positive clearance between other rotating parts of the propeller or spinner and stationary parts of the airplane.

official document · source cfr-2024 · id 14:§ 25.925