Chine (aeronautics)

[note 1] In a flying boat hull or floatplane float, the longitudinal line of sharp change in cross-section where the bottom plane meets the sidewall is an example of a chine.

Large chines along the forward fuselage can have a significant effect on aircraft lift, drag, longitudinal balance and directional stability.

Unlike a conventional fuselage, the chines allow the crossflow to travel smoothly over their profile and beyond, avoiding the side forces due to flow separation and stagnation.

The improved crossflow behaviour also benefits lateral characteristics by reducing yaw-induced roll, especially during landing and takeoff of delta-winged aircraft.

[5] This has led fifth-generation jet fighter designs to replace low-stealth canard surfaces with chines, when helping to generate vortex lift over the main wings.