February 2020
Forward Wing Skin Stiffener

ENGINEERING CHANGE: A change to current serial number drawings onward - non-mandatory - may or may not be published. This change is the result of a product improvement, update or modification. Or a minor change of the design to ease manufacturing, maximize utility, economize materials or ease assembly.

Applies to the Bearhawk Patrol only.
Reference Drawing No. 2

Due to skin deflection in flight (oil canning), a skin stiffener channel has been added 4 inches in front of the main spar web laying on top of the nose ribs. The stiffener is .020 2024-T3 Aluminum, 3/4 inch wide with 5/16 inch flanges.

The stiffener runs from rib 2.5 to rib 13 on the top of the ribs only. Notch flanges of the stiffener 3/4 inch wide at ribs. Rivet to ribs and along channel to skin at approximately 1.5 inch rivet spacing with AN426AD3 or AN426A3 rivets.