Skin discoloration can be due to changes in melanin. Melanin is a skin pigment that gives color to the skin. Changes in melanin can also cause skin to be patchy. Treatment for skin discoloration includes using topical treatments.
Winglets increase an aircraft's operating efficiency by reducing what is called induced drag at the tips of the wings. An aircraft's wing is shaped to generate negative pressure on the upper surface and positive pressure on the lower surface as the aircraft moves forward.
Tailplane - The flying surface at the aft or tail section of an aircraft used with horizontal or vertical to describe the axis of control or stability. Thickness- Used to describe the total frontal area of an airfoil and generally represented as a percentage of the chord for a given airfoil or wing section.