The tailplane comprises the tail-mounted fixed horizontal stabiliser and movable elevator. The fin comprises the fixed vertical stabiliser and rudder. Front suspension Independent damper strut with anti-dive geometry and stabiliser bar. The wings are fitted with underwing stabiliser floats. It is also used as a humectant, stabiliser, and thickening agent. A rotary wing is typically unstable in yaw, requiring a vertical stabiliser. Sodium cromoglycate was the first clinically utilised mast cell stabiliser. It's 'HO' specification included upgraded suspension components such as front and rear stabiliser bars. It has a horizontal stabiliser in a T-tail configuration and a retractable tricycle landing gear. The rear section is called the elevator, and is usually hinged to the horizontal stabiliser. It had a common fuselage cross-section with the A330 and also a new horizontal stabiliser. The only difference consisted of rear stabiliser bars now fitted to all sedans. To compensate for the reduced moment arm, it has a larger vertical stabiliser. It is also used as a stabiliser in the manufacture of the propellant Cordite. This allowed longitudinal trim in the absence of a separate horizontal stabiliser.