Gas turbine engine propulsion systems for modern aircraft often include an under-wing mounted engine and nacelle including a thrust reverser. The thrust reverser selectively redirects the flow of air from the fan duct through the nacelle in order to apply a reverse thrust to the aircraft, which is used during landing to slow or backup the aircraft. One style of thrust reverser includes a translating sleeve. The translating sleeve translates aft to deploy blocker doors into the bypass air duct of a nacelle. The blocker doors redirect air in the bypass air duct outward though a series of cascades which then turn the air in a pattern, primarily forward, producing reverse thrust.
In cases where the moving parts of the thrust reverser, including the translating sleeve, should not contact, during aircraft operation, any portion of the wing to which the thrust reverser is relatively closely positioned. In the aircraft's design, where the spacing between the thrust reverser and the wing is set to ensure there is no unintentional contact. However, close spacing of the thrust reverser and propulsion system to the wing can be important for optimizing various design goals, thus, there is an incentive to spacing the two as close together as possible while still eliminating all clashes. Recently, there has been interest in increasing a nacelle's bypass ratio, which is the ratio of air that travels through the bypass duct to the total air taken into a nacelle inlet. Higher bypass ratio engines usually result in larger diameter propulsion systems, which make the problem of packaging the propulsion system relative to the wing more acute. If a high bypass ratio propulsion system cannot be positioned relatively close to the wing, then the space required to accommodate its larger diameter will require taller and heavier landing gear to hold the aircraft higher off the ground (among other negative design consequences). Thus, there is a need for a thrust reverser design that facilitates close positioning of the propulsion system to the wing while still eliminating any unintentional aircraft wing slat-nacelle contact.