Abstract: A thrust reverser is disclosed for a turbojet engine having a cowling forming an outer boundary for a gas flow duct, the cowling having at least one reverse thrust opening communicating with the gas flow duct. The thrust reverser includes a thrust reverser door pivotally attached to the cowling so as to move between a forward thrust position, in which the reverse thrust opening is uncovered and the thrust reverser door covers the reverse thrust opening, and a reverse thrust position in which the thrust reverser door directs at least a portion of the gas flow from the duct through the reverse thrust opening. A panel is incorporated into the thrust reverser such that it is movable between a first position in which an inner surface of the panel forms a portion of the outer boundary of the gas flow duct and a second position wherein the entire panel is located within the gas flow duct.