Abstract: A thrust reverser for a turbofan jet engine having a stationary structure defining an upstream part of a fan cowling and an axially displaceable, annular structure located downstream of the stationary structure, wherein the inner surface of the fan cowling is spaced from an outer surface of an engine cowling to form an annular duct. A plurality of flaps form a portion of the inner surface of the fan cowling during a forward thrust position, and in a reverse thrust position, the flaps pivotably rotate about a stationary pivot so that their first edges are adjacent with the outer surface of the engine cowling to block the annular duct. A plurality of thrust reverser baffle portions are covered by the flaps during the forward thrust position, and during the reverse thrust position, the thrust reverser baffle portions cover a passageway in the fan cowling between the stationary structure and the displaceable structure.