Abstract: The inlet of a gas turbine is provided with a mechanism for varying the throat area which may be selectively adjusted to maintain the velocity of an incoming air stream at a high level during aircraft takeoff and climbout to thereby reduce forward propagated noise.

Abstract: In a mixed flow gas turbine engine of the type which includes an outer nacelle spaced apart from a core engine to define an annular bypass duct therebetween, a thrust reverse is incorporated into the outer nacelle immediately aft of a fan disposed in the inlet. The thrust reverser reverses the discharge direction of the airflow exhausted from the bypass duct thereby to develop reverse thrust. The unique design and location of the thrust reverser permits the use of an aerodynamically efficient and relatively easy to manufacture cylindrical structure immediately aft of the engine fan frame.