Jet engine air intake system

An axisymmetric air intake system for a jet aircraft engine comprising a fixed cowl extending outwardly from the face of the engine, a centerbody coaxially disposed within the cowl, and an actuator for axially displacing the centerbody within the cowl. The cowl and centerbody define a main airflow passageway therebetween, the configuration of which is changed by displacement of the centerbody. The centerbody includes a forwardly-located closeable air inlet which communicates with a centerbody auxiliary airflow passageway to provide auxiliary airflow to the engine. In one embodiment, a system for opening and closing the centerbody air inlet is provided by a dual-member centerbody, the forward member of which may be displaced axially with respect to the aft member. The air inlet is open when the forward centerbody member is in a first, rearward position with respect to the aft member. In a second embodiment, the centerbody air inlet may be opened and closed by doors located in the forward wall of a unitary-member centerbody. The air intake system may also be provided with closeable air inlets rearwardly-located in the cowl wall which communicate with cowl auxiliary airflow passageways to provide auxiliary airflow to the engine, either in conjunction with, or independently of, the centerbody auxiliary airflow. In addition, closeable bypass openings are provided which allow control of the normal shock wave within the main airflow passageway.