http://slideplayer.com/3621102/13/images/13/The+thrust+reverser+is%2C+essentially%2C+a+pair+of+clamshell+doors+mounted+at+the+rear+of+the+engine+which%2C+when+deployed%2C+divert+thrust+normal+to+the+jet+engine+flow+to+help+slow+an+aircraft+upon+landing..jpg