form of fig1 and 16 at least the second panel 235 is pivotably mounted on the outer skin 31 a of the moving cowl 31 around an axis u03b4 substantially parallel to the axis u03b4 of the nacelle and that panel is opened toward the inside of the sliding cowl 31 when the latter goes from its normal position fig1 to its thrust reversal position fig1 as shown in fig1 and 18 the opening of the panel 235 toward the inside of the sliding cowl 31 may be obtained by suitable guiding of that panel using the rail r secured to the beam p that is located at the top of the nacelle and which enables the connection thereof with the pylon 14 more specifically as shown in fig1 this rail r may be inclined with respect to the primary r 1 and secondary r 2 rails in which the outer 31 a and inner 31 b skins of the moving cowl 31 slide respectively or may assume any suitable shape like that shown in fig1 a making it possible to optimize the desired flows of air in the alternatives shown in fig1 to 25 the panel 235 is no longer guided by a rail but by a simple border b secured to the beam p against which it is elastically recalled a strip of material with a low friction coefficient such as teflon.