Aircraft engine cowling with reduced gap

The engine has an air inlet structure (6) fixed to a fan casing (5), and a fan cover (7) and a thrust reverser cowl. A rod (48) and rigidifying complementary units (58, 60) are placed in the structure or between the cover and the cowl. The rod and units are placed to limit clearance between the cover and cowl, in spite of differences of pressure applied on the structure due to aerodynamic flow of the air.