Abstract: An afterburn device for a turbojet engine comprises a flame arrester formed by a plurality of radial arms distributed evenly around the rotational axis of the engine at the upstream end of the afterburn chamber. Each arm consists of a fixed rear part, and a front part which is separable from the rear part in a circumferential direction along a median joint plane, the front parts being carried on a ring which is rotatably mounted on the outer casing of the engine. Drive means is provided for rotating the ring between a first position for dry operation, and a second position for afterburn operation. In the first position the front and rear parts of the arms are aligned and joined to provide the arms with a streamlined, low-drag, zero angle of incidence profile suitable for dry operation.