A shell of a combustor for use in a gas turbine engine , the shell comprising: a combustion liner having an inner surface , an outer surface opposite the inner surface, and a primary aperture extending from the outer surface to the inner surface through the combustion liner; and a heat shield panel having a first surface and a second surface , the inner surface of the combustion liner and the second surface of the heat shield panel defining an impingement cavity therebetween in fluid communication with the primary aperture for cooling the second surface of the heat shield panel; characterised in that the shell further comprises: a particulate capture device attached to the combustion liner , the particulate capture device being configured to capture airflow and particulate in an airflow path (D) proximate the outer surface of the combustion liner, aerodynamically separate the airflow from the particulate, and expel the airflow through the primary aperture towards the second surface of the heat shield panel , wherein the particulate capture device further comprises a collection backstop configured to redirect the airflow to allow for separation of the particulate from the airflow while allowing the particulate to collect at the collection backstop, the collection backstop being located within the particulate capture device. a combustion liner having an inner surface , an outer surface opposite the inner surface, and a primary aperture extending from the outer surface to the inner surface through the combustion liner; and a heat shield panel having a first surface and a second surface , the inner surface of the combustion liner and the second surface of the heat shield panel defining an impingement cavity therebetween in fluid communication with the primary aperture for cooling the second surface of the heat shield panel; characterised in that the shell further comprises: a particulate capture device attached to the combustion liner , the particulate capture device being configured to capture airflow and particulate in an airflow path (D) proximate the outer surface of the combustion liner, aerodynamically separate the airflow from the particulate, and expel the airflow through the primary aperture towards the second surface of the heat shield panel , wherein the particulate capture device further comprises a collection backstop configured to redirect the airflow to allow for separation of the particulate from the airflow while allowing the particulate to collect at the collection backstop, the collection backstop being located within the particulate capture device. a particulate capture device attached to the combustion liner , the particulate capture device being configured to capture airflow and particulate in an airflow path (D) proximate the outer surface of the combustion liner, aerodynamically separate the airflow from the particulate, and expel the airflow through the primary aperture towards the second surface of the heat shield panel , wherein the particulate capture device further comprises a collection backstop configured to redirect the airflow to allow for separation of the particulate from the airflow while allowing the particulate to collect at the collection backstop, the collection backstop being located within the particulate capture device. <EOS>