A cowl door (34; 36) comprising: a cowl door body having a first side, a second side, and an interior surface and an exterior surface extending between the first side and the second side, the cowl door body configured to be rotatably mounted to a structure (24; 32) at the first side of the cowl door body; at least one stiffener mounted to the interior surface of the cowl door body and extending lengthwise at least a portion of a distance between the first side and the second side of the cowl door body, the at least one stiffener comprising a stiffener body comprising a latch housing section disposed at a second stiffener end of the stiffener body proximate the second side of the cowl door body; and a latch member mounted to the stiffener body and disposed at least partially within the latch housing section of the stiffener body, wherein the at least one stiffener is configured as a hoop stiffener, wherein the stiffener body further comprises a mount portion mounted to the interior surface of the cowl door body and a hoop portion projecting outward from the mount portion, wherein the stiffener body has a first stiffener end opposite the second stiffener end, characterised in that the stiffener body further comprises a support section that extends from the first stiffener end a portion of a length of the stiffener body and the latch housing section extends from the second stiffener end another portion of the length of the stiffener body, and wherein the hoop portion of the stiffener body has a first width at the latch housing section and a second width at the support section, different than the first width. a cowl door body having a first side, a second side, and an interior surface and an exterior surface extending between the first side and the second side, the cowl door body configured to be rotatably mounted to a structure (24; 32) at the first side of the cowl door body; at least one stiffener mounted to the interior surface of the cowl door body and extending lengthwise at least a portion of a distance between the first side and the second side of the cowl door body, the at least one stiffener comprising a stiffener body comprising a latch housing section disposed at a second stiffener end of the stiffener body proximate the second side of the cowl door body; and a latch member mounted to the stiffener body and disposed at least partially within the latch housing section of the stiffener body, wherein the at least one stiffener is configured as a hoop stiffener, wherein the stiffener body further comprises a mount portion mounted to the interior surface of the cowl door body and a hoop portion projecting outward from the mount portion, wherein the stiffener body has a first stiffener end opposite the second stiffener end, characterised in that the stiffener body further comprises a support section that extends from the first stiffener end a portion of a length of the stiffener body and the latch housing section extends from the second stiffener end another portion of the length of the stiffener body, and wherein the hoop portion of the stiffener body has a first width at the latch housing section and a second width at the support section, different than the first width.