Helmet airflow control member and helmet

A helmet, comprising:

• a shell;
• and
• a helmet airflow control member including
• a plate-like main body arranged on the shell and including a main body rear surface that covers part of a shell outer surface, and
• at least one passage formation portion arranged on the main body rear surface, wherein
• a periphery of the main body rear surface includes a first peripheral portion, which is shaped in correspondence with the shell outer surface and closes a space between the main body rear surface and the shell outer surface, and a second peripheral portion, which is spaced apart from the shell outer surface and defines an opening of the space between the main body rear surface and the shell outer surface in cooperation with the shell outer surface, and
• the passage formation portion defines at least part of a passage in the space, with the passage extending from the opening into the space and returning from the space to the opening.

A helmet airflow control member, comprising:

• a plate-like main body arranged on a shell and including a main body rear surface that covers part of a shell outer surface;
• and
• at least one passage formation portion arranged on the main body rear surface, wherein
• a periphery of the main body rear surface includes
• a first peripheral portion that is shaped in correspondence with the shell outer surface and closes a space between the main body rear surface and the shell outer surface, and
• a second peripheral portion that is spaced apart from the shell outer surface and defines an opening of the space between the main body rear surface and the shell outer surface in cooperation with the shell outer surface, and
• the at least one passage formation portion includes
• at least one first passage formation portion that defines a first passage extending from the opening into the space and returning from the space to the opening, and
• at least one second passage formation portion that is located adjacent to the at least one first passage formation portion to define a second passage extending from the space toward the opening and connected to a hole extending through the shell.