Midshipman | |Cadet |Cadet |Cadet -------------+-------------+-------------+-------------+------------- Warrant |Warrant |Warrant |Warrant |Warrant Officer |Officer |Officer |Officer |Officer | |Junior Grade |Junior Grade | -------------+-------------+-------------+-------------+------------- Aviation | | |Aviation | Cadet | | |Cadet | -------------+-------------+-------------+-------------+------------- Officers of all the fighting service, whether regular or reserve, take precedence among themselves according to their dates of rank. Officers take command in their respective services in accordance with their dates of rank in the line, the senior, unless otherwise ordered, taking command, whether regular or reserve. The command of a task force or group composed of commands from two or more services devolves upon the senior commanding officer present in the force or group unless otherwise designated by the appropriate common senior, acting for the President. The obvious exceptions to this are that officers outside the line (that is, commissioned in specialized branches or corps) cannot command line organizations. They may, however, in the Army and Air Force, command organizations within the structure of their own corps. Non-rated officers in the Air Force and Navy are not eligible to command tactical flying units. As a specialized case of command, the assigned first pilot and airplane commander of any aircraft continues in command even though a pilot senior in rank may be aboard. Retired officers of the Army rank at the foot of active officers of the same grade; those of the Navy according to date of rank. Changing personnel policies have been reflected by frequent revisions of the scale and grade given noncommissioned leadership. This subject should therefore be checked against current regulations. But as a rough guide, the following can be taken as the corresponding noncommissioned grades and rates in the services: