<P> A few organizations within the army maintain authorizations for a chief warrant officer to serve as an XO / 2IC . One example of this is the Modular Ammunition Platoon, where the ammunition technician acts as the second - in - command during the absence of the platoon leader . While the experience gained as an XO is highly beneficial for an army officer's professional development, it is not necessarily a prerequisite for a command position . At the army level of command, a commanding general will have a deputy commanding general as second in command and an "executive officer" on his personal staff who works as his liaison to the general staff and an aide - de-camp who takes care of his calendar and personal needs . </P> <P> The executive officer is the billet of the officer who is second - in - command at the company / battery, battalion / squadron, and Marine Expeditionary Unit (MEU) / regiment / aviation group (i.e., Marine Aircraft Group, Marine Air Control Group, and Marine Wing Support Group) level . Per the Marine Corps Manual, paragraph 1007.5: "The executive officer shall be an officer of the organization who is eligible to succeed to command, and normally will be the officer next in rank to the commander . As the direct representative of the commander, all orders issued by the executive officer shall have the same force and effect as though issued by the commander . The executive officer shall conform to and effectuate the policies and orders of the commander and shall be prepared to assume command at any time the need should arise ." At higher levels of command, the second - in - command is the assistant division / wing commander or, in the case of a Marine Expeditionary Force (MEF), deputy commander . For those commands having a general officer (usually a brigadier general) in command without a designated assistant commander or deputy commander, such as a Marine Expeditionary Brigade (MEB) or Marine Logistics Group (MLG), the chief of staff (a colonel) is the second - in - command . Unlike their U.S. Navy counterparts, XOs of U.S. Marine Corps squadrons in U.S. Naval Aviation do not "fleet up" to become CO . </P> <P> An XO is assigned to all ships, aviation squadrons, and shore units and installations, and is responsible to the captain for all ship's work, drills, exercises, personnel organization, and the policing and inspection of the ship . When the ship goes to action stations, the XO confirms that the ship actually is ready for combat and reports this to the captain . The XO's own action station is in a separate part of the ship from that of the captain, so that a single hit will not likely incapacitate both officers . On small ships with no first lieutenant, gunnery officer, or navigator, the executive officer may also be responsible for the duties of those officers . Carrier air wings in the U.S. Navy do not have an XO, but have a deputy commander (DCAG) instead; for shore - based or functional naval air wings, the equivalent position is the deputy commodore . </P> <P> In the U.S. Coast Guard, on board small cutters and patrol boats that are commanded by either a junior officer or a senior enlisted member, executive chief petty officers or executive petty officers are usually assigned to serve as second - in - command . </P>

Who was responsible for serving as the assistant to the regimental adjutant