Executive officer An executive officer is generally a person responsible for running an organization , although the exact nature of the role varies depending on the organization . Administrative law . While there is no clear line between executive or principal and inferior officers , principal officers are high - level officials in the executive branch of U . S . government such as department heads of independent agencies . In " Humphrey ' s Executor v . United States " , 295 U . S . 602 ( 1935 ) , the Court distinguished between executive officers and quasi - legislative or quasi - judicial officers by stating that the former serve at the pleasure of the president and may be removed at his discretion . The latter may be removed only with procedures consistent with statutory conditions enacted by Congress . The decision by the Court was that the Federal Trade Commission was a quasi - legislative body because of other powers it had , and therefore the president could not fire an FTC member for political reasons . Congress can ’ t retain removal power over officials with executive function ( " Bowsher v . Synar " ) . However , statutes can restrict removal if not purely executive ( " Humphrey " ’ s executor ) , but can ' t restrict removal of purely executive officer ( " Myers v . United States , " 272 U . S . 52 ( 1926 ) ) . The standard is whether restriction " impedes the president ’ s ability to perform his constitutional duty " ( " Morrison v . Olson " , 487 U . S . 654 ( 1988 ) ) . Corporate law and other legal associations . In business , the executive officers are the top officers of a corporation , the chief executive officer ( CEO ) being the best - known type . The definition varies ; for instance , the California Corporate Disclosure Act defines " executive officers " as the five most highly - compensated officers not also sitting on the board of directors . In many insurance policies , executive officer means , in the case of a corporation , any chairman , chief executive officer , chief financial officer , chief operating officer , president , or general counsel . In the case of a sole proprietorship , an executive officer is the sole proprietor . In the case of a partnership , an executive officer is a managing partner , senior partner , or administrative partner . In the case of a limited liability company , an executive officer is any member , manager , or officer . In the airline industry , the executive officer , more commonly known as the first officer , is the second in command of the aircraft . In a fixed wing aircraft the first officer sits in the right - hand seat but a rotary wing aircraft they sit on the left . Military . In the units of some military force s , typically those that are naval in nature , the executive officer ( XO ) is the second - in - command , reporting to the commanding officer ( CO ) . United Kingdom . The term is not used in the British Army or Royal Marines ( RM ) , in which the designation second - in - command ( 2i / c ) is used as a formal appointment . In the Royal Air Force ( RAF ) , the term is informally used between officers and airmen , referring to the officer who is second - in - command . It is formally used in the Royal Navy ( RN ) , however . In smaller vessels , such as submarine s and frigate s , the executive officer also holds the position of first lieutenant . Originally , the second - in - command was usually referred to as first lieutenant ( or as " number one " ) , although it is becoming more common to hear the term XO . On larger ships , in which the XO holds the rank of commander , the XO is usually referred to simply as " the commander " . The XO heads the executive department . United States . In the United States Army and Marine Corps , for example , there are XO billet s in each company , battalion , and brigade , though generally not at higher levels of command until the army level of command . The XO billet is not a command ; rather it is considered staff . The XO is typically responsible for the management of day - to - day activities , such as maintenance and logistics , freeing the unit commander to concentrate on tactical planning and execution . The XO also takes charge in the absence of the Commanding Officer . While the experience gained as an XO is highly beneficial for an officer ' s professional development , it is not necessarily a prerequisite for a command position . At the army level of command , a General will have a Deputy Commander 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 . In the United States Navy and Coast Guard , XOs are normally assigned to all ships and shore units , and have a similar role to their counterparts in the Army and Marine Corps . On board Coast Guard cutters that are commanded by either a junior officer or a senior enlisted member , executive petty officer s ( XPOs ) are usually assigned to serve as second - in - command . The United States Air Force ( USAF ) uses the titles of " vice commander " ( CV ) , or " deputy commander " ( DC ) for an officer who serves as the second - in - command for an organization above squadron level . For a squadron , the second - in - command is typically termed the " director of operations " or " operations officer " ( DO ) . The term " executive officer " is used to designate an officer who serves as an administrative assistant to a senior officer . In the other uniformed services , this position is usually called an " executive assistant " or " aide - de - camp . " The rank of an executive officer can vary from lieutenant ( working for a colonel ) to a colonel ( serving as the executive officer to the Chief of Staff of the Air Force . ) A unique application of the term is executive officer to the Supreme Allied Commander Europe , and commander , United States European Command . This position is typically held by a brigadier general or rear admiral ( LH ) and is drawn from all of the armed services . The duties involve serving as both an " executive assistant " to Supreme Allied Commander Europe ( SACEUR ) and also includes command responsibilities for the U . S . military community at Supreme Headquarters Allied Powers Europe ( SHAPE ) in Belgium .