an aircraft squadron; otherwise, women are prohibited from serving on board combatant vessels. This   law   allows   women   to   be   permanently assigned   to   designated   ships   such   as   tenders, transports,  hospital  ships,  and  vessels  of  a  similar classification.  It also allows women to be temporarily assigned to any  naval vessel or aircraft squadron for up to 180 days provided the ship or squadron is not expected to be assigned to a combat mission. DUTY DEFINITIONS The  following  definitions  will  assist  you  in understanding the types of duty to which women may be assigned: 1.   Combat   mission. A  combat   mission   is   a mission of an individual unit, ship, or aircraft whose primary  objective,  individually  or  collectively  as  a naval  task  organization,  is  to  seek  out,  reconnoiter, and engage an enemy. 2.   Risk  rule.    The  risk  rule  is  the  criteria  upon which noncombat positions are closed to women.  It is based  upon  the  risks  of  direct  combat,  exposure  to hostile  fire,  and  capture  when  the  type,  degree,  and duration of such risks are equal to or greater than the combat units with which they are normally associated within a given theater of operation. 3.   Temporary  duty.    Temporary  duty  (TEMDU) orders  are  orders  that  involve  detachment  from  one station  and  assignment  to  another  station  or  stations for  TEMDU  pending  further  assignment  to  a  new permanent  duty  station  or  for  return  to  the  old permanent duty station.  Members on TEMDU are not attached to any permanent duty station. 4.   Temporary   additional   duty. Temporary additional duty (TEMADD) orders assign members to TEMDU in addition to their present duties and direct them  upon  completion  of  this  TEMADD  to  resume regular or temporary duty. POLICY The  policy  of  the  Department  of  the  Navy  is  to assign  all  women  members  to  billets  commensurate with   their   capabilities   to   the   maximum   extent practicable. The   policy   for   assigning   women members is as follows: 1.   Women may not be assigned to a unit, a ship, or  an  aircraft  that  has  a  combat  mission  except  as provided below.   If assigned on a vessel or an aircraft required   to   execute   a   combat   mission,   every reasonable effort will be made to disembark women before execution of such mission. 2.   Women   may   be   assigned   to   the   following types of duty: Permanent   duty   in   hospital   ships,   oilers, ammunition   ships,   refrigerated   stores   ships, transports,  training  ships,  and  vessels  of  a  similar classification  not  expected  to  be  assigned  a  combat mission. Temporary  duty  (TEMDU  or  TEMADD)  to any ship or aircraft not expected to conduct a combat mission  during  the  period  of  temporary  duty.    Such periods of temporary duty may not exceed 180 days. The Chief of Naval Operations and the Commandant of  the  Marine  Corps  may  issue  specific  guidelines governing these assignments. Permanent  duty  in  squadrons  where  such assignment  would  not  require  them  to  participate  as crew  members  in  a  combat  mission  or  to  embark, other  than  during  TEMADD,  in  vessels  that  may  be assigned combat missions.   They may be assigned to aircrew and support positions in squadrons that do not have  combat  missions.     Women  may  be  assigned nonaircrew   support   positions   on   land-based squadrons with combat missions.  The Chief of Naval Operations and the Commandant of the Marine Corps will specify those squadrons in which women may be assigned. 3.   Women  are  authorized  to  participate  as  crew members or passengers in aircraft engaged in training or  support,  including  landing  on  shipboard  flight decks under conditions permitting temporary duty on naval vessels, if the aircraft is not expected to execute a combat mission during the period of the assignment. 4.   Notwithstanding any of the provisions above, the Chief of Naval Operations and the Commandant of  the  Marine  Corps  may  preclude  women  from  the assignment to a noncombatant unit, ship, or aircraft. They may preclude such assignments when the type, degree,   and   duration   of   risk   of   direct   combat, exposure  to  hostile  fire,  or  capture  are  equal  to  or greater than the reasonably anticipated risks for land, air,   or   sea   combatant   units   with   which   they   are normally associated in a theater of operations. MISSION The   policy   outlined   above   delineates   when women members may serve on board Navy ships and 1-2