AAR or Aar may refer to:

Aviation

• AAR Corporation, an American aviation engineering company

• Air-to-air refueling, the process of transferring aviation fuel from one military aircraft to another during flight

• Aarhus Airport in Mid Jutland Region, Denmark (IATA airport code AAR)

• Asiana Airlines of South Korea (ICAO airline code AAR)

Places

• Aar, a river in Switzerland, tributary of the Rhine

• Aar (Lahn), a tributary of Lahn river in Germany, descending from the Taunus mountains

• Aar (Dill), a tributary of Dill river in Germany, also in the basin of the Lahn

• Aar (Ill), a branch of the Ill river that separates from it in Strasbourg, France and rejoins it further north

• Aar (Twiste), a tributary of Twiste river in Germany, in the basin of the Weser

• Aar (village), a village in Rajasthan, India

• South American–Antarctic Ridge, also known as the American–Antarctic Ridge, a mid-ocean ridge in the South Atlantic

• Antarctica, IAAF code AAR

Military

• After-action review, a structured review process used by the U.S. military

• After action report, a retrospective analysis

• Assistant Automatic Rifleman, a soldier who carries ammunition; see Rifleman#Modern_tactics

Organizations

• All American Racers, a former Formula 1 and CART team

• Allens (law firm), a law firm (formerly known as Allens Arthur Robinson)

• American Academy in Rome, research and arts institution in Rome

• American Academy of Religion, an association of academics who research or teach topics related to religion

• Association for Automated Reasoning, a non-profit that seeks to advance the field of automated reasoning

• Association of American Railroads, an industry trade group representing the railroads of North America

Transportation

• AAR coupling, railway coupling specification of the Association of American Railroads

• AAR wheel arrangement, Association of American Railroads system for describing wheel arrangement of locomotives

• All-American Road, a designation for some national scenic byways in the US

• Ann Arbor Railroad (disambiguation)

Other uses

• Aar (Star Wars), fictional planet in Star Wars universe

• Aar, a fictional planet of the star Deneb, in the "Captain Future" stories

• The All-American Rejects, an American rock band

• Air America Radio, a domestic US radio network

• Average accounting return, a capital budgeting investment rule

• Adam's apple reduction, a surgery

• Afar language (ISO 639 language identification code)

• African American Review, a journal

• Amino acid response, the biochemical response of a mammalian cell starved of amino acids

• "At any rate"; see List of SMS abbreviations

• Alkali–aggregate reaction, a chemical reaction leading to expansion in concrete

See also

• Ahr, a river in Germany, tributary of the Rhine

• Aare (disambiguation)