 The International Civil Aviation Organization ( ICAO ) defines general aviation ( GA ) as " an aircraft operation other than a commercial air transport operation or an aerial work operation . " It defines commercial air transport ( CAT ) as " an aircraft operation involving the transport of passengers , cargo or mail for remuneration or hire " , and aerial work as " an aircraft operation in which an aircraft is used for specialized services such as agriculture , construction , photography , surveying , observation and patrol , search and rescue , aerial advertisement , etc . " 
