THE FOLLOWING ASSUMPTIONS WERE CONSIDERED: (1) CERTAIN METHODS AND THEORIES OF CRIME DETERRENCE AND PREVENTION ARE FOUNDED ON TRADITION AND UNTESTED COMMON-SENSE VALUE JUDGMENTS; AND (2) IT IS IMPORTANT THAT RESEARCH BE DIRECTED TO THESE METHODS AND THEORIES FOR THE BENEFIT OF ADMINISTRATORS, TRAINERS, AND EDUCATORS. THE STATUS AND CREDIBILITY OF THEORY, AND THE EXISTENCE OF A DATA BASE FOR EVALUATION WERE DISCUSSED, AND A DESCRIPTION WAS PROVIDED OF THOSE METHODS AND THEORIES THAT RELY ON THE BELIEF THAT VISIBILITY AND MOBILITY HAVE A DIRECT EFFECT ON CRIMINAL ACTIVITY. THE STUDY FOCUSED ON THE FASTEST POLICE PATROL VEHICLE, THE HELICOPTER, SINCE IT IS BELIEVED THAT CRIME PREVENTION IS RELATED TO SPEED OF MOVEMENT. THE DATA, WHICH PROVIDED HISTORICAL AND PHILOSOPHICAL DETAILS OF PATROL MOBILITY, IN ADDITION TO AN INVENTORY AND DESCRIPTION OF POTENTIAL USE OF AIRBORNE VEHICLES, CAME FROM THE FOLLOWING SOURCES: (1) THE LITERATURE OF CRIMINAL JUSTICE; (2) A MITRE CORPORATION SURVEY (ALSO KNOWN AS THE CHESTER SURVEY); (3) AUTHOR SURVEY; AND (4) DEPARMENTAL EVALUATIONS. DATA WERE COLLECTED FROM THESE SOURCES PLUS 113 RESPONSES TO THE CHESTER SURVEY AND 75 RESPONSES BY MAIL TO THE AUTHOR'S QUESTIONNAIRE. EFFORTS TO TEST AND EVALUATE THE FREQUENCY OF USE AND THE PROBLEMS INVOLVED IN HELICOPTER POLICE PATROLS WERE REPORTED FROM REPRESENTATIVE CITIES IN THE STATES OF ARIZONA, CALIFORNIA, MARYLAND, MICHIGAN, OHIO, AND VIRGINIA, AND THE DISTRICT OF COLUMBIA. THE SUCCESS OF THESE TEXTS IN SCIENTIFICALLY EVALUATING PREVENTIVE PATROL IS CONSIDERED. IT WAS CONCLUDED THAT INCREASED VISIBILITY AND MOBILITY DO ACT AS A DETERRENT TO CRIME. IT IS EMPHASIZED THAT SCIENTIFIC EVALUATION OF POLICE PREVENTIVE THEORIES AND STRATEGIES IS A NECESSITY FOR RATIONAL (RATHER THAN EMOTIONAL) PLANNING. COOPERATION BETWEEN ACADEMIC RESEARCHERS AND POLICE IS RECOMMENDED. TABULAR DATA, FOOTNOTES, A BIBLIOGRAPHY AND APPENDIXES CONTAINING THE AUTHOR'S AND THE CHESTER SURVEY INSTRUMENTS ARE PROVIDED. (JCP)