title: Pressure by definition.
authors.affiliation: PHI Air Medical in Santa Fe, NM, USA. macevac@yahoo.com
authors.forename: Ed
authors.initials: E
authors.lastname: Macdonald
mesh_terms: D000060:Accidents, Aviation / Q000517:prevention & control; D017732:Air Ambulances / Q000600:supply & distribution*; D004465:Economic Competition; D006801:Humans; D017751:Safety Management; D013315:Stress, Psychological