ISO INTERNATIONAL STANDARD 1151-1 Fourth edition 1988-04-15 INTERNATIONALORGANIZATIONFORSTANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXKAYHAPOAHAAOPTAHM3ALMAOCTAHAAPTM3ALMM SN teiLu oc Seo Flight dynamics - Concepts, quantities and symbols Part 1: Aircraft motion relative to the air Mecaniqueduvol--Concepts,grandeursetsymboles Partie 1:Mouvement deI'avion par rapport a I'air Referencenumber ISO 1151-1 : 1988 (E) CopyrightIntermnational Organization for Standardization No reproduction or networking permited without license from IHS Not for Resale ISO 1151-1 : 1988 (E) Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the Iso Council. They are approved in accordance with IsO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 1151-1 was prepared by Technical Committee iSO/TC 20, Aircraftandspacevehicles. This fourth edition cancels and replaces the third edition (ISo 1151-1 : 1985) of which it constitutes a technical revision: this fourth edition includesDraft Addenda ISO/DIS 1151-1/DAD 1, circulated in 1986 (addition of a symbol to 1.5.4, 1.6.1.3 ISO/DIS 1151-1/DAD 2, circulated in 1986 (addition of annex B). Users should note that al International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. International Organizationfo:Standardization,1988 Printed in Switzerland CopyrgnnatinalrganizaiofoSandardization No reproduction or networking permitted without license from IHS Not for Resale ISO 1151-1 : 1988 (E) Iso 1151, Flight dynamics -- Concepts, quantities and symbols, comprises, at present, seven parts: Part 1 : Aircraft motion relative to the air. Part 2 : Motions of the aircraft and the atmosphere relative to the Earth. Part3:Derivatives of forces,moments andtheir coefficients Part 4 : Parameters used in the study of aircraft stability and control. Part5:Quantitiesused inmeasurements Part 6 : Aircraft geometry. Part7:Flightpointsandflightenvelopes ISO1151is intendedto introducethemainconcepts,toincludethemoreimportant terms used intheoretical andexperimental studies and,asfaraspossible,togive corre- sponding symbols. In all the parts comprising iso 1151, the term "aircraft" denotes a vehicle intended for atmosphere or spaceflight.Usually,ithas an essentiallyportandstarboard symmetry with respect toa plane.That plane is determined by the geometric characteristics of the aircraft. In that plane, two orthogonal directions are defined: fore-and-aft and dorsal-ventral.The transverse direction, on the perpendicularto that plane,follows. When there is a single plane of symmetry, it is the reference plane of the aircraft. When there is more than one plane of symmetry, or when there is none, it is necessary to choose a reference plane. In the former case, the reference plane is one of the planes of symmetry. in the latter case, the reference plane is arbitrary. In all cases, it is necessary to specify the choice made. Angles of rotation,angular velocities and moments about any axis are positive clockwise when viewed inthe positive direction ofthat axis. Ali the axis systems used are three-dimensional, orthogonaf and right-handed, which implies that a positive rotation through /2 around the x-axis brings the y-axis into the positionpreviou