ISO/TC 20/SC 8 - Aerospace terminology

This document defines terms used in the field of rotorcrafts flight dynamics and aerodynamics, for example, rotorcraft design documents, with regard to rotorcrafts geometry and dynamic characteristics.

Cancels and replaces the first edition (1974) and addendum 1 (1986). Deals with the concepts, quantities and symbols used in the study of aircraft stability and control.

Deals with the concepts and quantities characterizing models of the air motions affecting the dynamic behaviour of the aircraft. The motion of the air with respect to the Earth is defined by the wind velocity in each point of the aircraft trajectory. In flight dynamic problems, it is usual to use mathematical models of the wind velocity field and its variation with time. The following models are defined: constant wind, wind gradients, discrete gusts, three-dimensional wind models, vortices. Other models can be defined by superposition of these models.

The aircraft is assumed to be rigid, of constant mass and of constant inertia. It is not equipped with systems modifying its natural dynamic behaviour. However, most of the definitions can be applied to the case of a flexible aircraft, of variable mass and of variable inertia. The general concepts defined are applicable to the atmospheric flight phase.

Deals with derivatives of forces, moments and of other quantities characterizing such forces and moments. The term "derivative" designates the partial derivative of a function with respect to an independent variable. These derivatives appear in the terms of the Taylor series representing the variations of functions with the independent variables. Is restricted to first-order terms. Terms of higher order would require additional definitions of higher order. The aircraft is assumed to be rigid. However, most of the definitions can be applied to the case of a flexible aircraft.

Gives basic definitions and deals with motion relative to the atmosphere, assumed to be at rest or in translational motion at constant velocity relative to the Earth. The aircraft is assumed to be rigid. However, most of the definitions can be applied to the case of a flexible aircraft. Describes axis systems, angles, velocities and angular velocities, aircraft inertia, forces, moments, coefficients and load factors, thrust, resultant moment of propulsive force, coefficients thereof, control forces and moments, motivators and their forces and moments.

Includes the quantities used in flight measurements. Defines fundamental characteristics of the atmosphere, geometric and geopotential altitudes, equivalent altitudes related to a standard atmosphere, physical quantities related to motion of the aircraft in the atmosphere, measurement of quantities related to motion of the aircraft in the atmosphere, speeds and indicated Mach number, on-board accelerometer indications and terms used for pressure differences in some countries.

Gives basic definitions and deals with motion of the aircraft and the atmosphere relative to the earth. The atmosphere is assumed to be at rest or in translational motion at constant velocity relative to the Earth. The aircraft is assumed to be rigid. However, most of the definitions can be applied to the case of a flexible aircraft. Describes axis system, velocities flight path angles and wind direction angles.

Is intended to give definitions specifying the terms: mission, controls, geometric configuration, situation of the systems, state of the aircraft, environment, flight points, effective flight points and flight envelopes, which are necessary for safety analyses, for qualification purposes.

Gives note 2 in 6.7.2.13. Includes the delection of the last part of the sentence, i.e. the example given in parentheses, so that the sentence reads as follows: 2. It may be useful to define the fin area by projecting the fin chord surface on some other surface that shall be specified.

Defines certain notions used for the geometric description of an aircraft for the purpose of flight dynamic studies. Does not give all the definitions that permit the detailed description of the shape of the aircraft. The aircraft is considered to be made up of various components. Defines general characteristics, overall dimensions of the aircraft, ground limit angles, fuselage, aerodynamic surfaces, wing and empennages. Gives figures.