This revised edition designed for GCSE and TVEI courses, is part of a series intended to develop students' interest and understanding of science. Although written with the less able student in mind, the modules can be used with students capable of a wide range of GCSE grades by using the extension material in the teacher's guides. The units in each book are self-contained and can be taken in any order to provide a flexible and broad science course. The series is intended to assist students with their practical skills and approach to problem solving, whilst developing their ability to work both independently and as a member of a team. Each unit consists of a students' book and a teacher's guide. The students' book provides practical investigations and questions and real-world examples of the scientific principles investigated. The reading level has been kept as low as possible and has been checked by a language consultant. The teacher's guide contains background details plus course and unit objectives. There are answers to selected questions in the students' book and advice on apparatus and safety precautions as well as extension work for more able pupils in the form of black-line masters for duplication as required. This text explains how flight is possible and encourages students to build and to use models. It considers the various modes of flying such as parachutes, gliders, aircraft and space craft.