Book excerpt: The new European Joint Aviation Requirements (JARs) lay down rules governing the minimum levels of performance which must be attained by every type of public transport aeroplane. These rules cover matters such as weight, altitude and temperature, take-off and landing distance, cruise flight level and speed, and descent angle and rate. The subject of aircraft performance forms an important part of all JAR Flight Crew Licensing examinations for commercial and airline transport pilot licences, and this book provides a clear but authoritative text on a difficult topic. It will also be of interest to commercial pilots needing to upgrade their annual ground test to JAR standards, and to flight planners, operations controllers and airport operators.