Airline flight departure procedures — choosing between noise abatement, minimum fuel consumption and minimum cost

Abstract

The advent of the commercial jet air liner, two decades ago, and growing public awareness of the noise of aircraft operations, led to the adoption by airlines of two distinct take-off departure procedures. A Standard Procedure for aircraft departures is usually recommended by the aircraft manufacturer, such that the air liner is operated in a safe and expeditious manner. A Noise Abatement Procedure was devised to reduce the noise impact of airline operations in the airport community environs. Generally, noise abatement procedures were thought to increase pilot work load and, therefore, reduce margins of safety, and increase fuel consumption.In the 1960s, when most of the air liners were powered by low by-pass ratio engines, the noise abatement procedure included a so called cut-back. This procedure included throttling back from take-off thrust (TOT) to less than climb thrust shortly after take-off (during cut-back) to benefit those communities living close to the airport. Subsequently climb thrust (MCLT) would be applied.