‘Continuous descent operations’ allow an aircraft to approach and land on the runway in one smooth motion, rather than the traditional ‘stepped’ approach to an airport, where engine power was needed to level off at multiple altitudes before landing.

ACS 70 graphicThis saves fuel and can also reduce noise burdens on communities. Given the different types of airport environment – some have very congested and complex airspace – the technique is not always possible and is individually designed to suit each airport.

Continuous descents are now in operation at many airports worldwide; here are three examples of the concept in action:

At Budapest Airport in Hungary, aeronautical engineering company PildoLabs worked with HungaroControl and Wizz Air to implement the technique, which has been made available to all airlines operating there since March 2013. The trials demonstrated that fuel use and CO2 could be cut by 48% for each arrival, reducing CO2 by 323 kilograms for each aircraft that uses it. The project, known as REACT-Plus, is co-financed by the SESAR initiative.

Kenya Airways has worked with the Civil Aviation Authority and IATA to implement the technique at Nairobi’s Jomo Kenyatta International Airport. In the six years the airline has been using continuous descents, it has been able to undertake the procedure on 85% of arrivals at 15 airports and has avoided five million tonnes of CO2. By 2020, Kenya Airways aims to have 100% of arrivals use the process and roll it out to airports across Africa.

Improved continuous descent techniques across 15 airports in the United Kingdom have cut CO2 emissions by 20,000 tonnes in nine years, with a project to increase use of the techniques by 5% in the coming years, saving a further 10,000 tonnes of CO2 with 30,000 quieter flights.