Analysis of en-route vertical flight efficiency

Traditionally en-route flight efficiency is addressed in terms of horizontal flight efficiency. Only recently, more emphasis is being put on vertical flight efficiency as well, with a strong focus on the climb and descent phases of flight. Thus, en-route vertical flight efficiency remained untouched and since its impact can be significant, the Performance Review Unit of EUROCONTROL started this project. Efficient flight operations are at the heart of the political and operational debate. This includes a capability to assess and measure constraints imposed on airspace users impeding an efficient vertical flight profile. The work reported in this paper presents the development of a vertical flight efficiency metric based on the monitoring of European ATM performance. The method builds on assessing the vertical constraints between airport pairs on the basis of an analysis of the distribution of cruising altitudes of flights operating between similar airport pairs. The methodology is applied to monitor vertical flight efficiency in the en-route phase in Europe with a specific focus on the impact of level capping constraints. Results are available from 2015 and indicate that the highest amount of en-route vertical flight inefficiency happens within the geographical boundaries of the Maastricht and Karlsruhe Upper Area Control Centers.