Performance comparison between TEMO and a typical FMS in presence of CTA and wind uncertainties

Abstract

Continuous Descent Operations (CDO) with Con- trolled Times of Arrival (CTA) at one or several metering fixes could enable environmentally friendly procedures without com- promising airspace capacity. Extending the current capabilities of state-of-the-art Flight Management Systems (FMS), the Time and Energy Managed Operations (TEMO) concept is able to generate optimal descent trajectories with an improved planning and guidance strategy to meet CTA. The primary aim of this paper is to compare the performances of TEMO (in terms of fuel consumption and time error) with respect to a typical FMS, that is an FMS without re-planning mechanism during descent based on time or altitude errors. The comparison is performed through simulation, using an A320-alike simulation model and considering several scenarios in presence of CTA and wind uncertainties. Results show that TEMO is capable of guiding the aircraft along a minimum fuel trajectory still complying with a CTA, even if significant wind prediction errors are present. For a same scenario, a typical FMS without re-planning capabilities or tactical time-error nulling mechanism during the descent, would miss the CTA in most cases.