Optimized Descents and Cruise

CMC Electronics produced and shipped over 1000 Flight Management Systems (FMS), primarily to airlines around the world. For its latest FMS product CMA-9000, CMC is introducing fully coupled performance optimized vertical... [ view full abstract ]

CMC Electronics produced and shipped over 1000 Flight Management Systems (FMS), primarily to airlines around the world. For its latest FMS product CMA-9000, CMC is introducing fully coupled performance optimized vertical navigation. As a consequence, CMC product was selected on several critical aircraft programs. All of these aircraft (and many more in the future) will benefit from this project results expressed in terms of performance optimized continuous descent arrival's (CDA) or "Green Descents".

The main objective of this project is the design and the validation of a new FMS (Flight Management System) logic to integrate Continuous Descent Arrival (CDA)’s procedures and Cruise Speed and Altitude Optimization.

The goal is to optimize vertical profile in order to minimize Fuel Burn (and Flight Time) during Cruise and Descent procedure.

In other words, the goal is to reduce source emissions and improve aircraft operations by having the Flight Management System choose more efficient speeds, altitudes and flight paths for the aircraft flight.

This improved performance optimization in all phases of flight will allow routes to be flown at the optimum altitude and speed with efficient aircraft descent. All of these factors will reduce fuel burned and as such reduce emissions of CO2 and NOx on the retrofit and forward fit aircraft that the CMA 9000 FMS is installed in.

Collaboration between CMC and ETS teams has been performed in this project. In the laboratory of Active Controls, AeroServoElasticity and Avionics (LARCASE), research is performed in areas related to aircraft and helicopter modeling and simulation in collaboration with other Aerospace companies such as Bombardier Aerospace, Bell Helicopter Textron, CAE Inc., Thales Avionics and NASA DFRC. 15 internship students, 7 Master students and 4 PhD Student participated to the project along with CMC Scientists.

CMC in partnership with ETS conducted the research program to conceive and install and validate new algorithms and logics for Green Descents in their FMS.

As a result, a dozens of paper were published. The Cruise Altitude Optimization has been fully designed and developed through the course of the GARDN project. Early evaluation of the various solutions by ETS saved CMC Engineering group some time. It allowed CMC to fully develop the functionality in a short time frame. This research project also allowed ETS to train students on applied subjects. All students who participated in the project developed knowledge in aerospace concepts such as Navigation, A/C Performance and management.

CMC consider this project to be a success story as the development of the Cruise Altitude Optimization is a success. GARDN project came at the right time so that CMC could work with ETS. Led by CMC, ETS has evaluated several solutions meeting industry requirements. They especially did a heuristic evaluation of CMA-9000 Predictions Performance. It revealed that modeling of the A/C performance characteristic would not allow CMC FMS to compute a solution because of predictions approximations. This saved CMC Engineering team from doing such evaluation. ETS helped increasing TRL from 2 to 5. When CMC started focusing on the design and implementation of the function, most of the solutions were already exercised.

On the environmental side, VNAV is already installed in several aircraft using CMC VNAV descent and Cruise Speed Optimization to regularly save fuel and reduce emissions. Cruise Altitude Optimization is planned for entry into service by the end of the year.

This function proposes to the crew the most optimized altitude change in regards to the defined Cost Index (CI). It allows either reaching the Optimum Altitude or following it. Not following the optimum altitude will result in increased fuel burn rate. Following is typical Trip fuel loss when flying at a level different from the Optimum Altitude (e.g. FL370):