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Airline TriAls of Environmental Green flIght maNAgement functions

Final Report Summary - ATAEGINA (Airline TriAls of Environmental Green flIght maNAgement functions)

Executive Summary:
ATAEGINA (Airline Trials of Environmental Green Flight Management Functions) is a Research & Development project funded by the Clean Sky Joint Technology Initiative and project-managed by Pildo Labs. It is designed to evaluate and test three new operational concepts (ECO STEP, A-IGS and MCDP) on real daily operations, implying random perturbation factors and real flight conditions.

• The MCDPs (Multi Criteria Departure Procedure) are based on Noise Abatement Departure Procedures (NADPs) with the difference that, apart from providing noise reduction on the airport surrounding areas, the intent is to reduce the fuel burn which minimizes the COC (Cash Operation Costs) and the emissions of CO2 and NOx during departure.

• The ECO STEP concept is an optimized multi-step procedure, used mainly for extended range cruise, the objective of which is the computation of an optimized cruise profile (in pre-flight and during flight) which aims at minimizing fuel consumption and/or flight time.

• The A-IGS is a class of steeper approach operation which is computed dynamically on board by the FMS.

Aside from the A-IGS concept, which related ATAEGINA activities were stopped in accordance with coordinator, ECO STEP and MCDP concepts were evaluated by analysing its compatibility with airline aircraft operations and performing a safety assessment.

Initially, MCDP flight simulations were successfully performed demonstrating the compatibility of the new functions introduced for the MCDP operation in non-automatic execution with the current flight management functions. Furthermore, it was intended to execute ECO STEP simulation tests. However, due to large delay in obtaining nominal data from transoceanic flights and the unavailability to provide with the ECO STEP profiles, the simulation tests were not carried out.

Then, a real MCDP flight trial campaign was planned and executed from January 2016 until April 2016. Using the data recorded during the MCDP flight trial campaign, different assessments were performed. Whilst considering the conclusion from the full assessment, the over-riding conclusion to be drawn from the MCDP flight campaign is that MCDP operation is a new operational concept that is feasible to be carried out in daily operations, and it could be fully accepted by flight crew with some minor procedure modifications. However, due to the short number of MCDP flights performed, there are no conclusive results regarding the benefits that MCDP could provide in noise, fuel and emissions reduction.

Finally, an analysis related to MCDP integration/certification aspects was carried out presenting the different integration approaches, identifying on-board equipment modifications and regulations to be certified.

Project Context and Objectives:
The SGO (Systems for Green Operations) part of Clean Sky aims at developing systems which enable environmentally sustainable flight operations. New operational concepts are being evaluated for integration in future flight management systems generations, in order to minimize environmental effects and provide more sustainable and green operations to airliners.

Among those, the Multi Criteria Departure Procedure (MCDP), ECO STEP and Adaptive Increased glideslope (A-IGS) have been modelled and tested in a laboratory environment showing significant savings in terms of fuel consumption and environmental pollutants.

Multi Criteria Departure Procedure
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The MCDPs are based on Noise Abatement Departure Procedures (NADPs) with the difference that, apart from providing noise reduction on the airport surrounding areas, the intent is to reduce the fuel burn which minimizes the COC (Cash Operation Costs) and the emissions of CO2 and NOx during departure.

The compromise between fuel consumption, emissions and noise is accomplished by optimizing the following operational parameters:
• THR RED ALT: Thrust Reduction Altitude
• ACCEL ALT: Acceleration Altitude
• ECO SPD: Eco Speed
• ECO END ALT: End of Procedure Altitude

Aforementioned parameters should be optimized by taking into account some fixed and variable conditions of the scenario where the MCDP would be executed:
• Fixed conditions: airport, departure runway, SID selection, terrain, surrounding noise-sensitive areas ...
• Variable conditions: aircraft configuration, weather, obstacles, ATC requirements ...

Then, the MCDP concept consists in an improved NADP intended to comply with actually published procedures while providing flexibility to the airline to optimise fuel consumption, emissions, and/or noise for given mission conditions.

ECO STEP
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The ECO STEP concept is an optimized multi-step procedure, used mainly for extended range cruise, the objective of which is the computation of an optimized cruise profile (in pre-flight and during flight) which aims at minimizing fuel consumption and/or flight time. The optimized trajectory is controlled through altitude changes (flight level) using the on board knowledge of the weather forecast and aircraft configuration along the envisioned trajectory.

The ECO STEP is based on three main pillars:
• ECO Cruise as strategic “multi step profile” computation in pre-flight: During the flight planning, a first computation of the whole optimized cruise profile will be developed with the weather forecast and the predicted mission data. These first parameters computed for the ECO STEP will be the ones submitted in the flight plan.
• ECO Cruise as tactical “multi steps profile” computation during flight: The ECO STEP function will allow to update and modify the optimized profile computed during the flight planning phase and to adapt the optimum steps with the weather update and the refreshed aircraft state data while performing the cruise phase.
• ECO Cruise as tactical “step adjustment”: A tactical adjustment in the next step can be performed taking into account the last weather update and/or the aircraft state. This Eco Cruise principle will deliver the updated and final step in order to optimize the whole procedure and achieve the maximum benefits in fuel consumption and/or flight time.

With the implementation of these three principles, it is expected to achieve a reduction in fuel consumption and in flight time.

Adaptive Increased Glide Slope
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The A-IGS is a class of steeper approach operation which is computed dynamically on board by the FMS. The steeper approaches, defined in PANS-OPS ICAO Doc. 8168 as non-standard procedures, are those approach procedures involving glide paths greater than the maximum descent gradient/angle (i.e. 3.5° for Cat I precision approaches).

Through A-IGS, the approach glide path is adapted by the FMS to obtain the desired fixed rate of descent taking into account the conditions during the flight, such as:
• Aircraft data (mass, configuration, etc.)
• Environmental conditions (wind, temperature, altitude, etc.)

As any steeper approach, A-IGS intends to reach two targets:
• noise reduction on the airport surrounding areas, and
• aircraft fuel savings.

Then, the A-IGS concept allows executing steeper approaches, whenever it is possible, avoiding any operational inconvenience while providing flexibility to the airline to optimise emissions and/or noise for each mission.

ATAEGINA Objectives
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ATAEGINA project is aimed to test previous concepts (ECO STEP, A-IGS and MCDP) provided by SGO on real daily operations, implying random perturbation factors and real flight conditions.

As a first step, and after analysing the FM functions provided by Clean Sky and their compatibility with actual fleet operations and avionics equipage, the ATAEGINA consortium will set up a series of scenarios to be run in full flight simulators. The simulations will serve to evaluate the different safety risks that can appear due to these new FM functions, and to mature the operational procedures and get the feedback from pilots.

With the outputs from the simulations, and taking into account the identified operational constraints for the trials (e.g. airport time/daily loads), the final flights candidate list per flight optimization type (ECO STEP, I-AGS and MCDP) will be defined. Data will be collected during the green flights for later post-process and comparison with historical data, as well as with data collected at the beginning of the project, during the so-called nominal flight campaign.

Using all data collected during the flights, different assessments will be performed in 3 specific fields:
• Operational test assessment for verifying: the correctness of the operations, the acceptability of the green functions by pilots/controllers, and the potential blocking points for a wider deployments.
• Noise analysis and comparison between green flights and nominal flights.
• Fuel consumption / generated emissions analysis and comparison between green flights and nominal flights.

Finally, an initial assessment about the difficulties and barrier that green concepts can face in its deployment, and the potential users that may be interested in adopting it, will be drafted.

Project Results:
GREEN FUNCTIONS ANALYSIS
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Aside from the A-IGS concept, which related ATAEGINA activities were stopped in accordance with Thales, the assessment of ECO STEP and MCDP was carried out through the following actions:
• Preparation of the Test Plan: Test plan was completed by defining the appropriate flight experiment plan to validate the operational acceptability of each concept execution method as detailed in the Concept of Operations document. The outcomes of the different tests defined aimed to support the concept to reach next project phase, where the operational aspects and benefits of will be analysed throughout real flight trial campaign.
• Development of CONOPs: A Concept of Operations report was produced offering a detailed description of the green concepts; and, explaining how each concept is carried out during the different parts of its planning and execution. The CONOPS report identifies which actions should be taken, in what sequence and includes the required operational information such as: system elements, conditions of usage, required services, training, etc.
• Development of Safety Assessment: The Safety Assessment was developed to assess any potential safety threads needed to be taken into account to perform a successful flight test campaign in the framework of ATAEGINA’s project. To achieve this, potential safety deficiencies derived from the new concept operation needs were clearly defined to enable any impact on ATC services provided and ANS/ATM operational systems to be identified and mitigated, if necessary.

SIMULATIONS EXECUTION AND ASSESSMENT
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In order to perform a first validation of the concepts’ definition, a simulator experiment was planned. Additionally, the simulator experiment was intended to validate all safety assumptions taken in the safety assessment and to generate a first selection of candidate flights for a real flight campaign.

Initially, it was intended to plan and execute ECO STEP simulation tests. However, due to large delay in obtaining nominal data from transoceanic flights and the unavailability to provide with the ECO STEP profiles, the simulation tests were not carried out.

For MCDP concept, the following actions were taken:
• Preparation of questionnaires: In order to keep record of simulator participants’ expert opinions and judgments, regarding potential operational issues arising from the simulations, a run questionnaire was designed. This was filled individually by each Subject Pilot after each simulation run. The aim of this questionnaire was to gather information about pilot’s experience after flying an MCDP scenario. This is achieved mostly by doing concrete questions over the safety and acceptability of the MCDP operations performed during the run.
• Execution of MCDP simulator experiments: MCDP flight simulations were performed at the 17th of December 2014. The experiment was devoted to demonstrate the compatibility of the new functions introduced for the MCDP operation in non-automatic execution (as described in MCDP CONOPS) with the current flight management functions in order to assess whether MCDP is acceptable and compatible with fleet daily operations.

This was achieved by evaluating the pilot acceptance of the MCDP concept in various scenarios executed in two sessions: one during the morning, and the second during the afternoon.
• Analysis of experiments: The data gathered during the simulations (simulator logged data, pilot’s answers to simulation questionnaires, comments from the pilots and consortium conclusions during the subsequent analysis meeting) were used to assess different subjects:
o The achievement of the experiment objectives defined in the Simulator Test Plan. It was analysed by checking if each objective acceptance criterion has been met or not, and which were the causes.
o The pilots’ remarks were evaluated to make an overview of the advantages and disadvantages of the MCDP concept and the simulation experiment.
o The research questions and their hypothesis formulated in the Simulator Test Plan, were assessed by analysing if their associated validation objectives were met.

Among all the results assessed from the responses to the questionnaires and comments from simulations’ participants, the over-riding conclusion to be drawn from the experiments themselves was that MCDP operations execution are considered safe, acceptable and compatible with airline daily Flight Management Functions. However, some minor concerns were identified during the experiment:
• The MCDP parameters table was not covering all types of scenario conditions, forcing pilots to interpolate to find the right MCDP values on board. It was agreed that no interpolation operation should be performed by the pilots, as long as this could add undesirable extra workload and may lead to errors in the MCDP parameters procurement.
• While analysing the MCDP real advantages, it should be taken into account that using Take-off Thrust for a longer time could increase the aircraft maintenance costs, even if it supposes lower fuel consumption.
• Whilst identifying the implications for a single flight simulator activities to not address operability of implications in a real-world multi flight environment. ATC fast time or real time simulations (ideally real flight trials but this mot be possible in the scope of ATAEGINA) - will be required to analyse the practicality, safety, operational requirement and cost-benefits in the real world. This will be especially important to understand the implications of using the new procedures in a mixed traffic environment where some aircraft fly conventionally and others use the new procedures.

FLIGHT TRIALS EXECUTION AND ASSESSMENT
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In order to keep the validation of MCDP concept within a nominal operational environment, after the assessment of the simulation exercises, a real flight trial campaign was conducted. The MCDP flight trial campaign, performed in Lisbon airport, was extended from January 2016 until April 2016. During this period, the following actions were performed:
• Nominal flight data collection: Even if there was historical FDR available, collected during the past years, it was decided to record data from nominal flights during the green trial campaign period. Hence, FDR data of nominal flights was recorded from January 2016 until April 2016.
• Green trials execution: MCDP flight trials were performed from January 2016 until April 2016, as specified in the Operational Test Plan. All the flights’ data were properly recorded to be analysed on post-process basis. After each flight, flight crew was asked to fulfil a questionnaire to obtain subjective feedback from them.
• Data consolidation: After receiving the files, data obtained from the aircraft and sensors was consolidated. Different checks were carried out to detected missing or incoherent data.

During the flight campaign 145 MCDP flights and 132 nominal flights were recorded. Per each flight, the following information and data files were obtained when available: aircraft FDR files, meteorological data, noise monitoring data, flight crew questionnaires (for MCDP flights) and MCDP strategy/parameters used.

Then, based on all the previous data, the following analysis were performed:
• Operational test assessment: Based on the data gathered during MCDP flight trials, it was verified the correctness of the operations, the acceptability of the green function by pilots and the potential blocking points for wider deployments.

From the operational assessment, the over-riding conclusion from the MCDP flight campaign is that MCDP operation is a new operational concept that is feasible to be carried out in daily operations, and it could be fully accepted by flight crew with some minor procedure modifications.

Some of the issues that were raised during the MCDP flight campaign are result of the way the MCDP concept has been adopted for the trials execution. Having the MCDP operations fully integrated inside the FMS (instead of using tables) would be translated into a more automatized procedure that should not increase the flight crew workload, causing a wide acceptation and better results.

• Noise and emissions analysis: Based on the data collected through the noise monitoring system, noise modelling studies were conducted using calibrated noise model. Additionally, fuel and CO2 assessment was performed based on FDR and QAR data available from aircraft recordings during the trials. Whilst the fuel consumed was available directly from aircraft recorded data, the emissions were estimated via a downstream calibrated model.

Based on the MCDP noise assessment, the statistical analysis of the noise modelling results for MCDP and nominal flights does not yield conclusive results. The differences detected for the noise contours remain slight (< 1dB). The changes to modelled noise footprint area arising from the use of MCDP were in the order of 0% to 1.4%. Event this benefit was not proven statistically speaking. Thus, in additional to the perceived noise benefits in noise level from individual MCDP flight being considered as being useful but of low significance; the cumulative benefit in terms of the change to noise contours and the population reducing within these can also be considered to be small and potentially insignificant.

Based on the MCDP fuel and emissions assessment, the statistical analysis of the fuel and emissions modelling results for MCDP and nominal flights does not yield conclusive results. There were significant variations in fuel consumption between supposedly similar flights of both MCDP and nominal flights. This variability is caused by a number of factors that significantly affect fuel consumption and emissions and that are beyond human control and cannot be accurately accounted for. Notably, the results on the fuel and emissions modelling are impacted by factors such the weather conditions along the aircraft trajectory, variation in aircraft weight and variations in vertical profile created by differences in pilot or autopilot actions. This variability, coupled with the relatively smaller differential in fuel consumption between MCDP and nominal flights, means that it is impossible to be certain on the scale of the fuel and emissions benefit from MCDP deployed during the trial.

• Integration in Europe: It was assessed the acceptance that MCDP concept could obtain from European stakeholders, and the potential difficulties that the MCDP concept could face in its deployment. In this framework, a report was drafted offering an initial assessment by defining: the integration on-board that could be considered, the required information to compute the optimization parameters, the different equipment that would be needed on-board in order to manage MCDP operations, and the regulation and standards that MCDP system should be forced to fulfil.

Potential Impact:
The dissemination plan for ATAEGINA project was focused on spreading the objectives and activities that took place during the development of the project, as well as on informing and giving awareness after its completion about the conclusions and contributions to the Clean Sky framework achieved.

A project website (http://ataegina.pildo.com) was created to be the main dissemination channel of the project. This contains the project basic information, as well as the objectives and latest actions.

Additionally, some abstracts were submitted to green aviation symposiums focusing its contents on the practical application of data science tools in the framework of ATAEGINA.

List of Websites:
ATAEGINA Consortium Main Contacts:
• Brent Day (Pildo Labs) – land: +44 (0) 1963 364580 – email: brent.day@pildo.com
• Josep Montolio (Pildo Labs) – land: +34 931828844 – email: josep.montolio@pildo.com
• Joaquim Geraldes (NAV Portugal) – land: +351218553530 – email: joaquim.geraldes@nav.pt
• Duarte Gouveia (ANA) – land: +351 963039288 – email: dpgouveia@ana.pt
• Isabel Maria Oliveira (ANA) – land: +351 21841888 – email: isabel.rebelo@ana.pt
• António Aguiar (TAP Portugal) – land: +351 218415942 – email: aaguiar@tap.pt
• Emilia Suomalainen – land: +33 171194586 – email: emilia.suomalainen@env-isa.com
• Anne-Laure Verneil – land: +33 171194586 – email: anne-laure.verneil@env-isa.com