Community Research and Development Information Service - CORDIS


TACTIC Report Summary

Project ID: 620121
Funded under: FP7-JTI
Country: Italy

Final Report Summary - TACTIC (in flight Trajectory optimizAtion through advanCed simulation TechnICs)

Executive Summary:
The Commercial and Airline Pilots are skilled to deal with their aircraft emergencies, because trained to handle such situations with standardized behaviour. On the contrary, when the occurrence of unusual situations, depending upon different and various mentioned factors, requires trajectory change during IFR navigation, pilot in command, involved in a short time analysis and synthesis, could be not able to consider all those aspects affecting the new flight trajectory negotiation.
In such situations the pilot may have great advantages in using additional capability providing supports and increased awareness in answering to trajectory change requests. A Decision Support System (DSS) can be introduced to allow the pilot to have in every instant the awareness of alternative paths, suggested by the tool, that can decrease trip time, fuel consumption and consequently chemical emissions and noise.
TACTIC project contributes to analyse and solve the problem of characterizing the pilot’s behaviour in decision making when unforeseen events force to a change in the reference trajectory with or without the help of an on-board Decision Support System. Its main objective has been to evaluate such a Decision Support System. The quantification of the advantages of such an interactive tool was the main output of the project. Eventual suggestions for enhancements of the tool as well as new interaction modalities or uses will also be provided.
To reach this objective, a simulation environment that replicates present and future ATC and airborne system configurations was set up.
This test bed environment was used to perform a set of simulations to study:
• the impact of different pilot behaviours in the decision making process when unforeseen events force a change of the reference trajectory;
• the impact of the Decision Support System on pilot workload and situation awareness and aircraft/airspace performances (e.g. fuel consumption, airspace capacity and efficiency, noise abatement) in all the phases of flight.

Project Context and Objectives:
The “System for Green Operations” (SGO) is one of the six Integrated Technology Demonstrators of the Clean Sky program. The main driver of SGO is represented by an eco-compatible design, aiming at reducing CO2 production and at optimizing aircraft energy management – see Fig. 2.
The SGO research consortium is organised in two branches: Management of Aircraft Energy and Management of Trajectory and Mission (MTM). One of the main fields of research considered by MTM to reach the objectives to reduce chemical (mainly CO2 and NOx) emissions and noise is to optimise in-flight trajectories, including the overall missions profiles, through mathematical optimisation and suggest to the pilot in very short time a new trajectory required by the insurgence of a compelling unforeseen event. Obviously the pilot cannot be excluded by the decisional loop and must continue to have the full authority on the trajectory to execute.
The true advantages for the pilot of such a Decisional Support System, in terms of saved time to the decision, in terms of psychophysical stress and in terms of reduced emissions, should be accurately evaluated and quantified. At first glance, remarkable savings may be assumed especially in complex flight phases requiring extensive communications between ground and pilot.
For a comprehensive numerical evaluation of the advantages in the overall decisional process, from the detection of an event requiring an immediate decision in terms of changes to the reference trajectory up to the actuation of the new trajectory, a step-by-step simulation of pilot’s behaviour and involved procedures should be performed for every flight phase.
Theoretical context
In order to study the behaviour of pilots in facing unforeseen events and to make easier the decision making process to tackle the new situation, in recent years many behavioural models have been developed.
All the most complete decisional schemes, like DECIDE (Detect-Estimate-Choose-Identify-Do-Evaluate) and 3P (Perceive-Process-Perform), follow an iterative path, starting from the detection that something has changed in the perceived scenario up to the undertaking of the needed actions to handle the new situation and the evaluation of their effects.
In such a context, a valid help can be provided by equipment able to evaluate in almost real time a new trajectory optimised in terms of emission and noise minimisation and suggested by means of a friendly MMI for a ready and easy interaction with the Decision Maker.
In addition, having in mind the present and future ATM environment, the procedures for having clearance by ATM to undertake the new proposed trajectory should be accurately evaluated too, for calculating the advantages (mainly in terms of time saving) of adopting such new equipment by comparison to the lack of it.
Main objectives
TACTIC project analysed and solved the problem of characterizing the pilot’s behaviour in decision making process when unforeseen events force to a change in the reference trajectory with or without the help of an on-board Decision Support System. The quantification of the advantages of such an interactive tool will be the main output of the project. Eventual suggestions for enhancements of the tool as well as new interaction modalities or uses will also be provided.

Project Results:
TACTIC main results may be resumed as follows.
From the analysis of the communication logs between pilots and ATC operator during the negotiation subsequent to the appearance of the risk zone it can be deduced that
using the DSS requires a trajectory negotiation based on published waypoints requires less phases:
• The pilot suggests an alternative trajectory and usually the ATCO approves it.
• After this first phase usually the ATCO requires a confirmation when the new trajectory begin to converge to the original flight plan.
On the other side, without the DSS:
• The pilot usually asks for a new heading and the ATCO agrees.
• While deviating from the flight plan the ATCO requests an estimated of the distance to be covered before resuming the navigation on the filed flight plan. Similarly with the DSS case, a confirmation is requested when the flight should converge to the original flight plan.
• In some cases the pilots asked for a new corrected heading causing an additional negotiation phase.
Using the DSS reduces also the radio frequency usage in terms of number of calls and total duration of the transmissions.
The simulations highlight no relevant differences in the average duration of the radio communication nor in the total duration of the negotiation. The ATCO always requests a confirmation when the aircraft is clear of the bad weather zone and about to converge to the original flight plan. So the total duration of the process is almost only related to the bad weather zone extension. This happens even when the pilot asks for a flight plan revision which should completely substitute the old one.
The DSS based negotiation identifies the trajectory earlier and more clearly. In the first radio communication session the trajectory is already defined; if the ATCO accepted the first trajectory proposal, the whole negotiation process would terminate in a single ATCO-pilot exchange.
Without the DSS, the trajectory negotiation is composed of three phases, all of them required to determine the geographical form of the deviating path. First the pilot requests a new heading is to stay clear of the bad weather zone. Usually after a while, the ATCO initiates a radio communication asking how long the pilots need to deviate. After covering this distance, the pilots or the ATCO initiate a communication to negotiate the point where the original flight plan will be resumed.
Without the DSS, the whole negotiation process has the following characteristics:
• The trajectory is not defined until the last phase of the negotiation, when the resume point is identified.
• Communication follows no predetermined timings. A variable amount of time can pass between the trajectory negotiation steps, according for example to the situation of the surrounding traffic.
• Communication can be initiated by ATCOs or pilots, without any defined rule.
On the contrary, the DSS suggests a more standardized negotiation which defines the trajectory immediately with more defined roles between pilots and controllers.
From the point of view of the fuel consumption and of the emission of pollutants (CO2, NOx), during the simulation a dedicated module of the CS system computed and collected data that can be resumed in the following table of fuel consumption and emission savings of NOx and CO2 when using the DSS with respect to the simulations without DSS aid. The table averages data for both airline and commercial pilots.
Fuel saving using DSS CO2 saving using DSS NOx saving using DSS
Case 1 5.62 % (70 Kg) 5.62 % (272 kg) 4.25% (588 g)
Case 2 5.31 % (89 Kg) 5.31 % (281 Kg) 2.11 % (324 g)
Case 3 1.03 % (1.03 Kg) 1.02 % (24 Kg) -0.9% (-152 g)
Average 4 % 4 % 1.82 %
Fuel savings and pollutant emission
The following considerations apply to the results of fuel consumption and pollutant emissions.
DSS suggests more direct trajectories generally leading to save fuel and consequently to reduce pollutant emissions.
Pilots flying without the aid of a DSS tend to join the scheduled flight plan earlier.
The DSS leads to the best results when it is used in a less constrained airspace system. One of the simulation scenarios (Case 3 in the table above) included a Point Merge System which requires more adherence to the flight plan in order to arrive to the merge point and follow the sequencing legs. In this context the fuel saving is considerably reduced because the air traffic Controller will request to resume earlier the previous flight plan.

Potential Impact:
Impacts of TACTIC project are expected both in the more general frames of “airplane operative procedures” and “environmental aspect” and with regard to important technical aspects.
The impacts on “environmental aspects” and “operative procedure” are related to the fact that DSS are considered inside the trajectory change negotiation workflow. This will bring consequences in the aircraft fuel consumption and chemical emission for the “environmental aspects while the new steps for the negotiation of the trajectory obviously impact on aeronautical “operative procedure”.
Verification of DSS usage also with future ATM scenarios will verify possible problems or modifications needed to integrate for example in a data link based communication system.
More in particular the following advantages are expected through TACTIC:
• higher confidence in the DSS interaction with pilots in different flight conditions;
• verification of pilot’s behaviour impact on the DSS usage and in trajectory negotiation procedure;
• evaluation of the range of situations of where DSS can be used taking an advantage for the pilot and where the DSS can increase in some way pilot workload creating possible risks for the safety of the flight.
The technical aspects involved in TACTIC will impact the European competitiveness especially at aircraft industry level allowing DSS to be considered as a help for the pilot situation awareness in several situations.

As far as dissemination concern, a number of actions were implemented.
A project public website was set up and kept updated during the project implementation.
The distribution and promotional material were prepared in forms of brochures and workshop flyers. Distribution of the brochures was done during various conferences and forums where the project members participated and presented the concept addressed within the TACTIC project.

The final workshop of the project was held in Rome – at the IDS premises on 22 July 2015. The objectives and the concept of the project were presented, followed by the interactive exercises involving all the participants in order to demonstrate the benefits of the usage of the DSS tool, as well as to identify remaining open issues and suggestions for possible improvements.

List of Websites:
In the frame of the TACTIC project a public website has been developed. It can be reached at the following address:
Ingegneria Dei Sistemi S.pA.
Via Enrica Calabresi, 24
56121 Pisa – Italy

Deep Blue S.r.l.
Piazza Buenos Aires, 20
00198 Rome – Italy

Related information

Reported by

Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top