Ecological and Cost Advantage from the Implementation of Flight Simulation Training Devices for Pilot Training

Abstract

The paper discusses a case study of obtaining an airline pilot license in integrated training—the so-called “from zero to Airline Transport Pilot License”. The environmental implications of simulator-based training were examined across multiple dimensions. Key areas of research include the reduction of harmful exhaust gases pollution associated with traditional flight training activities. Based on our analysis, it can be stated that increasing the use of Flight Simulation Training Devices in pilot training should be significant consideration. This approach brings many benefits, especially ecological ones. Changing the training program and increasing the use of flight simulators can result in a reduction of CO₂ emissions by up to 70%. Based on country specific electricity factors, CO₂ emissions during flight training in each EU country were calculated. Using Levelized Cost of Electricity average value to calculate training costs in EU countries depends on the mix of energy sources (wind, photovoltaics, carbon and gas). The findings highlight the significant ecological advantages of simulator-based training methods in mitigating the environmental footprint of aviation operations. By seeking to minimize environmental disruption and increase training efficiency, the adoption of simulators is a sustainable approach to pilot training that is consistent with global efforts to mitigate climate change and protect natural ecosystems.

1. Introduction

1.1. Introduction to the Topic of Article

With the dynamic development of aviation, the global demand for highly qualified pilots is constantly growing. However, increasing the number of flight schools and intensifying pilot training inherently leads to greater consumption of natural resources and an increase in greenhouse gas emissions associated with training flights. Targeting net zero emissions by 2050, international aviation agencies are pushing to reduce emissions directly at their source [1,2,3]. In the face of growing challenges related to climate change and environmental protection, the use of flight simulators can be treated as a prospective solution, capable not only of increasing the effectiveness of aviation training, but also of significantly reducing the environmental impact associated with this process. The inclusion of flight simulators in aviation training programs proved to be a revolutionary approach from the very beginning [4,5]. The advantages of using them were immediately identified: greater training opportunities and lower cost than an hour of flight. Over time, significant ecological benefits have also been seen. When analyzing the literature sources related to the subject discussed in the article, several articles can be found concerning the reduction of emissions from air transport and introducing alternative power sources, including the use of electric aircraft [6,7,8,9] Literature dealing with Flight Simulation Training Devices (FSTD) and their impact on the environment and training is still very scarce and has only emerged in the recent years. In literature, studies can be found that describe training programs and the use of different types of simulators [10,11,12,13]. However, there is a lack of articles directly related to the subject discussed in this article. The authors believe that emphasizing the impact of using FSTD on energy consumption and emissions during pilot training and presenting quantitative analyses will indicate how important it is to use this type of device and suggest expanding their use. This may have an impact on the recommendations formulated in legal sources and regulations. This article attempts to analyze the ecological benefits of implementing flight simulation training devices in the aviation training process. By synthesizing available scientific research, empirical data, and presenting an analysis of energy consumption and emission in different flight simulator use scenarios, this article aims to examine the environmental impacts of simulator training compared to traditional airborne training methods. The primary goal of this analysis is to show how flight simulators can contribute to reducing greenhouse gas emissions and fuel consumption generated by training flights. The additional aim of the research is to compare different scenarios of FSTD use to check which one will be the most advantageous in terms of energy consumption, emissions, and training. By exploring these issues, this article aims to highlight the importance of simulation piloting as a strategic tool to support aviation sustainability goals. In the context of global efforts to reduce climate change and protect the environment, understanding the ecological benefits of implementing flight simulators is extremely important for the future of flight training and the long-term sustainability of the aviation industry [14,15,16,17]. By synthesizing existing knowledge and presenting practical implications, this article contributes to the discussion on the role of flight simulator training as a key element of aviation environmental footprint reduction strategies.

1.2. ATPL Integrated Training Characteristic

Integrated flight training is a comprehensive training program that aims to prepare future pilots to serve as captains in airlines. Such training ends with the student pilot obtaining an ATPL (Airline Transport Pilot License). The structure of the training program includes both theoretical and practical parts. The first stage of integrated aviation training is theoretical courses, which cover several subjects such as aviation law, meteorology, navigation, flight principles, and on-board equipment. Training takes place in flight simulators, which enable simulation of various aviation conditions and emergency scenarios in a controlled environment. Pilots improve their flying skills by responding to a variety of situations without having to expose themselves to the risks associated with training flights. The next stage of integrated aviation training is practical training flights, during which student pilots gain experience in real aviation conditions. With the support of experienced instructors, pilots develop their skills in navigation, piloting, and flight management. Each training program ends with the evaluation of the pilot’s skills and the awarding of an appropriate certificate authorizing him or her to practice as a pilot. Participants who successfully complete the program receive an airline pilot license (ATPL) and are ready to work for an airline.

The path to obtaining an ATPL license is opened by obtaining the first level of aviation qualifications that authorize the student to fly airplanes—a private pilot license (PPL). In short, obtaining this license involves learning 100 h of theory and performing 45 h of flights. Next, future airline pilots need to obtain the VFR NIGHT (Visual Flight Rules) qualification, which involves performing 5 h of night flights. The student then builds their flight experience. The minimum is 50 h of flight as a commander in navigation flights. Achieving this entitles the pilot to start IR/SE (Instrumental Rules/Single Engine) training, i.e., training for instrument rating flights on single engine aircraft. IR qualifications are obtained successively, and the training lasts 50 h. Then, the pilot starts to obtain the MEPL (multi-engine piston land aircraft) qualification, which takes 6 h. After another 15 h, the student can obtain a CPL (Commercial Pilot License). The next step is to obtain the right to fly according to instrument indications on IRME (Instrument Rating Multi Engine) aircraft, which takes a minimum of 7 h. Obtaining a CPL license requires a minimum of 100 h of flight time as a pilot-in-command and a minimum of 150 h of general flight time. After completing the theory for the ATPL license (650 h), the pilot can obtain the so-called ATPL Frozen license. Subsequent training and flights bring the pilot closer to obtaining airline pilot qualifications. These are multi-crew MCC (Multi Crew Cooperation) ratings, consisting of 25 h of theory and 20 h of practice, and JOC (Jet Orientation Course) ratings for jet aircraft flights, consisting of 10 h of theory and 6 h of practice. In some centers, pilots also undergo UPRT (Upset Prevention and Recovery Training) training in preventing and recovering the aircraft from critical situations, consisting of 5 h of theory and 3 h of practice. An example of the integrated aviation training for the ATPL license is shown in Figure 1.

All the above-mentioned qualifications and training are obtained after meeting the assumptions of the training program of a given aviation training organization. The training program is divided into stages, and the stages into individual tasks. Aviation regulations indicate the minimum hours that must be completed for a given task. Stages 1, 2, and 3 are carried out on a single-engine piston aircraft and last 10, 20, and 50 h respectively. In the example analyzed center, they include a total of 98 h of flight. Stage 4, according to the regulations, must include at least 33 h of flight training and 8 h on a flight simulator. In the example center discussed, it was assumed that the total duration of flight would be 44 h and 40 h in the simulator. The fifth stage, both in the regulations and in the presented center, includes 3 h of flight on an airplane (UPRT training). Stage 6 is MCC training, which is entirely conducted on a flight simulator. It lasts 35 h.

To sum up, the training selected for further analysis in its entirety covers 220 flight hours, of which 125 are carried out on an airplane and 95 on a flight simulator.

2. Materials and Methods

2.1. Research Methods for Measuring Energy Consumption

Research on energy consumption during flight was carried out using the CKAS MotionSim5 flight simulator (Westmeadows, Australia). This was developed in the Simulator Research Laboratory at Poznan University of Technology. This device can be certified as an EASA FNPT II MCC Flight Trainer (Flight Navigation and Procedure Trainer Multi Crew Coordination). This simulator is made to simulate four types of aircraft. In the presented research, both a piston engine (PE) and a light jet aircraft (VLJ) are chosen. A more accurate description of the device was shown in articles published by our research group, for example in [19,20]. To obtain energy consumption results, five pilots were asked to perform flights. Each of the pilots was informed about the purpose of the research and could resign from it at any time. All tests were carried out between 10 a.m. and 3 p.m., and the pilots reported that they were refreshed and fully fit for flight. The experience of the pilots was between 100 and 240 h of flight time. Participants were divided into two groups according to their flight experience. All pilots were men aged 19 to 23. Each of them made flights that differed in the selected weather scenario, the propulsion used, and the use of the motion platform. The results of these tests allowed for the determination of energy consumption in individual flight phases in each of the mentioned simulator configurations. To perform calculations of energy consumption during integrated aviation training, flights with three different configurations was needed: flights with one-piston engine propulsion (PE), two-piston engine propulsion (2PE), and jet engine propulsion (VLJ). Each flight were performed in CAVOK weather conditions with the motion platform enabled. Due to energy consumption calculations, the hours of integrated ATPL training were divided among those performed in PE aircraft, 2PE aircraft, and VLJ aircraft.

The energy consumption of the flight simulation system was based on the measurement of all electricity connections supplied to the elements of the CKAS MS5 system. The single-phase connection of the Motion system (80 A) was characterized by the highest maximum load. The second source of energy was a three-phase connection (16 A) for connecting a control and visualization unit based on a cluster consisting of five computing units. The whole of the above installation is connected in parallel with the UPS system, which allows for safe termination of the simulator operation after a power failure [15]. Electricity meters were connected to the data archiving system to achieve the synchronization of the reading time equal to f = 1 Hz in relation to the simulator operation time. A schematic diagram of the tested installation is shown in Figure 2.

Based on energy consumption measurements, we obtained the total value of energy used by the simulator per flight operation in each propulsion configuration. Each flight consisted of take-off, climb-out, cruise, approach, and taxi. Energy consumption for each propulsion and phase is shown in

Table 1. Energy consumption for each simulated propulsion and phase per flight.

Phase	Energy Consumptions [kWh]
	PE	2PE	VLJ
Take-off	0.208	0.032	0.015
Climb out	0.390	0.266	0.133
Approach	0.262	0.319	0.156
Cruise	0.389	1.954	1.118
Taxi	0.639	1.278	0.639

.

Flight operations were divided into LTO cycle phases. We also needed to perform emission calculations. to achieve the purpose of the article and indicate the advantages of simulation implementation in pilot training in four different scenarios. The scenarios were adopted in accordance with the subsequent stages of ATPL training. Parts of the training were separated into those that could be carried out in simulator conditions and are the next licenses on the way to ATPL. The first scenario (A) assumes that complete pilot training (to ATPL) is undertaken in simulation conditions using a Flight Simulation Training Device (FSTD) [21]. The second scenario (B) assumes that the PPL (A) part of integrated training is performed in real conditions (REAL), and other parts are undertaken in simulation conditions. The third scenario (C) assumes that CPL (A) training is performed in real flight conditions, and other parts (IRME, MCC, MEPL, JOC) are undertaken in simulation flights. The last scenario (D) corresponds to the current situation in pilot flight training: only part of MCC and JOC are performed on flight simulation training devices. The purpose of the division is to compare solutions to check which one will be the most advantageous in terms of energy consumption, emissions, and the aims of the training course. The scenarios and propulsion corresponding to each scenario are shown in

Table 2. Description of scenarios used in research with propulsion division.

Scenario	Training Conditions
	PE	2PE	VLJ
A	FSTD	FSTD	FSTD
B	1/3 REAL, 2/3 FSTD *	FSTD	FSTD
C	REAL	FSTD	FSTD
D	REAL	REAL	FSTD

* About 30.6% of training performed on one-piston engine propulsion concern PPL (A).

.

To compare emissions and energy consumption in the prepared scenarios, the following analyses were need: emission in real flights, fuel consumption in real flights, energy consumption in simulated flights, and emissions arising during energy production.

2.2. Research Methods for Calculation Emission during Training

Assessment of emissions during flight training required calculation of emission during the Landing and Take-off cycle (LTO) and emissions during the cruise phase. This required many assumptions to be made to assess emission from entire flight training. The LTO cycle consists of four phases, which take place under 3000 ft: taxi, take-off, climb-out, and landing. The standard LTO cycle is determined for engines above 26.7 kN of maximum thrust (F), with engine settings and time as follows: taxi 7%F—26 min, take-off 100%F—0.7 min, climb out 85%F—2.2 min, and landing 30%F- 4 min [19,22]. For piston engine aircrafts, the timing of the specific phase and engine power settings are significantly different than the standard LTO cycle. Harmful exhaust gas compounds taken into consideration are: carbon dioxide (CO₂), carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NO_x). To calculate emissions during flight training from piston engine aircrafts, engine settings, duration of the phases, and the emission indexes of piston engine were used based on Aircraft Piston Engine Emissions Summary Report from Federal Office of Civil Aviation (FOCA) [23]. These parameters are presented in

Table 3. Parameters of LTO cycle for piston engine aircraft [23].

LTO Phase	Power Settings [%]	Phase Time [min]	Emission Indexes [g/kg]
			NOx	CO	HC
Take-off	100	0.3	6	818	12.7
Climb out	85	2.5	6	787	12.3
Landing	45	3	2	1055	11.5
Taxi	12	12	0	1123	42.6

.

The emission index for CO₂ emission was adopted as 3.17 kg of CO₂ for 1 kg of fuel [23]. Calculations for cruise phase were made at 65% of engine power and time was estimated based on pilot training programs. Emission indexes of the cruise phase for piston engine are related to the air/fuel mixture and are different for lean and rich mixture, which can be changed by the pilot during the flight to adjust the engine to different flight conditions. Considering this, emission indexes can change depending on the pilot’s technique, but also depends on altitude when atmospheric conditions vary. As the most common technique is “leaning” and the air/fuel mixture in most cases is lean, only emission indexes of lean mixtures have been taken into consideration [23]. Emission indexes for the cruise phase are presented in

Table 4. Emission indexes for cruise phase for piston engine aircraft [23].

Flight Phase	Engine Settings %F	NOx [g/kg]	CO [g/kg]	HC [g/kg]	CO2 [kg/kg]
Cruise	65	23	473	5.4	3.17

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Emissions have been estimated for both one piston engine aircraft and for two piston engines aircraft, which are also used in pilot training. Emission indexes for LTO and cruise phase for two piston engines were assumed to be the same as for one piston engines.

The second part of this analysis was to calculate the value of gas compounds emissions that arise during energy production needed for simulated elements of training. To prepare this type of analysis, electricity emission factors were used. For Poland, factors were chosen from the KOBiZE report [24] (

Table 5. Electricity emission factors for different compounds in Poland.

Compound	Emission Factor for PL [g/kWh]
CO2	685
CO	0.261
NOx	0.456
SOx	0.436

); for different European Union (EU) countries, carbon footprint factors were used [25].

3. Results and Discussion

3.1. Emission Results

Results of the single aerodrome circuit for one piston engine aircraft and results for 1 h of cruise phase are presented in

Table 6. Emission results for single aerodrome circuit.

	NOx [g]	CO [kg]	HC [g]	CO2 [kg]
Take off	1.966	0.268	4.161	1.038
Climb out	16.200	2.125	33.210	8.559
Landing	3.528	1.861	20.286	5.592
Taxi	0	3.073	116.554	8.673
LTO in total	21.694	7.326	174.210	23.862
LTO without taxi	21.694	4.254	57.657	15.189
1 h of cruise phase	1142.64	23.50	268.272	157.486

. As pilot training also includes aerodrome circuits without a taxi phase, the sum of the emissions for a single aerodrome circuit without taxi have also been presented. As can be seen, the greatest NO_x emissions are generated during the climb out phase, when the engine operates at 85% of maximum engine power. For CO, HC, and CO₂, the greatest emissions are generated during the taxi phase, but for CO the values are similar with climb out and landing. Emission of HC during the taxi phase is 3.5 times higher than for climb out and almost 6 times higher than for the landing phase. Emission of CO₂ for taxi and climb out is similar and only 3 kg higher than for landing phase. The lowest emission values were seen during take-off, where the power settings are maximum. For 1 h of cruise phase on lean mixture, the highest emission value is CO₂, which reaches almost 160 kg of CO₂ during 1 h of flight. From toxic exhaust gas compounds, the highest emission is for CO and is equal to 23.5 kg per 1 h of flight. Emission of NOx is about 1 kg per 1 h of flight. Emission of HC is the lowest and is equal to approximately 279 g per 1 h of flight.

Figure 3 presents the results of the NO_x and HC emission assessment generated during complete pilot training on a one piston engine aircraft. The highest emission is seen during the climb out phase, which is approximately 3.5 kg from training on one engine aircraft and about 1.5 from the training on two engines aircraft. The lowest NO_x emission is during the taxi phase and take-off phase. This is due to the short duration of the take-off phase and not every aerodrome circuit including the taxi phase, meaning that the taxi phase is much lower than other phases. HC emission is much higher than NO_x emission due to emission indexes and the way it is formed in the engine during combustion. Minimal NOx emissions are a result of the low combustion temperature in the chamber. The increase in emissions of other compounds is caused by the continuation of processes started upon landing—a reduction in pressure at the inlet to the combustion chamber and depletion of the combustible mixture [26]. The highest HC emission is also from the climb out phase during the training on one engine aircraft and is approximately equal to 7.3 kg; for the same phase, the emission is about 3.2 kg from two engine aircraft. HC emission from training on two engines aircraft is the highest in the taxi phase, but it is almost at the same level from training on one piston engine aircraft (about 6.5 kg).

Figure 4 presents the results of the CO₂ and CO emission assessment generated during complete pilot training. The highest CO and CO₂ emissions are for the climb-out phase for both types of aircrafts, with the highest value of CO₂ equal to about 1900 kg for one piston engine aircraft and about 800 kg for two piston engine aircraft, and CO equal to about 400 kg for one engine and 200 kg for two engine aircraft. CO emission for two engine aircraft is very similar for climb-out, approach, and taxi.

Emissions of NO_x, CO, HC, and CO₂ generated during complete pilot training on one piston engine aircraft and two piston engine aircraft, including the cruise phase, are shown in

Table 7. Emission results for entire pilot training.

	NOx [kg]	CO [t]	HC [kg]	CO2 [t]
One engine	89.563	2.824	38.596	15.422
Two engines	22.310	1.001	17.001	4.743
In total	111.873	3.825	55.597	20.165

. Pilot training in total generates about 112 kg of NO_x, 3.8 tons of CO, 55.6 kg of HC, and 21 tons of CO₂.

Based on data from Table 7, emissions of CO₂, CO, and NO_x in prepared scenarios were calculated. As can be seen in Figure 5a–c, in scenario A, emissions of the chosen gas compounds are near to 0. In scenario D, the emissions are the same as emissions during real flights, which is correct due to the characteristics of this scenario.

In Figure 5d, the reduction of emission gas compounds is shown. As can be seen, if pilot training involves real flight only at the beginning of the exercises (PPL (A)), the emissions will be up to 70–90% smaller than in the current situation (scenario D). Including only two piston engine flights in the simulation part of training (scenario C) can provide a 20–26% reduction of emissions. This can be crucial nowadays when the number of pilots is increasing dynamically and EU policy focuses on reducing carbon footprints. Based on country specific electricity factors included in a 2022 report [25], CO₂ emissions during flight training in each EU country were calculated. This document reports both location-based and market-based emissions. Electricity factors are affected by production mix, which are emissions factors based on the mix of fuels used by power stations in given area. As an example, results of emissions in scenario A are shown in Figure 6.

As can be seen, in Poland, CO₂ emissions related to the production of electricity needed for aviation training are the highest in the entire European Union. Countries close to Poland, such as Germany and Slovakia (marked in orange and yellow in Figure 6), have electricity factors that are 50% (Germany) and 80% (Slovakia) lower than in Poland. This indicates the need to implement solutions to reduce CO₂ emissions in Poland. The use of scenario B or C during aviation training may have a positive impact on emissions from air transport.

3.2. Energy Consumption Results

According to the data shown in Table 1 (energy consumption for each simulated propulsion and phase per one flight), energy consumption in ATPL integrated training resulting from propulsion was calculated. As an example, results for scenario A are shown in

Table 8. Energy consumption in ATPL integrated training.

Phase	Energy Consumptions [kWh]
	PE	2PE	VLJ
Take-off	20.176	0.927	0.160
Climb out	86.19	13.047	1.331
Approach	57.902	15.657	1.598
Cruise	21.23	37.065	6.391
Taxi	35.148	56.663	11.183
Total	220.646	123.359	20.663

.

Based on data shown in Table 2, energy consumption (EC) and fuel consumption (FC) in each scenario were calculated. Using obtained values and the price for 1 kWh of electricity and 1 kg of fuel in Poland, the price of pilot training was calculated. The results are shown in

Table 9. Cost of aviation training in each scenario.

Scenario	EC [kWh]	FC [kg]	Cost [EUR]
A	364.67	0	102.006
B	276.473	1488.68	2919.361
C	220.65	4864.99	9349.428
D	20.66	6361.146	12,149.785

. In Poland, 1 kWh of electricity costs on average PLN 1.2 and 1 kg of aviation fuel (AVGAS 100LL) costs PLN 8.19. Values were converted to EUR (EUR exchange rate on 8 July 2024 was PLN 4.29).

According to data from Table 9, we prepared the plots shown in Figure 7. Referring to cost of training and energy consumption in scenario D (current situation), it can be seen that by implementing scenario C, the cost of ATPL integrated training could be about 23% smaller, and in scenario B as much as 76% smaller. Energy consumption is much higher in scenario A, B, and C than in current situations (scenario D). On the other hand, at this level of energy consumption during flight simulation training, the cost and emissions are significantly smaller than compare to current solutions.

Using LCOE (Levelized Cost of Electricity) average value in EU, we prepared the characteristics shown at Figure 8. LCOE is a measure enabling reliable economic comparison of different sources of electricity. The average cost of different energy sources in EU are as follows: wind EUR 0.23, photovoltaics EUR 0.19, carbon EUR 0.31, and gas EUR 0.34 [27].

As can be seen, there are insignificant differences between prices of electric energy production from the analyzed sources; as such, the cost of training in all scenarios is very similar for each energy source. However, the smallest cost at this moment will be for flight simulator training with energy provided from photovoltaic sources. This solution will also lead to much lower greenhouse gases emissions.

Air traffic operational efficiency has a crucial impact on energy consumption and exhaust emission reduction. The lack of models and tools makes it difficult to numerically calculate and evaluate the effect of new aviation technologies on green operations [28]. In this article, we decided to analyze the energy consumption, CO₂, CO, and NO_x emissions in different scenarios of using flight simulation devices during ATPL integrated training. From these analyses, it was possible to demonstrate the ecological benefits resulting from the use of flight simulator devices, which is also proved in different literature sources [4,5,29]. This topic is significant due to European Union green policy and the lack of this type of calculation and modelling in air transport research, especially in general aviation [1], which mostly concern the pilot training area. There is significant research concerning UAV energy consumption and their flight characteristics, as well as real aircraft emissions [30,31,32,33,34], but energy consumption and the possibilities of flight simulation training devices usage is omitted.

4. Conclusions

Taking into account the analyses carried out, the most favorable scenario for conducting ATPL training in terms of emissions and energy consumption is scenario B. However, in this case, the future pilot only flies 45 h in real conditions, which is only 20% of current practical training. Considering the element of teaching and acquiring piloting skills in the analyses, the most favorable solution is scenario C. With such a solution, the future pilot receives 50% of training (approximately 110 h) in practical conditions and the same amount in simulators. This not only reduces CO₂, NO_x, and HC emissions by 20–25%, but also reduces the cost of training by about 23% (taking into account fuel and energy consumption cost). Scenario A is favorable in terms of emissions and training costs but conducting training entirely in simulator conditions could negatively affect flight safety and pilot qualifications. Based on performed analyses, it can be stated that an increase of FSTD use in pilot training should be a significant consideration in European Union green transport politics. The use of simulators during training, e.g., 5 h for the PPL license, should be obligatory, and not just an option, as it is currently. This approach brings many benefits, especially ecologically. Changing the training program and increasing the use of flight simulators can result in a reduction of CO₂ emissions by up to 70%. The energy consumption needed for training using FSTD depends on the advancement of the device used. However, regardless of the type of Flight Simulator Training Device and the value of energy consumed, CO₂ emissions resulting from the production of the necessary energy are much smaller and depend on the energy production methods in a given country, which are also presented in this article. Taking into account the dynamic development of renewable energy sources, CO₂ emissions in many countries will be negligible and will have a positive effect on reducing the impact of aviation on the environment in the training aspect, which is becoming more and more popular as the number of pilots is constantly increasing.