## 2 Materials and Methods
### 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 (CO\({}_{2}\)), 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.  
The emission index for CO\({}_{2}\) emission was adopted as 3.17 kg of CO\({}_{2}\) 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  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Scenario**} & \multicolumn{4}{c}{**Training Conditions**} \\ \cline{2-5}  & **PE** & **2 PE** & **VIJ** \\ \hline A & FSTD & FSTD & FSTD \\ \hline B & 1/3 REAL, 2/3 FSTD * & FSTD & FSTD \\ \hline C & REAL & FSTD & FSTD \\ \hline D & REAL & REAL & FSTD \\ \hline \hline \end{tabular}  
* About 30.6% of training performed on one-piston engine propulsion concern PPL (A).  
\end{table}
Table 2: Description of scenarios used in research with propulsion division.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**LTO Phase**} & **Power Settings [\%]** & **Phase Time [min]** & \multicolumn{3}{c}{**Emission Indexes [g/kg]**} \\ \cline{3-5}  & **Power Settings [\%]** & **Phase Time** & **NOx** & **CO** & **HC** \\ \hline Take-off & 100 & 0.3 & 6 & 818 & 12.7 \\ \hline Climb out & 85 & 2.5 & 6 & 787 & 12.3 \\ \hline Landing & 45 & 3 & 2 & 1055 & 11.5 \\ \hline Taxi & 12 & 12 & 0 & 1123 & 42.6 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Parameters of LTO cycle for piston engine aircraft [23].  
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.  
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); for different European Union (EU) countries, carbon footprint factors were used [25].