# Disposal and Recycle Economic Assessment for Aircraft and Engine End of Life Solution Evaluation
## 6 Analysis and Result Discussion
### Boeing 737-300 and 747-400 Data Set and Economic Indicators
#### 6.2.1 Economic Indicator Evaluation  
The cost estimations for respective EoL cases are illustrated in Tables 8-10. It is noted that the cost and value are aggregated following the methodology proposed in Section 4. Minor adaptations on specific cost and value items are applied based on actual data availability. For example, the investment cost is the aforementioned residual value related ownership cost. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**D\&R Process**} & \multirow{2}{*}{**Cost Items (\$)**} & **737-300 (Age 20,** & **747-400 (Age 17,** \\  & & **Parking 1 Year)** & **Parking 1 Year)** \\ \hline \multirow{4}{*}{Resale} & Transport & 177,000 & 177,000 \\  & Parking (1 year) & 3600 & 5400 \\  & Maintenance (1 year) & 159,300 & 159,300 \\  & Investment (1 year) & 135,700 & 666,700 \\ \cline{2-4}  & Total & 475,600 & 1,008,400 \\ \hline \multirow{4}{*}{Disassembly \& dismantling} & Labor & 31,860 & 123,900 \\  & Material & 5900 & 11,800 \\  & Transport & 3540 & 11,800 \\ \cline{1-1}  & Scrap & 2360 & 7080 \\ \cline{1-1}  & Equipment & 17,700 & 35,400 \\ \cline{1-1}  & Project management & 7080 & 14,160 \\ \cline{1-1}  & Overhead & 2950 & 5900 \\ \cline{1-1}  & Total & **71,390** & 210,040 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Disposal and recycle costs for 737-300 and 747-400 disposal and recycle cases (2005 USD). \begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{1}{c}{**D\&R Process**} & **Cost Items (\$)** & **B747-400 (Age 20, Parking 3 Years)** \\ \hline \multirow{4}{*}{Resale till age 20} & Transport & 177,000 \\  & Parking (3 years) & 16,200 \\ \cline{1-1}  & Maintenance (3 years) & 199,360 \\ \cline{1-1}  & Investment (3 years) & 2,000,100 \\ \cline{1-1}  & Total & 2,392,660 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Disposal and recycle costs for 747-400 resale till age 20 (2005 USD). A European airline bought the 737 for $23 million ($27 million), and the 747 for $11.3 million ($133 million) [41]. If we set the residual value as 10% of the aircraft price, the residual values for 737-300 and 747-400 are shown in Table 11. The residual value is assumed to be the same for the disassembly & dismantling and the resale options. The salvage values of disassembly & dismantling is the aggregation of the total market value of the dismantled components and materials, which are $3.2 million and 13.2 million for 737-300 and 747-400, respectively. The engine components for 737-300 and 747-400 are estimated to be $0.1 million and $0.2 million, and this should be included in the salvage value. The salvage value of the resale option is assumed to be the current market value of an aircraft when parked one year of vaporization, and it is estimated at $1.7 million and $17.1 million for 737-300 and 747-400 [41], as shown in Table 11.  
Based on the method elaborated in Section 5, the economic indicator for the aforementioned D&R cases can be calculated (see Table 12). It can be seen that the disassembly & dismantling of Boeing 737-300 (\(I_{D\&R}=8.4>1\)) would fully recover the aircraft residual value with extra benefit, and the Boeing 747-400 would only make a profit from the resale (parking 1 year) solution (\(I_{D\&R}=3.8>1\)). By conducting D&R processes when both aircraft are at the same age, it can be seen that the result for the B737-300 remains unchanged, while neither disassembly & dismantling nor resale is economically efficient for the 747-400 aircraft. This is mainly due to the large expense of 3 years parking forthe 747-400 before resale or disassembly & dismantling. Therefore, for an aircraft reaching its EoL, it is better to conduct D&R process sooner. In addition, it is obviously seen that, the older the aircraft, the lower the chance to achieve economic efficiency. Based on \(I_{D\&R}\) measurement, decisions on resale or disassembly & dismantling can be easily made through the comparisons.