## 2 Materials and Methods  
### Bucharest Henri Coanda Airport and Bucharest Baneasa--[PERSON] Approach  
Currently, the only international airport serving the capital of Romania, Bucharest, is Otopeni International Airport (IATA code: OTP, ICAO code: LROP). Figure 2 shows its location in Otopeni City, Ilfov County, 16.5 km north of the center of Bucharest, at 44\({}^{\circ}\)34\({}^{\prime}\)16\({}^{\prime\prime}\) N, 26\({}^{\circ}\)05\({}^{\prime}\)06\({}^{\prime\prime}\) E.  
The Otopeni Airport characteristics are described in Ref. [35]. The airport has two runways, with the following specifications:  
* 08 R-26 L: 3500 m \(\times\) 45 m, 11,484 \(\times\) 148 feet;
* 08 R track with a precision approach, CAT III B;
* 26 L track with a precision approach, CAT II;
* 08 L-26 R: 3500 m \(\times\) 45 m, 11,484 \(\times\) 148 feet;
* 08 L track with a precision approach, CAT III A;
* 26 R track with a precision approach, CAT II;
* Total airport area: 605 ha. The data presented in Figure 3 illustrates the statistics on the movements and passenger numbers at Otopeni Airport [35]. Figure 2: Location of Otopeni airport [35]. Prior to 2020, which marked the outbreak of the COVID-19 pandemic, there had been a consistent upward trend in air traffic. This growth prompted proposals for airport expansion or even for the construction of a new airport in the vicinity of the capital to accommodate the surge in aircraft flow. However, a more cost-effective and straightforward alternative is to utilize Baneasa Airport. Baneasa Airport Characteristics  
Bucharest Baneasa-Aurel Vaicu International Airport (IATA code: BBU, ICAO code: LRBS) is located in the north of Bucharest Municipality, 8.5 km from the center of Romania's capital, and in the immediate vicinity of the towns of Otopeni, Voluntari, and Afumati. The airport's geographical position is at Lat. 44\({}^{\circ}\)30.2\({}^{\prime}\) N, Long. 26\({}^{\circ}\)02.0\({}^{\prime}\) E.  
Technical details include aerodrome elevation: 91 m; reference temperature: 24.9 \({}^{\circ}\)C; magnetic variation: 29\({}^{\prime}\) E (1966); transition altitude: 1200 m; runway: 3200 m (07/25); apron: 22 spots; navigation aids: ILS, SRE, PAPI, and PAR; rescue and firefighting equipment: ICAO category 8; operational capacity: 15 aircraft movements/hour; passenger processing capacity: 40 passengers/flow/hour [36]. The airport is surrounded by residential areas in the south, east, southwest, and northeast directions, and by commercial and industrial zones in the north and west areas. The airport's main activity concerns the provision of services, operation, maintenance, repair, development, and the modernization of assets in its ownership or concession to ensure good conditions for the arrival, departure, and ground handling of aircraft from national and/or international traffic, while providing airport services for the transit of passengers, goods, and mail, as well as services of national public interest. The airport serves the following aircraft: the Airbus 319, Airbus 310, Airbus 320, Boeing B734, and Boeing B733. As shown in Figure 4, Baneasa Airport is relatively small. Figure 4: Location of Baneasa Airport. Figure 3: Number of passengers (**a**) and number of air traffic movements (**b**) at Otopeni Airport. At present, Baneasa Airport is used for international flights featuring smaller aircraft and has substantially lower traffic volumes compared to Otopeni Airport, as substantiated by the data presented in Figure 5[35]. As shown in Figure 6, these two airports are located close to each other and could serve the same region. As can be seen in Figure 4, above, Baneasa Airport's runway is very close to nearby houses, and the nearest houses are only 300 m away. Consequently, using it for larger, more powerful aircraft or in high-traffic situations is almost impossible.