## 2 Components of Vertiport
### Other Constraints for Vertiport Components  
According to the FAA [14], an approach/departure surface is centered on each approach/departure path, and the approach/departure path starts at the edge of the FATO and slopes upward at 8:1 for a distance of 4000 ft (1219 m) where the width is 500 ft (152 m) at a height of 500 ft (152 m) above the vertiport elevation. The transitional surfaces extend outward and upward from the lateral boundaries of the primary surface and from the approach surfaces at a slope of 2:1, horizontal units and vertical units, respectively, for 250 ft (76 m) measured horizontally from the centerline of the primary and approach surfaces [14].  
When one TLOF supports takeoff and landing in multi-directions, at least 135 degrees is required between two surfaces. The area below the approach/departure surface should  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Components** & **Regulation** & **Dimension** \\ \hline TLOF pad & CD & 18.4 m \\ FATO & 2 \(\times\) CD & 36.8 m \\ Safety Area & 3 \(\times\) CD (1/2 CD added to edge of FATO) & 55.2 m \\ Gate & CD + 10 ft & 21.4 m \\ Taxiway Width & CD + 1/2 CD & 27.6 m \\ \hline \hline \end{tabular}
\end{table}
Table 1: Regulation and dimensions of primary vertiport components that comply with the FAA’s new regulations.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Components** & **Regulation** & **Dimension** \\ \hline TLOF pad & 0.83 \(\times\) CD & 15.272 m \\ FATO & 1.5 \(\times\) CD & 27.6 m \\ Safety Area & FATO + max(3 m, 0.25 \(\times\) CD) & 32.2 m \\ Gate & 1.2 \(\times\) CD & 22.08 m \\ Taxiway Width & 1.5 \(\times\) CD & 27.6 m \\ \hline \hline \end{tabular}
\end{table}
Table 2: Regulation and dimensions of primary vertiport components that comply with new EASA regulations.  
Figure 6: Taxiway width for S-A1.  
be clear of penetrations and obstructions to the approach/departure and transitional surfaces [14]. This is an important standard that should be applied to existing objects and newly installed structures in urban areas. The application of the rules for access routes and transition surfaces and airspace is explained with the figures in Section 3.  
A 60 m separation distance between two FATOs has been recognized as a reference for simultaneous helicopter landings and takeoffs where the courses to be flown do not conflict and where the MTOW of the helicopter does not exceed 3175 kg. This distance can be used as a reference for conducting a safety assessment to determine whether the distance for VTOL capable aircraft should be adapted [15].  
The approach/departure surface and the transitional surface with a 1:8 slope are shown in Figure 7. The dimensions of an omnidirectional obstacle-free volume is shown in Figure 8.  
According to FAA Joint Order 7110.65Z, Section 3-11-5 [18], aircraft can perform simultaneous takeoffs or landings from TLOF pads with more than a 200 ft centerline separation, and the U.S. Army carries out an operation from TLOF pads 150 ft apart [7]. If there is more than one FATO in a heliport, AC 150/5390-2C [10] recommends that multiple aircraft be operated simultaneously by designating the minimum distance between the FATO perimeters as 200 ft (61 m) to separate the perimeters of the two FATOs so that the safety areas do not overlap.  
Figure 8: Dimensions of an omnidirectional obstacle-free volume.  
Figure 7: Approach/departure surface and transitional surface with a 1:8 slope: (a) approach/departure surface; (b) transitional surface.  
In this study, the minimum distance between the FATO perimeters was set to 61 m (200 ft) and the minimum distance between the perimeters of the safety area was set to 42.6 m.