Chapter 3: Data
3.3. Descriptive statistics
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airline serving the destination and multiplied by the number of passengers each aircraft can carry to obtain the number of passengers per flight
𝑃𝑎𝑠𝑠𝑒𝑛𝑔𝑒𝑟𝑠 = 𝑙𝑜𝑎𝑑 𝑓𝑎𝑐𝑡𝑜𝑟 ×𝑎𝑖𝑟𝑐𝑟𝑎𝑓𝑡 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦.
As this study deals primarily with gate-to-gate data, the ground time is calculated as the time an aircraft arrives at the gate and when it exits the gate again for a departure.
This definition does not consider time an aircraft spends on the ground when leaving the gate for a departure or taxiing (moving) to a resting station or maintenance hangar. Although ground times are not publicly available, flights were matched by aircraft registrations to calculate turnaround times.
Turnaround times
Turnaround times up to eight hours were considered scheduled. Turnaround times over eight hours were considered as long turnarounds and assumed maintenance or overnight stays which could absorb flight delays if necessary (Baumgarten, 2014;
Cook & Tanner, 2008). This provides enough time for A-checks, the shortest maintenance check that happen up to every 600 hours for up to 10 hours per check and controls for unexpected maintenance which has a greater propagation effect as noted earlier and by Kafle and Zou (2016). Even though there are certain airlines that schedule longer ground times, (for example Emirates has a schedule ground time of 7 hours), we assume that these longer ground times are calculated to meet airlines’
need elsewhere in their network.
𝑇𝑢𝑟𝑛𝑎𝑟𝑜𝑢𝑛𝑑𝑠𝑐ℎ𝑒𝑑𝑢𝑙𝑒𝑑 = 𝑆𝑇𝐷 − 𝑆𝑇𝐴 𝑇𝑢𝑟𝑛𝑎𝑟𝑜𝑢𝑛𝑑𝑎𝑐𝑡𝑢𝑎𝑙 = 𝐴𝑇𝐷 − 𝐴𝑇𝐴
3.3. Descriptive statistics
Figure 3 provides a snapshot of the number of flights operated at Taoyuan Airport during the period 2011-2016. The airport has experienced an increase in flights for the period covered in this study and thus allows us to investigate the effect of an increase in traffic on on-time performance.
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Figure 3: Growth of passengers at Taoyuan Airport
There are 53 airlines included in this study. As mentioned before, Taoyuan Airport is the base for various airlines and their subsidiaries (grouped together) as displayed in Table 2. Although some airlines, such as TransAsia and VAir, have gone bankrupt during the period studied they were still included for illustrative purposes. Bases can take the form of a hub and spoke or of a focus city and are used to operate fifth freedom right flights. Unsurprisingly, these airlines make up the most amount of flights taking off or landing at Taoyuan Airport as displayed in Table 3.
Table 2: Summary of airlines based at Taoyuan Airport
Airline Base type Airline type
China Airlines, Mandarin Airlines Hub Full service carrier EVA Air, UNI Air Hub Full service carrier Far Eastern Air Transport Hub Full service carrier
TransAsia Hub Full service carrier
Tiger Air Taiwan Hub Low cost carrier
V Air Hub Low cost carrier
Cathay Pacific Focus Full service carrier
THAI Airways Focus Full service carrier
Scoot Focus Low cost carrier
0 10 20 30 40 50
2011 2012 2013 2014 2015 2016
Total passengers (in millions)
Year
Total Passengers
Total Passengers
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Table 3: Largest airlines at Taoyuan by flights
Airline Arrival Departures Total
China Airlines 70,553 70,759 141,312
EVA Air 60,089 60,142 120,231
Cathay Pacific 22,133 22,173 44,306
TransAsia 11,528 11,999 23,527
China Southern 10,311 10,328 20,639
China Eastern 9,402 9,377 18,779
Tiger Air Taiwan 6,803 6,898 13,701
Air China 6,579 6,612 13,191
Japan Airlines 5,440 5,460 10,900
Mandarin Airlines 5,214 5,251 10,465
In this study, 113 cities are included that airlines operate to and from Taoyuan.
Taoyuan has flights to all continents except Africa and South America. Being based in Asia, that the top airports served from Taoyuan are all based in Asia as shown in Table 4. Hong Kong is the top most served airport not only due to its economic and political ties to Taiwan but also its proximity to the airport which allows for high frequencies.
Other Asian economic hubs such as Tokyo and Singapore also feature in the top 5.
Table 4: Largest airports operated to from Taoyuan by flights
City Arrival Departure Total
Hong Kong 43,738 44,109 87,847
Osaka 18,600 18,797 37,397
Tokyo Narita 18,516 18,631 37,147
Macau 12,014 12,335 24,349
Singapore 11,433 11,398 22,831
Seoul Incheon 11,200 11,285 22,485
Shanghai 11,030 11,354 22,384
Bangkok 8,646 8,721 17,367
Manila 7,436 7,482 14,918
Ho Chi Minh 6,464 6,495 12,959
Taoyuan’s routes are relatively competitive as 73 routes have more than one airline flying both directions as shown in Table 5. Seven routes have more than five airlines competing for market share.
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Table 5: Most competitive routes operated from Taoyuan
City / Airport Airlines Tokyo Narita 10 Shanghai Pudong 8
Seoul Incheon 7
Osaka 7
Singapore 7
Manila 5
Hong Kong 5
When looking at LCC’s, only 12.71% of Taoyuan’s flights are from LCC as shown in Table 6. In terms of airline alliances shown in Table 7, the two main hub airlines, China Airlines and EVA Air’s alliances are represented by SkyTeam and Star Alliance respectively. This is an indication of alliance coordination and cooperation mentioned by Yimga (2017). Furthermore, only half of LCC’s flights belong to the Value Alliance, the only low cost alliance3 to be represented at Taoyuan which also has the lowest alliance share. This shows that Taoyuan is still dominated by FSC’s. For the purposes of this study however, the airlines and alliances represented are sufficient.
Table 6: Comparison of FSC and LCC flights at Taoyuan
Arrival Departure Total Share Full Service Carriers 253,881 255,103 508,984 87.29%
Low Cost Carriers 37,001 37,118 74,119 12.71%
Table 7: Comparison of airline alliance flights at Taoyuan
Alliance Arrival Departure Total Share
SkyTeam 102,275 102,473 204,748 35.11%
Star Alliance 79,435 79,533 158,968 27.26%
None 58,919 59,758 118,677 20.35%
oneworld 32,239 32,307 64,546 11.07%
Value Alliance 18,014 18,150 36,164 6.20%
Flights are evenly distributed between all weekdays, peaking somewhat between Saturdays to Mondays. The flight distribution throughout the day displays different behavior for arrival and departure flights. Departure flights display a morning rush
3 Eastar Jet belongs to the UFly Alliance, another low cost alliance. However, since it is the only airline of that alliance represented, it is meaningless to study the alliance’s operations at Taoyuan.
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hour between 6:00 and 8:00 whereas the busiest time for arrivals would be 21:00 at night. The two peaks may be indicative of Taoyuan’s hub airlines, where most of their flights depart in the mornings to their respective spoke cities and arrive back home in the evening in time for turnaround times, ideal for overnight maintenance in time for departure the next day.
Figure 4: Number of flights operated per weekday
Figure 5: Number of flights operated per hour group 0
10 000 20 000 30 000 40 000 50 000 60 000 70 000 80 000 90 000
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Average daily passengers
Weekday
Departures
Arrivals
0 5 000 10 000 15 000 20 000 25 000 30 000 35 000
H00 H01 H02 H03 H04 H05 H06 H07 H08 H09 H10 H11 H12 H13 H14 H15 H16 H17 H18 H19 H20 H21 H22 H23
Departures Arrivals
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Figure 6: Number of flights operated by the top 20 airlines at Taoyuan Airport