INVESTIGATION OF THE EFFECT OF SNOWFALL ON THE FLIGHTS IN TURKEY

INVESTIGATION OF THE EFFECT OF SNOWFALL ON THE FLIGHTS IN TURKEY A. ÇAKIN 1,*, İ. CEYHAN 1, V. YAVUZ 1, E. T. ÖZDEMİR 1,2, C. TEMİZ 1, A. DENİZ 1 1 Istanbul Technical University, Faculty of Aeronautics and Astronautics, Department of Meteorological Engineering, Maslak, 34469 Istanbul Turkey 2 General Directorate of Meteorology, Atatürk Meteorology Office, Yeşilköy, Istanbul, Turkey * cakina@itu.edu.tr Abstract Air transport, has started to become more popular in the transportation sector in recent years. People can save both time and money by using this type of transportation. That is why even a minute deviation of the departure and arrival time of an airplane will lead to affect other flights, and it will be reflected adversely to the people. The most important factors that affect the departure and arrival of the airplane is technical and meteorological conditions. While technical requirements can be solved with appropriate interventions, meteorological conditions may cause the cancellation of the flights and deviation with hours or even days. A flight to take place under appropriate conditions, not just from the port, the destination is also required to be eligible. s to happen smoothly, the visibility of the runway, cloud base height, icing, wind speed and direction, fog, snowing and a lot of meteorological factors must be appropriate with required standards. These standards vary according to the location of each airport. In this study, snowfall, a significant meteorological factor, were examined how affect the national and international airports in Turkey and is that caused flight cancellations at any airports in recent time. According to preliminary data obtained, between the dates 05/01/2015-08/01/2015, there are so many cancellations and delays happened at many airports because of snowfall. Keywords: Snowfall, airports, flight, Turkey INTRODUCTION Air transportation is becoming more important every year. People prefer airways instead of the railways or highways because of recovery time. Also, people can save both time and money by using this type of transportation. So, the important thing is that even a minute deviation of the departure and arrival time of an airplane will lead to affect other flights, and it will be reflected adversely to the people. The most important factors that affect the departure and arrival of the airplane is technical and meteorological conditions. While technical requirements can be solved with appropriate interventions, meteorological conditions may cause the cancellation of the flights and deviation with hours or even days. A flight to take place under appropriate conditions, not just from the port, the destination is also required to be eligible. There are many factors which must be appropriate with required standards such as visibility

of the runway, cloud base height, icing, wind speed and direction, windchill, fog, snowing and many meteorological factors must be appropriate with required standards. These standards vary according to the location of each airport. In this study, snowfall, a significant meteorological factor, were examined how affect the national and international airports in Turkey and is that caused flight cancellations at any airports in recent time. According to preliminary data obtained, between the dates 05/01/2015-08/01/2015, there are so many cancellations and delays happened at many airports because of snowfall. This study stated that cancellation of 101 flights has led to approximately 18 thousand passengers aggrieved and accordingly there are material and spiritual losses for THY Company. METHOD In this study, analysis of METARs, TAFs and Synoptic Codes are investigated for flights cancellation of Turkish Airlines which also known as common companies in aviation sector. Cancelled flights at international airports in Turkey are shown in the following list as a result of occur snow held between 7-8 January 2015. Turkish Airlines has cancelled 165 flights in totally because of snowfall in 7-8 January 2015. This study just involves the examination about the cancellation of 101 flights occurred in international airports in Turkey. Informations for International s in Turkey LOCATION ICAO IATA AIRPORT NAME Adana LTAF ADA Adana Şakirpaşa LTAC ESB a Antakya LTAK HTY Hatay Antalya LTAI AYT Antalya Bodrum LTFE BJV Milas-Bodrum Bursa LTBR YEI Bursa Yenişehir Dalaman LTBS DLM Dalaman Erzurum LTCE ERZ Erzurum Eskişehir LTBY AOE Eskişehir Anadolu Gaziantep LTAJ GZT Gaziantep İstanbul LTBA IST İstanbul Atatürk İstanbul LTFJ SAW LTBJ ADB Kayseri LTAU ASR Kayseri Konya LTAN KYA Konya Kütahya LTBZ KZR Kütahya Zafer

Malatya LTAT MLX Malatya Nevşehir LTAZ NAV Nevşehir Kapadokya Samsun LTFH SZF Samsun Çarşamba Şanlıurfa LTCS GNY Şanlıurfa GAP Trabzon LTCG TZX Trabzon Visual range is determined by an observer and defined as the maximum distance at which an object or low intensity light can be distinguished. Visual range and visibility are used here interchangeably. Runway visual range (RVR), in aviation meteorology, is the distance over which a pilot of an aircraft on the centreline of the runway can see the runway surface markings delineating the runway or identifying its centre line. METAR is a format for reporting weather information. A METAR weather report is predominantly used by pilots in fulfillment of a part of a pre-flight weather briefing, and by meteorologists, who use aggregated METAR information to assist in weather forecasting. TAF (terminal aerodrome forecast or terminal area forecast) is a format for reporting weather forecast information, particularly as it relates to aviation meteorology. TAFs are issued every 6 hours such as 0000,0600,1200,1800 UTC, and generally apply to a 24 or 30-hour period, and an area within approximately five statute miles from the center of an airport runway complex. TAFs complement and use similar encoding to METAR reports. They are produced by a human forecaster based on the ground. For this reason there are considerably fewer TAF locations than there are airports for which METARs are available. TAFs can be more accurate than Numerical Weather Forecasts, since they take into account local, small-scale, geographic effects. SYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. CAVOK is an abbreviation for And Okay, indicating no cloud below 5,000 ft (1,500 m) or the highest minimum sector altitude and no cumulonimbus or towering cumulus at any level, a visibility of 10 km (6 mi) or more and no significant weather. Atmospheric icing occurs when water droplets in the atmosphere freeze on objects they contact. This can be extremely dangerous to aircraft, as the built-up ice changes the aerodynamics of the flight surfaces, which can increase the risk of a subsequent stalling of the airfoil.

and s Of Cancelled s Table No 1 7.01.15 TK2014 2 7.01.15 TK2015 3 7.01.15 TK2032 4 7.01.15 TK2033 5 7.01.15 TK2036 6 7.01.15 TK2037 7 7.01.15 TK2038 8 7.01.15 TK2039 9 7.01.15 TK2122 10 7.01.15 TK2123 11 7.01.15 TK2138 12 7.01.15 TK2139 13 7.01.15 TK2150 14 7.01.15 TK2151 15 7.01.15 TK2170 İstanbul 17:25 (ASR) Kayseri 19:30 İstanbul 06:55 (KYA) Konya 08:55 İstanbul 13:45 (KYA) Konya 15:45 İstanbul 17:55 (KYA) Konya 19:55 İstanbul 07:00 a 09:00 İstanbul 10:00 a 11:50 İstanbul 13:00 a 15:00 18:00 Of (ASR) Kayseri 18:45 10000 3300 İstanbul 21:00 10000 3000 (KYA) Konya 08:10 8000 3000 İstanbul 10:15 6000 2500 (KYA) Konya 15:00 500 300 İstanbul 17:05 2000 1400 (KYA) Konya 19:10 4000 300 İstanbul 21:20 10000 3000 a 08:05 10000 3500 İstanbul 10:05 7000 2500 a 11:05 10000 3500 İstanbul 12:55 3500 2400 a 14:05 10000 4000 İstanbul 16:05 2000 2400 19:05 10000 3500

16 7.01.15 TK2171 17 7.01.15 TK2220 18 7.01.15 TK2221 19 7.01.15 TK2320 20 7.01.15 TK2321 21 7.01.15 TK2334 22 7.01.15 TK2335 23 7.01.15 TK2454 24 7.01.15 TK2455 25 7.01.15 TK2470 26 7.01.15 TK2471 27 7.01.15 TK2480 28 7.01.15 TK2908 İstanbul a 20:00 İstanbul 06:00 (GZT) Gaziantep 08:30 İstanbul 11:00 12:50 İstanbul 18:00 20:00 İstanbul 06:30 (ADA) Adana 08:45 İstanbul 17:00 (ADA) Adana 19:15 İstanbul 20:30 İstanbul 12:55 Of a İstanbul 21:05 10000 4000 (GZT) Gaziante p 07:40 10000 200 İstanbul 10:25 6000 2500 Mendere s 12:05 10000 3000 İstanbul 13:55 3000 2400 Mendere s 19:05 10000 3000 İstanbul 21:05 10000 4000 (ADA) Adana 08:00 10000 3500 İstanbul 10:25 6000 2600 (ADA) Adana 18:30 10000 3500 İstanbul 20:55 6000 2800 (ADA) Adana 22:00 10000 3500 Mendere s 13:55 10000 3000

29 7.01.15 TK2909 30 7.01.15 TK2914 31 7.01.15 TK2915 32 7.01.15 TK2922 33 7.01.15 TK2923 34 7.01.15 TK2964 35 7.01.15 TK2965 36 7.01.15 TK2976 37 7.01.15 TK2978 38 7.01.15 TK2979 39 7.01.15 TK2981 40 7.01.15 TK7242 14:40 İstanbul 19:00 20:50 İstanbul 07:00 (AYT) Antalya 08:55 İstanbul 07:30 a 09:15 İstanbul 18:15 İstanbul 19:15 a 20:30 a 21:15 İstanbul 08:00 Of İstanbul 15:40 700 600 Mendere s 15:40 10000 3000 İstanbul 21:50 10000 3500 (AYT) Antalya 08:10 10000 3000 İstanbul 10:05 700 900 a 08:30 10000 3500 İstanbul 10:15 R06/1200 R24/1500 1600 a 19:20 10000 3500 a 20:20 10000 3500 İstanbul 21:30 3200 1200 İstanbul 22:15 3200 1200 a 09:00 10000 3500

41 7.01.15 TK7243 42 7.01.15 TK7284 43 7.01.15 TK7285 44 7.01.15 TK7296 45 7.01.15 TK7297 46 8.01.15 TK2116 47 8.01.15 TK2117 48 8.01.15 TK2010 49 8.01.15 TK2011 50 8.01.15 TK2630 51 8.01.15 TK2631 52 8.01.15 TK2032 53 8.01.15 TK2033 54 8.01.15 TK2458 a 09:00 İstanbul 08:45 (KYA) Konya 10:25 İstanbul 18:30 (ASR) Kayseri 20:15 İstanbul 06:00 a 08:00 İstanbul 06:35 (ASR) Kayseri 08:45 İstanbul 06:40 (MLX) Malatya 09:15 İstanbul 06:55 (KYA) Konya 08:55 İstanbul 08:50 İstanbul 10:00 Of R06/1200 R24/P1500 1600 (KYA) Konya 09:55 2500 3500 İstanbul 11:35 10000 2700 (ASR) Kayseri 19:45 8000 3300 İstanbul 21:30 R06/0500 R24/P1500 1200 a 07:05 10000 4000 İstanbul 09:05 7000 3100 (ASR) Kayseri 08:00 10000 1000 İstanbul 10:15 7000 3000 (MLX) Malatya 08:20 10000 2000 İstanbul 11:00 6000 3000 (KYA) Konya 08:10 10000 4000 İstanbul 10:15 6000 3000 (ADA) Adana 10:25 10000 3600

55 8.01.15 TK2459 56 8.01.15 TK2142 57 8.01.15 TK2143 58 8.01.15 TK2320 59 8.01.15 TK2321 60 8.01.15 TK2012 61 8.01.15 TK2013 62 8.01.15 TK2152 63 8.01.15 TK2453 64 8.01.15 TK2162 65 8.01.15 TK2163 66 8.01.15 TK2170 67 8.01.15 TK2171 68 8.01.15 TK2334 (ADA) Adana 11:10 İstanbul 11:00 a 13:00 İstanbul 11:00 12:50 İstanbul 12:55 (ASR) Kayseri 15:05 İstanbul 14:00 a 06:45 İstanbul 16:00 a 18:00 İstanbul 18:00 a 20:00 İstanbul 18:00 Of İstanbul 12:50 6000 2500 a 12:05 10000 4000 İstanbul 14:05 10000 3000 Mendere s 12:05 10000 3000 İstanbul 13:55 9000 3000 (ASR) Kayseri 14:20 10000 2100 İstanbul 16:35 8000 2300 a 15:05 10000 4000 İstanbul 08:25 10000 3400 a 17:05 10000 4000 İstanbul 19:05 10000 2500 a 19:05 10000 4000 İstanbul 21:05 10000 3000 Mendere 19:05 10000 CAVOK

s Of 69 8.01.15 TK2335 70 8.01.15 TK2008 71 8.01.15 TK2009 72 8.01.15 TK2182 73 8.01.15 TK2183 74 8.01.15 TK2116 75 8.01.15 TK2117 76 8.01.15 TK2010 77 8.01.15 TK2011 78 8.01.15 TK2630 79 8.01.15 TK2631 80 8.01.15 TK2032 81 8.01.15 TK2033 82 8.01.15 TK2458 20:00 İstanbul 19:40 (NAV) Nevşehir Kapadokya 22:00 İstanbul 21:00 a 23:00 İstanbul 06:00 a 08:00 İstanbul 06:35 (ASR) Kayseri 08:45 İstanbul 06:40 (MLX) Malatya 09:15 İstanbul 06:55 (KYA) Konya 08:55 İstanbul 08:50 İstanbul 21:05 10000 3000 (NAV) Nevşehir Kapadok ya 21:05 10000 4000 İstanbul 23:25 10000 3300 a 22:05 10000 CAVOK İstanbul 00:05 10000 3900 a 07:05 10000 4000 İstanbul 09:05 7000 3100 (ASR) Kayseri 08:00 10000 1000 İstanbul 10:15 7000 3000 (MLX) Malatya 08:20 10000 2000 İstanbul 11:00 6000 3000 (KYA) Konya 08:10 10000 3500 İstanbul 10:15 6000 3000 (ADA) Adana 10:25 10000 3600

83 8.01.15 TK2459 84 8.01.15 TK2142 85 8.01.15 TK2143 86 8.01.15 TK2320 87 8.01.15 TK2321 88 8.01.15 TK2012 89 8.01.15 TK2013 90 8.01.15 TK2152 91 8.01.15 TK2453 92 8.01.15 TK2162 93 8.01.15 TK2163 94 8.01.15 TK2170 95 8.01.15 TK2171 96 8.01.15 TK2334 (ADA) Adana 11:10 İstanbul 11:00 a 13:00 İstanbul 11:00 12:50 İstanbul 12:55 (ASR) Kayseri 15:05 İstanbul 14:00 (ADA) Adana 06:45 İstanbul 16:00 a 18:00 İstanbul 18:00 a 20:00 İstanbul 18:00 Of İstanbul 12:50 6000 2500 a 12:05 10000 4000 İstanbul 14:05 10000 3000 Mendere s 12:05 10000 3000 İstanbul 13:55 9000 3000 (ASR) Kayseri 14:20 10000 2100 İstanbul 16:35 8000 2300 a 15:05 10000 4000 İstanbul 08:25 10000 3400 a 17:05 10000 4000 İstanbul 19:05 10000 2500 a 19:05 10000 4000 İstanbul 21:05 10000 3000 Mendere 19:05 10000 CAVOK

s Of 97 8.01.15 TK2335 98 8.01.15 TK2008 99 8.01.15 TK2009 100 8.01.15 TK2182 101 8.01.15 TK2183 20:00 İstanbul 19:40 (NAV) Nevşehir Kapadokya 22:00 İstanbul 21:00 a 23:00 İstanbul 21:05 10000 3000 (NAV) Nevşehir Kapadok ya 21:05 10000 4000 İstanbul 23:25 10000 3300 a 22:05 10000 CAVOK İstanbul 00:05 10000 3900 CONCLUSIONS base height and visibility are analyzed through METARs and TAFs codes. The results are shown that values below 5000 meter in many airports. Even this, flights cancelled due to this value reach to below 1500 meter with the assumption that prevent flight during snowfall in some of the airports. Based on the research result shown another cause of cancelled flights, icing consisting of winds after snowfall has been determined. s was cancelled that might occur during icing formed in the landing runway at many airports may be the trigger of the huge accident.

This study stated that cancellation of 101 flights has led to approximately 18 thousand passengers aggrieved and accordingly there are material and spiritual losses for THY Company. Finally, night at January 8tt, THY employee worked on all planes for de-icing. Also, they have taken precautions for next flights. As it can see at the table, most of the cancellations are occurred at Istanbul Atatürk. After these days, the flights back to normal because of de-icing operations and more better weather conditions.

REFERENCES New Aviation Meteorology, Aviation Meteorology Course Document http://www.turkishairlines.com/tr-tr/kurumsal/basinodasi/duyurular/duyuru/kotu-hava-kosullari-nedeniyle-iptal-olan-seferler http://www.ogimet.com/metars.phtml http://www.hurriyet.com.tr/gundem/27917626.asp http://www.cumhuriyet.com.tr/haber/turkiye/178971/thy_seferleri_iptal.html https://www.wmo.int/pages/index_en.html http://www.noaa.gov/ http://wxmaps.org/pix/euro.fcst.html