For the flight with the tail number 'N702SK', which air carrier does it belong to?
tail number refers to TAIL_NUM; TAIL_NUM = 'N702SK';
SELECT T2.Description FROM Airlines AS T1 INNER JOIN `Air Carriers` AS T2 ON T1.OP_CARRIER_AIRLINE_ID = T2.Code WHERE T1.TAIL_NUM = 'N702SK' GROUP BY T2.Description