select DivTailNums,
arrayConcatString(DivTailNums, DivTailNums) AS concatIds
from airlineStats
WHERE arraylength(DivTailNums) >= 2
limit 5N7713A,N7713A
N7713A,N7713A,N7713A,N7713A
N344AA,N344AA
N344AA,N344AA,N344AA,N344AA
N344AA,N344AA
N344AA,N344AA,N344AA,N344AA
N7713A,N7713A
N7713A,N7713A,N7713A,N7713A