  Solar flare is one of the severest solar activities on the sun, and it has
many important impacts on the near-earth space. It has been found that flight
arrival delays will increase during solar flare. However, the detailed
intrinsic mechanism of how solar flares influence the delays is still unknown.
Based on 5-years huge amount of flight data, here we comprehensively analyze
the flight departure delays during 57 solar flares. It is found that the
averaged flight departure delay time during solar flares increased by 20.68%
(7.67 min) compared to those during quiet periods. It is also shown that solar
flare related flight delays reveal apparent time and latitude dependencies.
Flight delays during dayside solar flares are more serious than those during
nightside flares, and the longer (shorter) delays tend to occur in the lower
(higher) latitude airport. Further analyses suggest that flight delay time and
delay rate would be directly modulated by the solar intensity (soft X-ray flux)
and the Solar Zenith Angle. For the first time, these results indicate that the
communication interferences caused by solar flares will directly affect flight
departure delay time and delay rate. This work also expands our conventional
understandings to the impacts of solar flares on human society, and it could
also provide us with brand new views to help prevent or cope with flight
delays.
