Life Stories

Does sun angle affect air traffic patterns?

Dear Tom,

I live in River Forest and there seems to be a heavier aircraft flight load over me in the early morning. Is this because of the sunlight angle in the morning in the winter?

Wilson Montgomery

Dear Wilson,

A morning “aviation rush hour” does occur. The busy period, starting around 6:30 a.m., is a peak time for business travel. A second peak period is between about 2 and 7 p.m. These are not related to sun angle, however. Wind direction is the key variable in deciding which runways are used for landing, not sunlight. Pilots must be able to direct their aircraft into any existing wind for the safest landing. Only on rare occasion and when a visual approach is involved might a landing be shifted to a different runway because of the sun. Therefore, there is not much seasonal change as a direct result of sunlight.