Originally Posted by
PHLviaUS
Yes, they do. The DOT on-time reporting counts all flights that arrive 15 or more minutes behind schedule as "late" regardless of cause. The only original exemption for mechanicals was removed several years ago.
All things being the same, wouldn't weather and ATC affect all traffic leaving that facility? I would assume these delays cancel each other out because on that given day all carriers would be experiencing the same delays from that point of origin.