Originally Posted by
flyer703
73G (UA 551 - IAH) took off today at 5:56am (not on your list but same thing)
The 73G is a 737-700 and it is unrestricted up to its maximum weights. That's why it wasn't on the list.
The list only included aircraft that UAL operates. Other aircraft, such as AA's and DL's MD80/90 series, may also have restrictions.