7 minute connection in BWI
 

I was looking up a LAS-EWR to check the flight status but didn't know the flight number, when I looked at the timetable to find the flight number I noticed this connection

CO1582 LAS 1255a CLE 753a 738
CO2542 CLE 900a BWI 1018a E145
CO2796 BWI 1025A EWR 1128a E145

Is this a legal connection? Don't you have to be at the gate 10 minutes before departure?

What shows on the timetable does not mean you'll actually get to book those flights. The timetable has shown flights with connection time of 0 minutes.

Me thinks Co might use the same E-145 CLE-BWI-EWR. This would be a great route to collect some extra segments methinks.

It isn't possible for CO to turn around an ERJ in seven minutes. Twenty minutes, perhaps, but not seven. Under the best of circumstances and even in the absence of a full load of passengers, it would take seven minutes just to board the aircraft, let alone the time required to deplane the inbound passengers and perform any aircraft service. If they use the same ERJ for CLE-BWI-EWR, it is not on the itinerary cited by the OP.