Years ago I booked a 3pm DCA - EWR departure for a 9:45 EWR - LHR flight. Not realizing what I had done being a newbie with DCA - EWR connections - the 3 was delayed and ended up on Virgin - which was ok - at least made it.

The agent at the Presidents Club put it best:

The 3pm leaves at 5pm, the 5pm leaves at 7pm, the 7pm is cancelled and the 9 always goes as the plane comes from CLE.

He suggests on ANY international connections through EWR you be on the 11am - the 12:59 to EWR is even risky. Forget the 3pm or later... for sure you will probably miss your connection.

I love the CLE-LHR flight... CLE is usually never delayed out of DCA. I wish they would make it a permanent flight.