My parents will be flying the UA daytime flight to LHR in a few days. They have no elite status and are flying in Y (no, I didn't have enough miles to upgrade them. ). My dad wanted to get to the airport at about 7:00 for their 9:00 (or is it 9:30?) flight? I thought it would be too close a call and recommend they get there no later than 6:30 or even 6:00. Does anyone here think 7:00 is reasonable, or should they allow more time? I haven't been to IAD that early in a few years, so don't have a good idea of how it is there anymore.

Thanks!!