When traveling on a domestic flight in the US, how early is it recommended to get to the airport before the flight is scheduled to leave? What about international flights leaving from the US? Are there general rules for times of day or days of the week when airports tend to be busier and it would be wise to arrive earlier?
The general rule of thumb is that one is supposed to arrive
That said, I've never found that rule to be terribly useful because it doesn't take into account size of the airport, day of the week, or anything like that.
Personally, I also find the times to be a little bit excessive - I figure on
I've never missed a plane (although once, going to Bermuda, they had to hold a plane for me!)
As an example, iad (Dulles Airport) - On a Sunday evening, I could make it from car to gate in under 30 minutes, whereas on a Monday morning, I needed a minimum of 60.
In general -
The key variable is determining how early you should arrive is the security line. You can get a decent grip on this by checking out MyTSA's website.
There is no single answer. You need to allow time for a number of individual things, which may or may not apply to you. Between the moment you drive on to the airport property and the moment you reach the boarding gate, you should allow for:
So best case, I can get out of a cab and be at the gate 10 minutes later. (In a tiny airport, checked in online, status, no luggage.) Someone else with no status, a car to park, a bag to check, and no fast passes into express lines might need hours to cover the same distance if the airport was very busy. At the end of all that time, you need to reach your gate within the time specified by the airline. There may also be deadlines for checkin or baggage drop-off - these should be on the airline web site. For example you might need to get to the gate 30 min before the flight leaves, but drop off your baggage 60 min before. So you should keep those in mind as well even in a small airport.
One very important point that is often overlooked is the baggage check-in cutoff time. While it is 30 minutes for most domestic flights on American Airlines, there are exceptions, which you can check-out here:
Other airlines will have different cutoff times, so make sure to check with your airline.
This almost bit me in the rear once in Las Vegas, which instead has a 45 minute cutoff time. I completed my self-checkin with around 7 seconds to spare, with the lady at the ticketing counter breathing down my neck (and pretty much counting down as I was going through the process =D).
International flights usually have a 60 minute cutoff time. Once again this figure will vary by airlines. Since you'll most likely be checking luggage when flying internationally, it makes sense to get there at least 90 minutes early, depending on the airport and the time of year. Some airports such as CDG in Paris have dreadful check-in times, so I can confirm first-hand AA's recommendation that you show up at least 3 hours in advance there (that's my second most frequent airport).
Other than baggage check-in cutoff time however, there is absolutely no reason to show up any earlier for international flights than for domestic flights. Everything else is exactly the same; be at the gate however late you feel comfortable with (without risking losing your seat, ie. up to ~30 minutes before boarding).
Another important point when flying red-eyes and such is the TSA security checkpoint closing times. These vary by airports, so check the TSA site or your airline's site. If I remember correctly, it is 11 PM at D/FW but I've seen as early as 10 PM (I believe it was at LAX). Of course, those times may have changed since, so always check for updated times before flying a red-eye.
I've been bumped to a later flight for arriving 2-3 minutes after their closing time (trust me, they're not at all flexible about this, and having to go home only to come back 4 hours later for a 5 AM flight is terrible).
I usually arrive between 1.75-2hrs before an international flight and I've never missed a flight. Although I wouldn't arrive any later than that (don't need to cause extra stress!). Different airlines can also close their check-in counters at different times so you don't want to be cutting it too close.