I would like to defer to George, but does't the FAA makes the rules, not each individual airline. Three hours is ridiculous, DIA is our home airport with more people in a day fly then STT in a month and 1 1/2 hours is always sufficient.
You are arguing the wrong battle. If you can make it to the other side of security, bags all checked in, printed boarding pass in hand you are golden unless you miss the call for your seat it is given away because you did not get through the door and sit in it.
The 3 hour or whatever it is in any given airport is the cut off set sometimes by the day and security level to get a boarding pass or hand the actual bag over. There are many times in many airports where the time you step out of the taxi is many minutes before you make it to the front of the line to get a boarding pass or hand in a bag. When the computer is set at 90 minutes, and 89 minutes you will be refused. It happens all over the world everyday. When the security level is changed and extra screening ordered a 30 minute airport can become an 60 minute airport in an instant.
Here is one sample of the computer cut off time for airports:
Without checked baggage:
The minimum check-in time requirement for customers without checked baggage is 30 minutes prior to departure, except for San Juan, where the requirement is 45 minutes, and Guam, where the requirement is 60 minutes.
With checked baggage:
For all airports within the U.S. and Puerto Rico, the minimum check-in time requirement for customers with checked baggage is 30 minutes prior to departure, with the exceptions noted in the chart below.
Please note that check-in and baggage check must be completed by the specified number of minutes before scheduled departure, but we recommend allowing additional time.
Check-in and boarding requirements for flights within the U.S., Guam, Puerto Rico and U.S. Virgin Islands
Departure Airport Baggage check-in completed
(number of minutes before departure)
Anchorage, AK (ANC) 45 minutes
Atlanta, GA (ATL) 45 minutes
Austin, TX (AUS) 45 minutes
Baltimore, MD (BWI) 45 minutes
Chicago, IL (ORD) 45 minutes
Cincinnati, OH (CVG) 45 minutes
Cleveland, OH (CLE) 45 minutes
Dallas/Fort Worth, TX (DFW) 45 minutes
Dallas, TX – Love Field (DAL) 45 minutes
Denver, CO (DEN) 45 minutes
Fort Lauderdale, FL (FLL) 45 minutes
Greenville-Spartanburg, SC (GSP) 45 minutes
Guam (GUM) 60 minutes
Honolulu, HI (HNL) 45 minutes
Houston, TX (IAH) 45 minutes
Indianapolis, IN (IND) 45 minutes
Jacksonville, FL (JAX) 45 minutes
Kona, HI (KOA) 45 minutes
Las Vegas, NV (LAS) 45 minutes
Los Angeles, CA (LAX) 45 minutes
Maui, HI (OGG) 45 minutes
Miami, FL (MIA) 45 minutes
New York, NY/Newark, NJ (EWR) 45 minutes
Orange County, CA (SNA) 45 minutes
Orlando, FL (MCO) 45 minutes
Philadelphia, PA (PHL) 45 minutes
Phoenix, AZ (PHX) 45 minutes
Pittsburgh, PA (PIT) 45 minutes
Reno, NV (RNO) 45 minutes
San Diego, CA (SAN) 45 minutes
San Francisco, CA (SFO) 45 minutes
San Juan, Puerto Rico (SJU) 60 minutes
Seattle, WA (SEA) 45 minutes
St. Louis, MO (STL) 45 minutes
St. Thomas, U.S. Virgin Islands (STT) 60 minutes
Tampa/St. Petersburg, FL (TPA) 45 minutes
Washington, D.C. – Dulles (IAD) 45 minutes
Washington, D.C. – National (DCA) 45 minutes
All other airports within the U.S., Puerto Rico and the U.S. Virgin Islands 30 minutes
Boarding ends 15 minutes before the scheduled departure time for flights within the U.S., Puerto Rico and the U.S. Virgin Islands. Boarding ends 30 minutes before the scheduled departure time for flights out of Guam.
Let me try again...
When you start the day the first item is you checked in with a boarding pass. Every airline computer has a cut off number of minutes for that. The second order of the day your bag fully checked in. Every airline computer has a cut off for that to be FULLY completed.
The third order of the day get yourself through security and in your assigned seat before the airline does their seat count and either gives up your seat or closes the door without you.
STT has many infrequent travelers, hungover, and even drunk travelers. Families will all sorts of junk and overloaded carry on. Everything takes longer there than most business frequent traveler airports. A big checkout departure day will lead to lines and time lost getting to the front of the line where you actually can conduct your business with the computer counting down to the unforgivable cut off second for that flight that day.
Today the computer was set at 90 minutes to stop taking bag at the AA counter in St. Thomas (STT). Tomorrow it could be more, it could be less. One thing is certain. You will not find the person who has the password to change those times.