When do airline pilots arrive at airport?
Airline pilots generally arrive at the airport 2 hours before departure. 

Typically, a pilot will gather in a meeting with other pilots flying the same flight (who he/she may have never met before; but that is not a problem as there are Standard Operational Procedures which every pilot follow). They will discuss the flight plan (including expected delays, departure / arrival routes and procedures), weather, review the loading sheet &amp; fuel etc.

After the pilots' meeting, they will also meet the flight crew and have a brief discussion about the flight. Matters such as expected delays, transport of patient (sick passengers) needing medical attention etc. will also be brought out.

Around 30~45 minutes before departure, the pilots will board the plane. One pilot will program the Flight Management Computer in the cockpit while the other will conduct a walk-around.

There are "stand-by" pilots ready to takeover whoever is unable to report to duty at the airport. They can be anywhere and doing anything while on call, however they must be able to arrive at the airport typically 1~2 hours after receiving a call. Also, they must not consume alcohol while on call as this will invalidate their flying status.