So, what goes on behind the scenes of a preflight check? Well for starters, there are different checks depending on the mission of the flight. At most airlines they have a full preflight check, a walk around , & a post flight check. The preflight check is more thorough & is done once a day for the first flight in the morning. It includes a full security sweep of the airplane. It also checks for any obvious damage from overnight such as a tug hitting the aircraft. They check for any missing panels.The pilot will then check for any missing ,or loose rivets from the fuselage. They check for any hydraulic leaks, tire pressure,& traction. They check baggage loading, & fuel loading. They check for any snow contamination. The walk around inspection is very similar to the preflight except, it's more expedient. It's completed after every subsequent flight that day. Finally, after the last flight of the day, we do a post flight inspection. Again, this is similar to the other checks except we are looking for any write ups for maintenance. The goal is to catch any potential problems at the end of the day so the next morning flight won't take any delays. The preflight is an important component of the pilots job & is usually done within 10-15 minutes.