United Airlines has a dedicated team that transfers luggage from one plane to another that has tight connections. These are referred as "Hot Bags." They separate bags when loading so connection bags will always be off loaded before local bags. The next time you're on a flight, look out at the baggage belt. The person at the end will be loading connection bags that have time and local bags. A separate person on the side of the belt, will be pulling off "Hot Bags" for immediate delivery straight to the next gate. Baggage can be loaded even after the plane is being towed off the gate as long as the tug driver has contact with the pilot.

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