Delta Air Lines is trialling a system where passengers' hand luggage is preloaded above their allocated seats before boarding begins.
The Early Valet service sees airline employees take specifically-tagged carry-on bags at the departure gate and place them on-board.
It is currently being trialled on around two dozen flights out of Delta's busiest airports — Atlanta, New York, Los Angeles, Detroit, Minneapolis, Salt Lake City and Seattle.
The trial began on Monday and is expected to last until the end of August. The number of flights taking part will increase during June, while those selected will primarily be on leisure routes.
Delta spokesman Morgan Durrant said the airline first trialled the Early Valet service last summer in Atlanta and Los Angeles and noted a reduction in boarding time.
The idea is to test if Delta employees can load hand baggage quicker and in a more logical manner than passengers.
Earlier this week, Delta and its transatlantic partner Virgin Atlantic announced they will open a lounge bar at London's The O2 venue this summer (see news, June 2).