Section 251.5 - Large musical instruments as checked baggageEach covered carrier shall transport as baggage a musical instrument that is the property of a passenger traveling in air transportation that may not be carried in the aircraft cabin if
(a) The sum of the length, width, and height measured in inches of the outside linear dimensions of the instrument (including the case) does not exceed 150 inches or the applicable size restrictions for the aircraft;(b) The weight of the instrument does not exceed 165 pounds or the applicable weight restrictions for the aircraft; and(c) The instrument can be stowed in accordance with the requirements for carriage of carry-on baggage or cargo established by the FAA.