Large musical instruments as carry-on baggage.
Each covered carrier shall permit a passenger to carry a musical instrument that is too large to meet the requirements of § 251.3 in the aircraft cabin, without charging the passenger a fee in addition to the cost of an additional ticket described in paragraph (e) of this section, if:
(a) The instrument is contained in a case or covered so as to avoid injury to other passengers;
(b) The weight of the instrument, including the case or covering, does not exceed 165 pounds or the applicable weight restrictions for the aircraft;
(c) The instrument can be stowed in accordance with the requirements for carriage of carry-on baggage or cargo established by the FAA;
(d) Neither the instrument nor the case contains any object not otherwise permitted to be carried in an aircraft cabin because of a law or regulation of the United States; and
(e) The passenger wishing to carry the instrument in the aircraft cabin has purchased an additional seat to accommodate the instrument.