Veuling, the Spanish budget airline, forced two violinists in a string quartet to carry their instruments unprotected on board, or face a steep financial penalty. They were quite rude about it.
This now appears to be the airline’s policy. Violinist David Peralta booked an Iberia flight from Amsterdam to Barcelona and found his ticket assigned to Vueling. Iberia, apparently, is a part-owner of this shaky company.
Norman Lebrecht has more to say here on Slipped Disc