Outsize items
All items of luggage larger than the permitted cabin baggage size (maximum length 56 cm, width of 45 cm and depth of 25 cm, including wheels, handles and external pockets) must be checked in to be placed in the aircraft hold. The only exception is musical instruments. These are allowed as a second item of cabin baggage if they do not fit into the cabin bag. They will however need to be screened and passengers should check with their airlines as to whether there are special arrangements (e.g. purchasing an extra seat) for these large instruments.
David