We flew Easyjet to Ireland for the Loughstock Gathering the other weekend. I was not once asked what my hand luggage was but I was asked if I had anything to put in the hold to which I replied "no". My fiddle is in a large rectangular case and fitted in the overhead lockers easily. MudGuard kept making comments about my 6 pieces of hand luggage which I think was really 3 but hey! My advice to you is to always take your instruments in the cabin. Most airlines have a policy that says that instruments are classed as additional hand luggage if they fit in the over head lockers. I would never put an instrument in the hold unless it had a very strong case!