I've travelled lots with bikes, I've taken carbon, steel and titanium frames with no issues at all.
If you've ever seen baggage loaded onto planes, they're put onto pallets/cages (smaller for budget EU flights and quite big for transatlantic) which are usually about four cases deep. They try to pack as much into a pallet/cage as possible, and since most suitcases are regular shapes and your bike bag isn't, it'll go separately. It also certainly won't go at the bottom, as it'll have been checked in oversized baggage anyway and will be last to go on with the other sports equipment like golf bags etc.
They don't on Easyjet, at least not from Stansted or Luton. It all gets man-handled item-by-item on and off the plane. I've seen the process being done a few times, and on each occasion I've been glad I've been using an Alans Bike Box.
I've travelled lots with bikes, I've taken carbon, steel and titanium frames with no issues at all.
If you've ever seen baggage loaded onto planes, they're put onto pallets/cages (smaller for budget EU flights and quite big for transatlantic) which are usually about four cases deep. They try to pack as much into a pallet/cage as possible, and since most suitcases are regular shapes and your bike bag isn't, it'll go separately. It also certainly won't go at the bottom, as it'll have been checked in oversized baggage anyway and will be last to go on with the other sports equipment like golf bags etc.