I haven't taken my bike on a flight since 2007! Back then, on a flight from LHR to STR (Stuttgart) on BA I rode to the airport, took the pedals off, deflated the tyres slightly (I don't believe there's any scientific reason for this!) and turned the handlebars. No wrapping, no box. The oversize luggage people simply wheeled the bike where they needed to, and seemed happy to do so. I believe not wrapping/boxing a bike isn't allowed any more. Pity, as I'm sure it's easier for everyone if a bike looks and acts like a bike.

Thinking about it, deflating the tyres and turning the handlebars does help stop the baggage handlers riding it around their warehouses