I recently asked Flybe to clarify the position with carrying Trunki's as cabin baggage - as they exceed with the maximum size limit. Flybe were kind enough to link me to a FAQ on their website. At the time of writing, the text said "Yes, Trunkis can be carried within the cabin as long as they meet your cabin baggage entitlement along with the weight and size restrictions." with a link to a section of the site which gave the max dimensions as being smaller than a Trunki. The flybe staff were quick to notice and agreed that if you could buy smaller Trunki's then they would be OK. Ideally the need to update the website to say "No, they are too big"