Do you mean as hand luggage, or in the hold?
Airlines seem to be getting tougher on hand luggage these days.
It's a few years ago now, but while travelling to/around India we obviously didn't take suitcases but large back-packs.
Because they aren't particularly secure we bought some strong canvas material & had kit-bags made (with metal eyelets/hoops around the top, so padlocks & cable ties could be used) which our backpacks went into & never had any problems at airports.
In fact we usually got our bags 1st @ baggage collection, because they tended to be unloaded last & put on top of the flatter suitcases by the handlers.
btw,He who dies with the most toys, WINS!Nikon D800E & D700 bodies + Nikon 200-400mm F4 VR1, 50mm F1.4G, 16-35mm f/4G VR, 105 F2.8 VR macro, 70-300mm lenses. A couple of filters, Giotto tripod & ballhead. Lowepro Slingshot 302 AW