I really don't think Ryanair would go bust and it would be a disaster for the industry and local economies at many airports if they did. As for problems over off-loading their older fleet, don't forget they are starting the process of seeking offers from Boeing and Airbus for future fleet replacements. I'm 100% sure that the winning manufacturer acquiring the existing older fleet would form part of any such deal. Ryanair may be crass but they are not stupid...