I recall the P&O S-76 tried to land on some mattresses on the QE2 a few years ago. Unintentially though.....
http://www.aaib.gov.uk/cms_resources...LC%2012-94.pdf
Seriously, though, it's worth bearing in mind that there is the potential to cause damage to the aircraft from unrestrained mattresses which may make a bad day get even worse! It's something I mention in our checklist drills for 'Undercarriage will not extend'