See other failures under 000.html.
Erickson tandem fails at right rear dropout. From http://tandemgeek.wordpress.com/2011/04/02/oh-snap-rear-drop-out-breaks-out as of 2011/04.
Frame built roughly 2001, failed during hilly cycling tour. Team weight, usage, and other details unknown.
The break was welded and lasted for about another 9 months, then re-broke. The failed repair is shown above.
See also http://tandemgeek.wordpress.com/2011/04/11/oh-snap-update-1 and http://tandemgeek.wordpress.com/2011/04/18/oh-snap-update-2.
See also FAIL-151.html.