crashed
... that in 1955, a United Airlines Douglas DC-6 crashed only days after a device that could have prevented it was installed on a sister aircraft?
... that in 1955, a <a href="./United_Airlines" id="mwAns" rel="mw:WikiLink" title="United Airlines">United Airlines</a> <a href="./Douglas_DC-6" id="mwAnw" rel="mw:WikiLink" title="Douglas DC-6">Douglas DC-6</a> <i id="mwAn0">(similar example pictured)</i> <b id="mwAn4"><a class="mw-redirect" href="./MacArthur_Airport_disaster" id="mwAn8" rel="mw:WikiLink" title="MacArthur Airport disaster">crashed</a></b> only days after a device that could have prevented it was installed on a sister aircraft?