An <a href="https://en.wikipedia.org/wiki/Iberia_(airline)" id="mw4A" rel="mw:WikiLink" title="Iberia (airline)">Iberia Airlines</a> <a href="https://en.wikipedia.org/wiki/Boeing_727" id="mw4Q" rel="mw:WikiLink" title="Boeing 727">Boeing 727</a> <a href="https://en.wikipedia.org/wiki/Madrid_runway_disaster" id="mw4g" rel="mw:WikiLink" title="Madrid runway disaster">collides</a> with an <a href="https://en.wikipedia.org/wiki/Aviaco" id="mw4w" rel="mw:WikiLink" title="Aviaco">Aviaco</a> <a href="https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-9" id="mw5A" rel="mw:WikiLink" title="McDonnell Douglas DC-9">DC-9</a> in dense fog while the two airliners are taxiing down the runway at <a href="https://en.wikipedia.org/wiki/Madrid–Barajas_Airport" id="mw5Q" rel="mw:WikiLink" title="Madrid–Barajas Airport">Madrid–Barajas Airport</a>, killing 93 people.