Mohawk Airlines Flight 40
...that in 1967 Mohawk Airlines Flight 40 crashed after a fire was sparked by a non-return valve being installed backwards?
...that in 1967 <b id="mwBdY"><a href="./Mohawk_Airlines_Flight_40" id="mwBdc" rel="mw:WikiLink" title="Mohawk Airlines Flight 40">Mohawk Airlines Flight 40</a></b> crashed after a fire was sparked by a <a href="./Check_valve" id="mwBdg" rel="mw:WikiLink" title="Check valve">non-return valve</a> being installed backwards?