Haynes received the Distinguished Flying Cross and the Order of the Merit of Chile for his role in February 1939 as commander of the experimental aircraft, the Boeing XB-15, carrying of American Red Cross emergency supplies to Santiago, Chile, to help the survivors of the 1939 Chillán earthquake. Haynes and his ten-man crew won the Mackay Trophy for their part in the nearly round trip voyage. The flight showed the world not only the lengths to which the U.S. could go to mount a humanitarian relief mission but also the range and payload capability of the new bomber.