also, the 247 was the first airliner with two engines which could fly on just one engine. the boeing 247 had special propellers. it could fly at 11,500 ft at full weight. the douglas dc-1 and some other airliners before world war ii used parts of the boeing 247's design. the 247 was supposed to carry 14 passengers and have pratt &amp; whitney r-1690 hornet engines, but the plane was made smaller and got different engines.