United Air Lines  Douglas DC-6B  N37547          (c/n   43257)
                        
                              

                                This is not so much an image of a United DC-6B as a photograph of that spectacular hole in the ground,
                                the Grand Canyon.   As described in the entry for TWA's Super Constellation, this was the scene of a
                               devastating collision in 1956.  United's DC-6Bs (the best of the Douglas four motor transports, in my
                               opinion) first came on line in early 1951.  This was the first of 50 of them (including a few DC-6A freight-
                               ers) used by the airline.