Northwest Airways  Sikorsky S-38B   NC303N   (c/n 414-1)

                                  

                                        In 1931 the airline opened a branch line from Minneapolis to Duluth.  Since Duluth had no airport
                                        a couple of Sikorsky S-38s were used.  I believe the other one was NC304N.   In the meantime
                                        the third amendment to the Air Mail Act of 1925 (the so called Kelly Act) had been approved in
                                        1930 and was referred to as the Watres Act.  One of the provisos of this Act was to prohibit
                                        carriers from making route extensions which were longer than the original routes themselves.  For
                                        this reason, the operation of several smaller runs (such as the route to Duluth) benefited the airline
                                        in the long run, since the sum total of mileage of these allowed (in Northwest's case) easier expansion
                                        north and west.    When, for instance, the airline wanted to fly into Winnipeg in 1931, they were at
                                        first limited to fly only to the Canadian frontier at Pembina.  It wasn't until 1933 that the extension
                                        to Winnipeg was legally possible.