Grumman XF9F-2 Panther     

                              

                                  In  light of the usually prevalent thinking in the US regarding the use of NIH* goods and services,
                                  the fact that the first two prototype Grumman Panthers were powered by Rolls-Royce Nene engines
                                  is quite remarkable.   This untenable position was soon rectified with the third prototype, which had
                                  the Allison J33 installed.    However, it turned out that the Allison engine was so unreliable that the
                                  54 F9F-3s built with this power plant were soon converted to F9F-2s which had the Pratt & Whitney
                                  J42-P-6 (the licence-built Nene)!   The Panther was the US Navy's most extensively used fighter
                                  during the Korean War.  Most numerous variant was the F9F-5 with 616 built.

                                  *NIH - Not Invented Here -  There was, in the 1950s, (less now) a tremendous resistance on the
                                  part of US engineers (didn't matter whether it was planes, trains, buses, or boats) to regard with
                                  deep suspicion anything invented outside of the borders of the U.S.A., regardless of how efficient/
                                  effective the product was.