The Loening R-4 was a racer aircraft built by Loening in the early 1920s.

The R-4 featured a low-wing monoplane layout, and the Packard engine weighed three times the size of the aircraft and took up a quarter length of the R-4, nicknamed the "flying engine".

Both R-4 racers (AS68559 and AS68560) were entered in the 1922 Pulitzer Trophy race with poor results, being reported as "almost total flops".

Data from ,[1] Airwar : Loening R-4[2]General characteristics Performance