Prints and Photos
Army Pilots w/ Tri Motored Fokker Plane 1249
" By the end of the 1930s trimotored airliners, like the Fokkers, Fords, and Boeings, had become standard equipment in America and elsewhere during the late 1920s. They could not easily be redesigned to mount retractable gear, but the trio of big, blunt radial engines that powered them could be shrouded with the new NACA cowling to give them much improved performance. Engineers at Langley took a Fokker trimotor powered by three Wright J-5 Whirlwind engines and fitted it with cowlings. Confident expectations of sudden enhancement of performance were dashed and engineers were baffled. They began to wonder if the installation of engines hadsomething to do with it. So as not to encumber the wing, the original designers had placed the engines on struts beneath thewing (or, in the case of biplanes like the Boeing 80, between the wings). After getting the big Fokker set up in the propellerresearch tunnel, Langley engineers ran a series of tests that conclusively changed the looks of multiengine transports to come.They discovered that the best position for the engines was neither above or below the wing, but mounted as part of itsstructure--situated ahead of the wing, with the engine nacelle faired into the wing's leading edge."