The "F.VIII" was Fokker's first twin-engined airliner, a reflection of the increasing power available from the light radials engines of the time. All their previous designs had an engine in the nose, and its absence in the "F.VIII" lead to less prop-wash wear and tear on the fuselage and much lower vibration levels for passengers. The first aircraft used 358 kW (480 hp) Bristol Jupiter radial engines built under licence by Gnome-Rhone, strut mounted and uncowled under the wings. KLM later re-engined theirs with 391 kW (525 hp) Pratt and Whitney Wasp T1D1 radials, cowled with Townend rings and mounted further forward than the Jupiters. One aircraft, which for part of its life flew as "PH-OTO" was used to explore the effects of mounting engines in, rather than below the wing. There were concerns that this arrangement, which became standard in later propeller driven aircraft would seriously disturb the airflow over the upper wing. It used 589 kW (790 hp) Wright Cyclones.