The Fokker F-11 was a luxury flying boat produced as an ‘air yacht’ in the United States in the late 1920s.
Technically the aircraft was the Fokker Aircraft Corporation of America’s Model 9.
It was sold in North America as the Fokker F-11 and was offered in Europe as the Fokker B.IV.
In 1922 Fokker designed the B. I flying boat, one of which was delivered to the Dutch Navy.
The design was updated in 1926 as the Fokker B.III, which the Dutch Navy refused to purchase.
The B.III was rebuilt as a civilian passenger plane, the B.IIIc.
When that airplane failed to sell Anthony Fokker had it sent to his American subsidiary, Fokker Aircraft Corporation of America.
The intent was to use the B.IIIc as a pattern for an amphibious biplane to be manufactured in the USA.
The B.IIIc eventually did sell.
When Harold Vanderbilt’s custom-built Kirkham Air Yacht was destroyed in a hangar fire, he quickly needed a new air yacht, so he purchased the B.IIIc which was replaced by the prototype F-11 when it became available.
Fokker Aircraft Corporation of America decided to redesign the aircraft extensively and convert it to a monoplane configuration by mating a redesigned fuselage to the wings of the Fokker Universal.
That decision required Fokker Aircraft Corporation of America Chief Engineer Albert Gassner to create a new aircraft.
Both the fuselage and the wing were so extensively redesigned that they no longer bore much resemblance to their B.III and Fokker Universal origins.
The production F-11A had a high mounted Fokker F.14 wing.
The pusher engine nacelle with a 525-horsepower Pratt & Whitney Wasp was strut mounted atop the wing.
The prototype F-11, which first flew in 1928, was an amphibian with a retractable combination sponson/landing gear.
It was the only F-11 Amphibian so equipped.
The prototype was converted into a flying boat with wing-mounted floats like the F-11As.
The production machine was the F-11A which had the F-14s wooden wing and a 525 hp Wright R-1750D Cyclone engine.
Because Fokker Aircraft Corporation of America lacked the facilities to produce the duralumin fuselages, Fokker America arranged to have the hulls constructed in the Netherlands.
Initially, 20 were ordered but only 6 were completed and delivered to North America.
The Fokker F-11A was a single-engined monoplane flying boat with a duralumin hull and wooden wing.
F-11 or B.IV
Prototype with B.III hull, Universal wing and Pratt & Whitney Wasp engine, later replaced with Wright Cyclone.
F-11A or B.IVa
Production version with redesigned fuselage and wing and Wright Cyclone engine.
Modified with by the replacement of the single engine with a nacelle containing two engines in a push-pull arrangement.
F-11A modified with 275 h.p. Pratt & Whitney Hornet and seating increased to eight.