Fokker F.VII


The Fokker F.VII, also known as the Fokker Trimotor, was an airliner produced in the 1920s by the Dutch aircraft manufacturer Fokker, Fokker's American subsidiary Atlantic Aircraft Corporation, and several other companies under license. It was an airliner that could carry 6-12 people, depending on the version, and it used a variety of engines and engine configurations; while the first versions had a single nose engine, most were produced with three engines.
The F.VII was an important airliner in the 1920s and 1930s; made in several versions, it was used for record breaking flights. An enlarged variant of the F.VII, the F-10, was involved in a famous aviation accident in 1931, leading to safety reforms in the USA. It was also used for an attempt to reach the North Pole, although there was a debate if it did reach all the way there: the aircraft was at least flown in arctic conditions in this attempt. Less controversially, it was flown in the first flight across the Pacific from Australia to the United States, and earlier it was used in flight from the United States to Hawaii.
In the 1930s, the aircraft began to fall out of favor as newer designs that were larger, faster, and more streamlined entered service. Some major variations on this design included the Fokker F-10, which was bigger and could carry four additional passengers, and the Fokker F.VIII, which omitted the central engine thus becoming a twin-engined aircraft. The Fokker F.VII was also produced by licensees outside the Netherlands including SABCA, Avia, Avro, and others.

Design and development

The F.VII was designed as a single-engined transport aircraft by Walter Rethel. Five examples of this model were built for the Dutch airline KLM. One of these aircraft, registered H-NACC, was used in 1924 for the first flight from the Netherlands to the Dutch East Indies. In 1925, while living in the US, Anthony Fokker heard of the inaugural Ford Reliability Tour, which was proposed as a competition for transport aircraft. Fokker had the company's head designer, Reinhold Platz, convert a single-engine F.VIIA airliner to a trimotor configuration, powered by Wright Whirlwind radial engines. The resulting aircraft was designated the Fokker F.VIIA-3m. Following shipment to the US, it won the Ford Reliability Tour in late 1925. The Trimotor's structure consisted of a fabric-covered steel-tube fuselage and a plywood-skinned wooden wing.
The Fokker F.VIIB-3m had a slightly increased wing area over the F.VIIA-3m, with power increased to per engine, while the F.10 was slightly enlarged, carrying 12 passengers in an enclosed cabin. The aircraft became popularly known as the Fokker Trimotor.
The Fokker F.VIII was similar, but a twin engine configuration rather than a trimotor, and it was bigger. The Fokker F.IX had a similar configuration to the F.VII, but it was quite a bit larger and carried 20 passengers.

Operational history

The eight- to 12-passenger Fokker was the aircraft of choice for many early airlines, both in Europe and the Americas, and it dominated the American market in the late 1920s. However, the popularity of the Fokker quickly waned after the 1931 crash of a Transcontinental & Western Air Fokker F.10, which resulted in the death of Notre Dame football coach Knute Rockne. The investigation revealed problems with the Fokker's plywood-laminate construction, resulting in a temporary ban from commercial flights, more stringent maintenance requirements, and a shift to all-metal aircraft such as the similar Ford Trimotor and later Boeing 247 and Douglas DC-2.

Pioneers and explorers

The F.VII was used by many explorers and aviation pioneers, including:
;F.VII: Single-engined transport aircraft, powered by Rolls-Royce Eagle or Napier Lion 12-cylinder inline engines, accommodation for two crew and six passengers; five built. One converted to use Bristol Jupiter 9-cylinder radial and two to use Gnome-Rhône built Jupiter VI engine.
;F.VIIA : Single-engined transport aircraft; the capacity was increased to carry 8 passengers and the aircraft received a new, simplified undercarriage with suspension and aerodynamic improvements. Flown on 12 March 1925. First aircraft had a V-12 Packard Liberty engine, but a further 39 F.VIIA examples had mostly Bristol Jupiter or Pratt & Whitney Wasp radial engines.
;F.VIIA-3m: The result of an attempt to improve the reliability of the aircraft by installing two additional underwing engines; flown on 4 September 1925. The first two aircraft were otherwise identical to the F.VIIA. From the third aircraft, the fuselage was 31 in longer and was powered by 200 hp Wright J-4 Whirlwind radial engines. Probably only 18 were built, while many F.VIIA were upgraded to the F.VIIA-3m standard.
;F.VIIB-3m: Main production variant with heavier engines as well as a greater wing span and modified wing geometry; 154 built, including those built under licence.
;F-9: American-built version of the Fokker F.VIIB-3m; built by the Atlantic Aircraft Corporation in the United States.
;F-10: Enlarged version of the Fokker F.VII airliner, able to carry up to 12 passengers; built by the Atlantic Aircraft Corporation in the United States.
;C-2: Military transport version of the Fokker F.9, powered by three 220 hp Wright J-5 radial piston engines, accommodation for two pilots and ten passengers; three built in 1926 for the US Army Air Corps.
;C-2A: Military transport version for the US Army Air Corps, with greater wingspan, powered by three 220 hp Wright J-5 radial piston engines, accommodation for two pilots and ten passengers; eight built in 1928.
;XC-7: One C-2A fitted with three 330 hp Wright J-6-9 radial piston engines. Re-designated C-7 when four C-2A examples were similarly reconfigured.
;C-7: Military transport conversion of C-2A for the US Army Air Corps by re-engining with 300 hp Wright R-975 engines. XC-7 prototype and four C-2As re-designated in 1931.
;C-7A: Six new production C-7 aircraft with larger wings, new vertical fin design, and fuselages patterned after the commercial F.10A.
;XLB-2: Experimental light bomber version of the C-7, powered by three 410 hp Pratt & Whitney R-1380 Wasp radial piston engines; one built.
;TA-1: Military transport version for the US Navy and Marine Corps; three built.
;TA-2: Military transport version for the US Navy; three built.
;TA-3: Military transport version for the US Navy, powered by three Wright J-6 radial piston engines; one built.
;RA-1: Re-designation of the TA-1.
;RA-2: Re-designation of the TA-2.
;RA-3: Re-designation of the TA-3.

Licensed versions

  • SABCA, 29 aircraft built.
  • Avia, 18 aircraft built.
  • Three aircraft built in Italy as the IMAM Ro.10, powered by three 215 hp Alfa Romeo Lynx engines. Three built for operation by Avio Linee Italiane and Ala Littoria.
  • Plage i Laśkiewicz. Between 1929 and 1930, produced 11 examples of F.VIIB-3m, plus 20 of its own F.VIIB-3m bomber version.
  • Three aircraft built in Spain.
  • Avro, 14 aircraft known as Avro 618 Ten used Armstrong Siddeley Lynx engines

    Operators

Civilian operators

  • SABENA operated 28 aircraft.
  • Det Danske Luftfartselskab operated three F.VIIA aircraft.
  • CIDNA operated seven F.VIIA aircraft.
  • Air Orient operated eight F.VIIB aircraft.
  • STAR operated one F.VIIA aircraft.
  • Avio Linee Italiane
  • Ala Littoria
  • Malert operated two F.VIIA aircraft.
  • 2 F.VIIB-3ms operated by the Manchuria Aviation Company
  • KLM received all five F.VII aircraft and 15 F.VIIA.
  • Aero operated six F.VIIA aircraft for a short period in 1928. Since 1 January 1929, all aircraft were handed over to PLL LOT airline.
  • Polskie Linie Lotnicze LOT operated six F.VIIA and 13 locally license-built F.VIIB-3m between 1929 and 1939.
  • Aero Portuguesa operated one F.VIIB-3m aircraft.
  • CFRNA
  • CLASSA
  • LAPE
  • Ad Astra Aero at least one F.VIIB-3m
  • Swissair operated one F.VIIA and eight F.VIIB-3m aircraft.
  • American Airways, which later became American Airlines.
  • TWA
  • Pan Am operated F.VIIB-3m aircraft.