Fokker F.III

Design and development

The Fokker F.III was a straightforward development of the F.II. A widened cabin allowed all five passengers to sit within; in the earlier aircraft, one passenger sat alongside the pilot in his exposed cockpit. The pilot now sat alongside the engine, which was offset laterally by about 100 mm; whether to port or starboard depended on the type of engine installed. Although this unusual arrangement meant that pilots were "burned on one side and frozen on the other," they had a much better view than from the F.II. The view was further improved by a cut-out in the wing leading edge for the pilot's head, allowing his seat to be raised. The external wing struts of the F.II were removed, leaving a clean cantilever wing. The trapezoidal windows seen in the Grulich built F.IIs were standard on the F.III.

Like its predecessor, the F.III was initially powered by a readily available, war surplus 138 kW (185 hp) BMW IIIa engine, but once again KLM re-engined theirs with the 172 kW (230 hp) Armstrong Siddeley Puma.

A seaplane version was developed by Fokker, called the F.IIIw. However, this design did not go into production. The design had twin floats, and it had a longer fuselage and rudder. Such was the pace of aircraft development no blueprints are known, only several photographs.

An improved model known as the F.IIIs was also made, and this had new fuselage and tail fin. It was also called the Grulich V.I.

Operational history

The F.III was first used by KLM when they reopened their Amsterdam-London service on 14 April 1921 (they did not, at this time operate over winter). Soon, F.IIIs were also flying on routes to Bremen, Brussels, Hamburg, and Paris. They proved to be very reliable aircraft. KLM received 14 F.IIIs from Fokker's German factory at Schwerin during 1921 and built two more itself from spares in the following year. This final pair used 268 kW Rolls-Royce Eagle VIII engines, with the pilot on the left.

Another operator of new F.IIIs was Deutsch-Russiche Luftverkehrs Gesellschaft (Deruluft) which used nine aircraft on their Berlin-Königsberg-Moscow route from May 1922. These machines, partially built in Schwerin and finished in the Netherlands at Veere, had Eagle engines. One was a Fokker-Grulich.

Deutsche Aero Lloyd gained a licence to build F.IIIs as they had for F.IIs and the company, with its southern subsidiary built and operated 18 of these Fokker-Grulich F.IIIs. Most of these used BMW engines, typically the 186 kW BMW IV in preference to the 138 kW BMW IIIa. Some of these were re-engined with the 239 kW BMW Va, and were designated F.IIIc.

Another operator from new was the Hungarian airline Malert, which received six Dutch-built aircraft for their Budapest-Vienna-Belgrade service from 1922 to 1929. These initially had BMW IIIa engines, but later ran with 172 kW Breitfeld & Daněk Hiero IV engines. They had larger wings, increased in area by about 14%. Deutsche Luft-Reederei also operated two, originally intended for KLM. Four F.IIIs probably went to the United States.

Later F.IIIs changed ownership frequently as airlines went bankrupt or merged. They were still flying commercially in Germany until about 1936.

Accidents and incidents

The F.III as involved into two air crashes, that due to developing nature of air travel had a big impact. For example, one disappearance lead to the radios being required on aircraft.

• 1924 KLM Fokker F.III disappearance (This was the first major air accident of the airline KLM)
  • On 24 April 1924, Fokker F.III H-NABS of KLM departed Lympne for Rotterdam and Amsterdam. The aircraft was not heard of again. It was presumed to have crashed into the sea, killing the pilot and both passengers.
• On 25 June 1925, a KLM Fokker F.III, registration H-NABM, crashed at Landrécies, France in poor weather while on an Amsterdam-Paris service, killing all four on board.
• 1928 KLM Fokker F.III Waalhaven crash

Operators

;Australia

• 1 Privately owned ;Danzig Free City of Danzig
• Deutsche Luft-Reederei ;
• Det Danske Luftfartselskab ;Weimar Republic
• Deutsch-Russiche Luftverkehrs Gesellschaft (Deruluft)
• Deutsche Aero Lloyd
• Deutsche Aero Luft
• Sud-deutsche Luft Hansa ;Hungary
• Malert ;
• Koninklijke Luchtvaart Maatschappij (KLM) ;Soviet Union
• Deruluft ;Switzerland
• Balair, operated 5 ex-KLM 1926-1928
• Ost Schweizer Aero Gesellschaft (East Swiss Aero Company); operated 1 ex-Balair until 1929

Specifications

|prime units?=met General characteristics

|max takeoff weight kg= Powerplant

Performance

|never exceed speed kmh= |minimum control speed kmh= |wing loading kg/m2= |fuel consumption kg/km= |power/mass=

References

References

1. "Fokker F.III".
2. (26 April 1923). "Lost Aeroplane. Unavailing Search For Dutch Machine".
3. (1994). "FOKKER COMMERCIAL AIRCRAFT from the F.1 of 1918 up to the Fokker 100 of today.". N. V. Konninklijke Nederlandse V. Fokker.
4. (1924). "Jane's all the World's Aircraft 1924". Sampson Low, Marston & company, ltd.
5. (26 May 1921). "The Fokker F III Commercial Monoplane".
6. "The Incomplete Guide to Airfoil Usage".