Fokker F.VII. 1928 - HistoryCategory: Airplanes Last change: June 2020
00128b Section 1928
Plage i Laśkiewicz Fokker F.VII/3m
The Fokker F.VII is a plane designed in 1924 at the Dutch Fokker aircraft plant. The aircraft has been used in air transport around the world for over 20 years. The aircraft was used as transport (civil and military), landing and bomber. The aircraft was built in several countries, including Poland in Lublin. The most popular version was the three-engine Fokker F.VIIb / 3m.
The Fokker F.VII aircraft was designed under the direction of Walter Rethel. It is a mixed-engine single-engine high-wing aircraft, taking a crew of two and 8 passengers. The first specimen was flown on April 11, 1924. However, only 5 copies of F.VII aircraft were built, because the enlarged and better model F.VIIa was developed, which was flown on March 12, 1925.
The aircraft had very good flight characteristics and was easy to fly. He was distinguished by good performance, especially range. The prototype had one Packard Liberty in-line engine, 420 hp. Serial aircraft were equipped with various engines, depending on the recipient's requirements. Some had Bristol Jupiter or Pratt Whitney Wasp star engines with 400-500 hp.
Due to the unreliability of the engines of the time, a three-engine system was proposed. Two additional engines were placed under the wings and profiled with fairings. The three-engine system increased flight safety. It was then a modern system, not used so far in passenger aircraft and the first system that gave the opportunity to continue flight after a single engine failure. The aircraft was designated F.VIIa / 3m. "3m" means three engines. He made his first flight on September 4, 1925. The drive was made up of successful Wright J4 Whirlwind star engines with 200 hp (147 kW) each.
During production, from the fifth copy, the hull was extended by 0.80 m to 14.60 m and in this way the cargo space was enlarged. Now the plane could take 10 passengers.
In 1927, an improved version of the aircraft was built at Fokker, which was designated Fokker F.VIIb / 3m. 220 HP Wright J5 engines were used. The aircraft also had several other changes. The wingspan was increased by 2.40 m. Better avionics was used.
Fokker F.VII in Poland.
Six Fokker F.VIIa aircraft were purchased in 1928 by Polish private airlines Aero, after which they were taken over by LOT Polish Airlines established on 1 January 1929. Initially, they had registration marks: P-POZM, P-POZN, P-POZO, P-POZP, P-POZR, P-POZS, and in PLL LOT: SP-AAM, SP-AAN, SP-AAO, SP-AAP, SP-AAR, SP-AAS.
Planes were used on domestic and foreign lines, for example to Chernivtsi and Vienna. Fokker F.VIIa had in-line engines in the W, Lorraine-Dietrich LD-12Eb system, with 464 HP (341 kW), built at the Polish Skoda plants.
In LOT Polish Airlines they were used until May 1936. In 1935, engines were replaced with Bristol Jupiter VIIF star engines, with a power of 529 hp (382 kW). Two of them were then sold to military aviation as school and landing aircraft.
Fokker F.VII/3m in Poland.
The first country that purchased a license for the Fokker F.VIIb / 3m aircraft, at the beginning of 1928, was Poland. Production was commissioned to Plage and Laśkiewicz in Lublin. In 1929-1930, 11 passenger planes and 20 planes were built in Lublin in the factory developed at the design office under the leadership of Ing. Jerzy Rudlicki's bomb version.
10 Fokker F.VIIb / 3m passenger aircraft and 3 copies were later rebuilt from bombers; were used by PLL LOT (with the marks: SP-ABA, SP-ABB, SP-ABC, SP-ABD, SP-ABE, SP-ABF, SP-ABG, SP-ABH, SP-ABI, SP-ABK and SP -AMI, SP-AMH and SP-AMK). PLL LOT aircraft were equipped in the years 1934-1935 with new Pratt & Whitney Wasp Junior TB engines with 420 hp (309 kW), with two-blade metal propellers, with adjustable pitch on the ground, allowing for slightly better performance.
In September 1, 1939, LOT Polish Airlines still had 4 aircraft. One plane was destroyed after the outbreak of war in a workshop at Okęcie. Others were evacuated to Romania.
In 1929, Zakłady Plage & Laśkiewicz offered the production of a variety of torpedo seaplane, on a float chassis, armed with an 800 kg air torpedo, suspended under the fuselage on the ejector of the construction engineer. W. Świątecki. The Navy did not order this version.
Written by Karol Placha Hetman