Fournier RF-5

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RF-5
Fournier RF 5
Type: Touring motor sailer
Design country:

FranceFrance France - RF-5 Germany - RF-5B
GermanyGermany 
Manufacturer:

Sportavia
Helwan
Aerojaen

First flight:

Jan. 22, 1968 - RF-5
May 15, 1971 - RF-5B

Commissioning:

1969

Production time:

1968-1977

Number of pieces:

RF-5
1 Fournier, Nitray
134 Sportavia
10 Aerojaen

RF-5B
80 Sportavia
approx. 20 Helwan

S-5 / C-1
5 Sportavia

The RF-5 is a two-seat touring aircraft designed by French aircraft designer René Fournier.

history

The RF-5 was a design by the French designer René Fournier , who further developed the elegant design of the RF-3 and the RF-4 into a two-seater at the request of Alfons Pützer in 1966, which was to compete with the already successful SF 25 . The RF-5 prototype was created in early 1967 in René Fournier's design workshop in Nitray, France. The completed prototype was transported by truck from Nitray to the Dahlemer Binz in December 1967 , where Bernard Chauvreau with the WNR. 5001 took off for its first flight on January 22, 1968. In the subsequent flight tests, the Rectimo 1600 engine used had design deficits that led to a change to the Limbach L1700E . On May 28, 1969, the Luftfahrt-Bundesamt (Federal Aviation Office) issued the type approval for this configuration for the RF-5 as a motor glider with device identification sheet 695 . The approval as a powered aircraft in France with the single-igniter L1700E engine proved difficult and was later abandoned. In the years that followed, a number of further developments and derivatives were developed from the RF-5, which are described under "Further developments".

construction

RF-5 with retracted main wheel, Prague-Letnany 2009

The RF-5 is a wooden , two-seater, self-launching, self-supporting low- wing aircraft . The crew sits one behind the other, which helps reduce the frontal area and thus the air resistance. Originally, the rear seat of the prototype was located behind the cargo hold. During the construction phase, Fournier combined both seats and relocated the cargo hold to the rear of the cabin. A unique selling point is the aerobatic suitability, which only a few touring motor gliders have, as well as the relatively high cruising speed of up to 170 km / h (RF-5) at that time . The chassis consists of a retractable central wheel and a support wheel under each wing, similar to the SF 25 .

With the three-part wing, the outer parts were taken from the RF-4. The span can be reduced by the foldable outer wings, which then rest on the inner wing. The wingspan of the RF-5 is 8.74 m, and the RF-5B version is 11.22 m. The wing is constructed conventionally and has a box spar and a torsionally rigid plywood nose.

With the prototype WNr. In 5001, a Rectimo engine based on a 1600 cc VW engine was initially used. After cooling problems arose during testing with this engine specially developed for the RF-5, the company Limbach Flugmotoren from Königswinter provided the later 68 hp four-cylinder four-stroke engine SL1700E based on the 1700 m³ VW engine for the RF-5 available, which was used in the series machines. The L1700E was initially certified as part of the RF-5 type certification. Over time, most of the engines were replaced by Limbach 2000 or Sauer 2100, which deliver 10 to 20 hp more starting power.

The Idaflieg performance measurement showed the same value for the Sparrowhawk RF 5B with a glide ratio of 23.5 as for the ASK 16 and SF 28A . The basic version is indicated in various places with glide ratios from 18 to 22.

Marketing and further development

An overview of all RF-5 and RF-5B built by Sportavia-Pützer, Aerojaen and Helwan can be found at

Fournier RF-5 series production at Sportavia-Pützer (1969–1975)

René Fournier granted the exclusive license rights for the series production of the RF-5 in December 1967 to Sportavia-Pützer GmbH on the Dahlemer Binz, for which Fournier had developed the aircraft. Series production of the RF-5 started at Sportavia-Pützer at the end of 1968. A total of 43 RF-5s were built in the first year of production for the German, Finnish and Austrian markets. Unique pieces also went to South Africa in 1969. The first machines for the French sales partner Alpavia were delivered at the end of 1969. The unfavorable development of the exchange rate and the restrictions in the French approval of the RF-5 only led to a low demand for the RF-5 in France. Similar problems arose in England, where the sales partner Sportair received the first machines in March 1970. Here, too, only a few copies could be sold. Pützer refrained from selling the RF-5 in North America because the L1700E single-igniter engine was not approved there. Only in the used aircraft market did individual aircraft later make their way to the USA. Individual pieces were sold in Belgium, Spain and Switzerland, as well as to South America and Japan, while the majority of the RF-5 production remained in Germany. As early as 1971, production at Sportavia-Pützer was cut back to one aircraft per month. After 1972 only a few individual pieces were produced in response to specific customer requirements. The production of the RF-5 was stopped by Sportavia-Pützer in the mid-1970s after 135 units had been built.

Sportavia RF-5B Sparrowhawk (1972-1976)

Since the flight performance in the basic version with a glide ratio of 18 and a minimum sink rate of 1.4 m / s did not come close to the flight performance of comparable competitive models such as the SF 25 disc , Alfons Pützer left the RF-5 at Sportavia largely independent of René Fournier optimize their gliding characteristics. This resulted in the RF-5B "Sperber" in 1971, in which the wingspan was increased from 13.75 m to 17 m by extending the middle section of the wing. At the same time, Manfred Schliewa lowered the fuselage behind the cockpit to improve all-round visibility. In principle, a new aircraft based on the RF-5 was created, which took off for the first flight on the Dahlemer Binz on May 15, 1971 and was approved as an RF-5 series on May 10, 1972 by expanding the RF-5 device identification sheet 695 . Series production of the RF-5B started at Sportavia-Pützer in 1972 with two copies per month. Between 1973 and 1976, a copy was made every month on the Dahlemer Binz, before production was discontinued in 1977 after 80 copies had been built. In addition to Europe, the USA, Australia, South Africa and Turkey were among the sales markets for the RF-5B. A license production of the RF-5B took place at the Egyptian aircraft manufacturer Helwan near Cairo. The model achieved particular fame through aerobatics by Wilhelm "Salzmann" Düerkop in formation with Hannes Mattes on an RF-4D.

Helwan RF-5B license production in Egypt (1974–1975)

Egypt was interested in acquiring an RF-5B for pilot training in 1973. Four RF-5Bs were delivered to Egypt from Sportavia production until the beginning of 1974. The Egyptian aircraft construction company Helwan in Heliopolis acquired the license building rights for a further 20 RF- 5Bs in 1974. Here in 1974 about 20–30 more RF-5B (WNr. 10xx) were built, some with assemblies from Germany. The aircraft remained in service in Egypt until 1983 and were then partly sold back to Europe.

Further RF-5 variants (1972–1982)

Both René Fournier and Sportavia-Pützer worked on a number of enhancements to the RF-5 to improve its competitiveness. Since the L1700E as a single igniter engine did not meet the approval requirements in the USA, Alfons Pützer had an RF-5 equipped with a 60 hp Franklin 2A-120 two-cylinder four-stroke engine and an enlarged fuel tank under the name Sportavia RF-55 . After Franklin gave up further development of the engine, work on the RF-55 at Sportavia was also ended. As the Sportavia RF-5D , an RF-5B Sparrowhawk with a shortened wing and a 74 hp Sportavia Limbach SL1700ED engine was announced at the 1974 ILA, but it was never built like this. René Fournier also tried to revive the RF-5 concept again in 1982 at Fournier Aviation with the Fournier Aviation RF-5C . The RF-5C received a shorter wing, the more powerful Limbach L2000E engine and a fixed double landing gear. Neither a prototype nor series production was tackled at Fournier Aviation.

Sportavia test vehicle S-5 and C-1 (1971–1979)

Several RF-5s were used at Sportavia in the early 1970s to build test vehicles on behalf of the Federal Ministry of Defense . These test vehicles were primarily concerned with the locatability and detectability of aircraft.

In the case of the test vehicle S-5 , which became known as the “quiet flyer”, the noise emission should be minimized against acoustic detection on the ground and the detection of exhaust gases should be restricted by infrared-controlled missile systems. Manfred Schliewa equipped the S-5 with a 115 hp Lycoming engine with a soundproof cowling , a silencer and an exhaust gas cooling device. Hoffmann provided a noise-minimized three-blade propeller for the S-5. The first flight took place in May 1971. In addition to the S-5 prototype, another three S-5K should have been built by Sportavia by the mid-1970s.

The test vehicle C-1 was developed by Helmut Schrecker at Sportavia as a test vehicle for radar tests. For this purpose, the rear RF-5 cabin part was removed and replaced by a room for the measuring device. The C-1 received a wing with an increased span, similar to the RF-5B Sparrowhawk. Like the S-5, the C-1 was also equipped with a Lycoming engine and exhaust gas cooling system. In the wing box of the aircraft there was a mounting device with which the aircraft could be mounted on a support mast for ground tests. The first flight of the C-1 took place in November 1975.

The Sportavia test vehicles were dismantled at the end of the 1970s. The fuselage of the C-1 is now in the Aviation Museum in Wernigerode .

Aerojaen RF-5-AJ1 "Serrania" (1986–1995)

With the support of René Fournier, the Aeronautica de Jaen aircraft factory was established in Beas de Segura, Spain, in the mid-1980s , to which René Fournier granted the license rights to build RF-5 aircraft with an 80 hp Limbach L2000E engine. Aerojaen acquired the RF-5 equipment still stored at Sportavia and in 1991 began production of the Spanish RF-5, known as RF-5-AJ1 "Serrania". The first flight of a "Serrania" took place on February 23, 1991 in Beas under the leadership of Bernard Chauvreau . The type approval 73/1 by the Spanish aviation authority was granted in July 1992. In total, only 10 aircraft including the prototype in Beas were built between 1992 and 1995.

With the end of Spanish production, the development history of the RF-5 ended in 1995. Rene Fournier implemented the use of the two-seat RF-5 as a training aircraft from the beginning of the 1970s in the form of the all-metal Fournier RF-8 and from 1973 with the Fournier RF-6, which was geared towards the needs of flight schools .

The Friendship F3A and Friendship F4 by Erik Sandstroem are two-seater ultralight developments. However, they are based on the single-seat Fournier developments RF-3 and RF-4 and are therefore not to be regarded as further developments of the RF-5.

Technical specifications

RF-5, Castiglione 2012
Parameter RF-5 RF-5B
Crew / passengers 1 + 1 1 + 1
length 7.80 m 7.71 m
span 13.74 m 17.00 m
Wing area 15.16 m² 19.00 m²
Wing extension 12.5 15.3
Wing loading Max. 42.88 kg / m 2 Max. 36.80 kg / m²
Wing profile NACA 23015/23012 NACA 23015/23012
Glide ratio 18.1 at 104 km / h 23.5 at 98 km / h
Slightest sinking 1.51 m / s at 94 km / h and

Max. Wing loading

0.95 m / s at 80 km / h
Empty mass 450 kg 500 kg
Max. Takeoff mass 650 kg 700 kg
Cruising speed 165 km / h 150 km / h
Top speed 250 km / h 225 km / h
Max. Rate of climb 3.0 m / s 3.0 m / s
Max. Range 760 km 420 km
Engine 1 × Limbach L1700E
power 50  kW (68  hp )

See also

literature

Web links

Commons : Fournier RF-5  - collection of images, videos and audio files

Individual evidence

  1. ^ Rene Fournier: Mon reve et mes combats , Edition Sier, Jan. 2005, ISBN 978-2-9519-4580-7
  2. ↑ Test: Motorglider Fournier RF-5 , in Flug Revue June 1969, p. 108
  3. ^ Paul Zöller: Fournier Airplanes , 2017, ISBN 978-3-7460-4864-2
  4. ↑ John Taylor: Sportavia RF-5 . Ed .: Jane's All the World's Aircraft Publishing Ltd. tape 1969-70 , 1969, pp. 31 .
  5. ↑ John Taylor: Sportavia RF-5 . Ed .: Jane's All the World's Aircraft Publishing Ltd. tape 1972-73 , 1972, pp. 31 .
  6. ↑ Dipl.-Ing. Hans Zacher: Flight measurements on motor gliders. DFVLR Munich, 1970, accessed on March 18, 2020 .