Fournier RF-4

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Fournier RF-4
RF-4D
Type: Motor sailer
Design country:

FranceFrance France

Manufacturer:

Sportavia-Pützer

First flight:

November 25, 1965

Commissioning:

1967

Production time:

1967-1969

Number of pieces:

156

The Fournier RF-4 is a single-seat, aerobatic touring aircraft that was developed by René Fournier in France in 1965 and mass-produced by Sportavia-Pützer in Germany from 1967 onwards.

history

The Fournier RF-4 was a further development of the Fournier RF-3 by René Fournier from 1965. With this development, Fournier primarily aimed at restoring the aerobatic suitability of the RF-3 after it was approved for aerobatics in the summer of 1965 was withdrawn in France as a result of a crash during an aerobatic maneuver. The development of the RF-4 took place at Alpavia SA in Gap Tallard in autumn 1965. A total of three RF-4 prototypes were built at Alpavia, the first of which took off on its maiden flight on November 25, 1965 with Alpavia works pilot Bernard Chauvreau .

A prototype was used for type certification in France by Alpavia SA, where the DGAC issued the type certification as a powered aircraft on December 2, 1966. Another prototype went to Sportavia-Pützer in Germany, for which the Luftfahrt-Bundesamt (Federal Aviation Office) issued a type certificate as a motor glider on January 11, 1967 . Since the verification program for aerobatic suitability had not yet been completed at this time, the type certification was carried out exclusively for cruising flight. It was not until February 6, 1968 that the Luftfahrt-Bundesamt released aerobatics for the aerobatics-approved variant known as the Fournier RF-4D. All RF-4s previously built in Germany could be registered as RF-4Ds from February 1968. For the three RF-4s built in France, this option was not provided by the Luftfahrt-Bundesamt.

construction

Front view of an RF-4, Schmallenberg 2011

Outwardly, the Fournier RF-4 differs little from its predecessor, the Fournier RF-3. Birch and pine plywood were used in the construction. The fuselage consists of four strong straps, ribs and the plywood planking. The wing is made in one piece with a box spar and plywood torsion nose. It is connected to the fuselage with four bolts. The landing gear consists of a sprung, retractable main wheel with a brake, a tail wheel that can be steered with the rudder via springs. The wings are supported by two lightweight support brackets.

In order to achieve aerobatic suitability, the RF-4 received a new, laminated pine spar to strengthen the structural strength of the overall construction. This means that loads between +13 g and −6 g are possible with the RF-4. The ailerons were aerodynamically compensated. In addition, the bottom of the fuselage of the RF-4 was rounded for the first time, which made it easy to distinguish from the RF-3. The planking was made of Finnish birch. The maximum take-off mass of the RF-4 was 390 kg, about 40 kg above its predecessor, the RF-3. As a further innovation, the RF-4 received an electric starter system that enables the engine to be switched off and started in flight.

Production and sales

A total of 159 RF-4s were built between 1965 and 1969. Three (WNr. 1–3) RF-4 prototypes were made at Alpavia SA in Gap Tallard at the end of 1965 and beginning of 1966. The series production of the RF-4 (WNr. 4004-4157) began in January 1967 at Sportavia-Pützer on the Dahlemer Binz and ended in 1969 after the completion of 156 series machines. A detailed overview of all RF-4s built by Sportavia and Alpavia can be found at Paul Zöller: Fournier aircraft .

RF-4D, at Cotswold 2009

As with the RF-3, the RF-4 was marketed via the Alpavia SA sales office in Paris for the francophone-speaking area and via Sportavia-Pützer in the rest of Europe. In England, Sportair Aviation Ltd, founded by David Campbell, took over the marketing. Sportavia delivered almost 50 aircraft in 1967. More than half of these were destined for Alpavia and the French market. Around 10 aircraft were sold to customers in England via Sportair, while Sportavia sold the remaining aircraft in Germany and the rest of Europe. All RF-4s delivered in 1967 were only approved for cruising due to the lack of aerobatics certification. The first RF-4 with a license for aerobatics came on the market in March 1968 as the Fournier RF-4D . Almost all RF-4s built by Sportavia-Pützer in 1967 were later converted into RF-4Ds with a reduced take-off weight.

At the end of 1967 the first RF-4D was delivered to the USA, where Bert Buytendyk and Sportair Aviation Inc., based in Whooster, OH, took over the sales for Sportavia. Since the RF-4D with its Rectimo engine did not meet the American building regulations for powered aircraft, all RF-4s were approved in the USA as "Experimental Aircraft". With around 75 RF-4D aircraft, Sportavia reached its highest construction rate in 1968, of which 20 aircraft were intended for Alpavia in France and 23 aircraft for Sportair in England and the USA. Other unique pieces went to South Africa, the Philippines and Mexico. Sportavia sold more than 25 aircraft in the rest of Europe, where the RF-4 found a larger market in addition to Germany, especially in Finland.

The RF-4D became considerably more expensive abroad due to multiple DM revaluations. When it was launched in 1968, a Sportavia RF-4D cost $ 5,500 in the United States. By 1972, the RF-4D list price in the United States rose to $ 8,500. As early as 1969, this made itself felt through falling sales. From a total of only 30 aircraft still built, only 10 could be sold in the main sales markets of France, England and the USA. With the exception of individual items, Sportavia's RF-4 production was discontinued in mid-1969.

Further developments

To improve the gliding characteristics of the Fournier RF-4, Alfons Pützer had an RF-4 fuselage combined with the wing of a disc SF 27 M in 1969 . In a collaboration with the Scheiben-Flugzeugbau , the Scheiben-Fournier-Sportavia SFS-31 was created for the disk that provided the SF-27 wings and Sportavia the RF-4 fuselage. For the SFS-31 production, Sportavia made another 12 RF-4 fuselages.

Alfons Pützer had already suggested the development of a two-seater version of the “Avion Planeur” at René Fournier in 1966. For this purpose, Fournier developed the two-seat Fournier RF-5 in Nitray , which went into series production at Sportavia from 1969.

The lack of type approval of the RF-4D, which with the single igniter engine Rectimo 4AR1200, did not meet the American building regulations, turned out to be a major problem with the marketing in the USA . Pützer therefore asked Fournier to modify the RF-4 with an approved twin- igniter engine. This resulted in the Fournier RF-7 as a direct further development of the RF-4 to a purely motorized aircraft.

For several years there have been several attempts to revive the RF-4 as part of ultralight developments. The most advanced was the development of the Fournier RF4UL , which some members of the Club Fournier had been building in the prototype stage since 2010 with the support of René Fournier in France. Also in France, Eric Sandstroem has been following the Friendship F4 as a two-seater RF-4 variant in composite construction since 2010 . However, the F4 was not built. There is also no more recent information available on the CFI's RF4UL, which is under construction.

Record and special flights

  • Dawn to Dusk Contest: Winner with 1234 km in 14 hours and 21 minutes
  • East-West Atlantic crossing with an RF-4D (WNr. 4115, N1700, "Spirit of Santa Paula") by Mira Slovak in May 1968. After successfully crossing the Atlantic, Slovak crossed the US continent from the east to the west coast. During the final approach to its final destination Santa Paula in California, the "Spirit of Santa Paula" was caught and destroyed by a falling squall on May 26, 1968. Slovak had covered a flight distance of 11,700 km with his plane.
  • West-East Atlantic crossing with an RF-4D (WNr. 4064, N1700) by Mira Slovak in May 1969 in 175 hours and 42 minutes during a competition for the Atlantic crossing with small aircraft of the English magazine Daily Mail on the occasion of the 50th anniversary of the first Atlantic crossing by Alcock and Brown .
  • Alpavia works pilot Bernard Chauvreau describes numerous spectacular RF-4 delivery flights . a. Multiple Sahara crossings with RF-4D to Chad and the Congo

Technical specifications

Parameter Data
Crew / passengers 1
length 6.05 m
span 11.26 m
height 1.57 m
Wing area 11.30 m²
Empty mass 280 kg
Takeoff mass 390 kg
Cruising speed 180 km / h
Top speed 200 km / h
Service ceiling 6000 m
Range 670 km
Engines 1 × Rectimo 4AR 1200; 39 PS (approx. 30 kW)

variants

  • Fournier RF-4 - base model by René Fournier from 1965, without aerobatic approval
  • Sportavia RF-4D - aerobatic approved production model at Sportavia from 1968
  • Sportavia disc SFS-31 Milan - combination of RF-4 fuselage and disc SF 27M wing

See also

literature

Web links

Commons : Fournier RF-4  - collection of images, videos and audio files

Individual evidence

  1. ^ René Fournier: Mon reve et mes combats. Edition Sier, Jan. 2005, ISBN 978-2-9519-4580-7
  2. ^ Federal Aviation Office: RF-4D device identification sheet. Retrieved September 10, 2017 .
  3. ↑ John Taylor: Sportavia RF4 . Ed .: Jane's All the World's Aircraft Publishing Ltd. tape 1967–68 , 1967, pp. 31 .
  4. ^ Paul Zöller: Fournier Airplanes , 2017, ISBN 978-3-7460-4864-2
  5. ↑ Pilot Magazine 12.2005: Sculpture in Motion: Fournier RF4D. Retrieved September 10, 2017 .
  6. ↑ Pilot Magazine 04.2001: Sportavia Avions Planeur RF4D. Retrieved September 10, 2017 .
  7. ↑ Pilot Magazine 2011-05: Fournier RF4UL Kitplane. Accessed December 31, 2017 .
  8. ↑ Bernard Chauvreau: Vols Impunia - Intimes et libres propos , France Empire, 2015, ISBN 978-2-7048-1306-3
  9. ↑ Sportavia, 1968: RF-4D Owner's Manual. Retrieved September 10, 2017 .