Porsche Aircraft Engines
by Hal Tretbar
I really appreciate the Porsche 3.2 liter motor in my 1987 Carrera. This air-cooled, 6 cylinder boxer engine is powerful, dependable, and efficient.
Ferry Porsche (company: Porsche AG) must have liked these attributes also. In 1980 he decided to adapt it for use in General Aviation (GA). The Porsche-Flugmotor division began development of the PFM 3200 in 1981.
The PFM 3200 ran at a higher speed than most aircraft engines so a reduction gear allowed the use of common propellers. Dual ignition was added. The camshaft drive train was changed from chain to spur gears. A single-lever controlled throttle, prop and fuel mixture. Other modifications produced an engine that was quiet, reliable and fuel efficient. However, it was heavier and wider that similar competitors.
The PFM 3200 was first test flown in Ulm, Bavaria in August 1982. Two Cessna 182 Skylanes were used as test beds. In 1984 it received approval from the German Aviation authorities and from the American FAA in 1985. Regular production stated in 1987.
Porsche’s interest in aviation began in 1908. But let’s go back to the beginning.
Ferdinand Porsche was a mechanical engineering genius. He was born September 3, 1875 in Mafferdorf, Austria (now known as Vratislavice nad Nisou, Czech Republic) His family had a successful sheet metal and plumbing business. In 1893 at the age of 18 his interest in electricity led to a job with the Viennese electrical company Bella Egger. Soon he was promoted to a management position. By 1897 he had developed a wheel hub electric motor and joined the carriage building company Hofwagenfabrik Jacob Lohner of Vienna.
At the Lohner Company Porsche designed and built a series of vehicles with both two and four electrical wheel motors. The first was the Egger-Lohner Phaeton. Unveiled in Vienna on 26 June 1898, Porsche had stamped P1 on important parts signifying his first car design.
Further success came with the development of the Lohner-Porsche-Mixie Hybrid in 1901. Instead of massive lead-acid batteries he powered the wheels with a Daimler internal combustion engine driving a generator. With record breaking speed of 35 miles per hour Porsche drove a two wheel model to victory in the Exelberg Ralley. Over 330 Lohner -Porsche chassis were sold by 1906 to be used as trucks, busses, and fire engines.
According to Wikipedia, Porsche was awarded the Potting Prize in 1905 as Austria’s most outstanding automobile engineer.
In 1906 Porsche joined Austro Daimler-Motoren-Gesellshaft in Wierner Neustadt as technical director. By 1908 he had designed the first Austrian aircraft: a semi-rigid airship powered by a four cylinder air cooled engine. On 26 November 1909, a silver grey airship took flight with Porsche in the gondola. It was powered by a 100 hp, six cylinder engine that he designed.
A year later Porsche was using a four cylinder 85 hp engine of his design to win auto races. The streamlined car, known as The Prince Henry, had a top speed of 160 km/hr. It was so successful he adapted the engine for the Taube monoplane conceived by the Austrian aviation pioneer Igo Etrich
In 1916 Ferdinand Porsche received an honorary degree from the Vienna University of Technology with title the “Dr. Ing. h.c.” an abbreviation for “Doctor Ingenieur Honoris Causa.” The degree was recognition for his contributions to aviation, not automobiles.
While he was with Austro Daimler he designed other aircraft engines with up to 12 cylinders and 400 hp. His real enthusiasm was for race cars, many of which he drove himself. A 1922 race car design was so successful it won 43 of 53 races.
In 1923 Porsche transferred to Daimler Motoren Gesellschaft in Stuttgart, Germany as Technical Director. The next year he received another honorary doctorate from the Stuttgart Technical University and later was given the honorary title of Professor.
Daimler merged with Benz & Cie in 1926 to form Daimler-Benz. The products were to be called Mercedes Benz. Porsche continued to develop world class racing cars such as the supercharged Mercedes Benz SSK. After a dispute with management about developing a small lightweight car he left for Steyr Automobile in 1929. The great depression prevented any further development.
Ferdinand Porsche returned to Stuttgart in 1931 to found Dr. Ing. h.c. F. Porsche GmbH, Konstruktionen und Bertungen fur Motoren and Fahrzeugbau (designs and consulting services for engines and vehicles.) He successfully recruited former co-workers and employed his son Ferry Porsche.
True Porsche automobile fans know the rest of the car story but let’s finish the saga of Porsche airplane engines.
After WWII, Germans citizens were allowed to fly only non powered aircraft (gliders). In 1955 these restrictions were lifted by the Paris Agreements. Porsche AG soon recognized that their air cooled, four cylinder engine from the 356 sports car could be adapted for aircraft use. With necessary changes, the 1,580 cc Porsche 678 aircraft engine became available. It came in four stages with power outputs from 52 to 75 hp.
In 1958 a Porsche 678/4 engine powered the first German small aircraft to go into production post WWII. The Rheinflug RW3 was based on a sailplane design with retractable landing gear. The engine was located behind the cockpit with a pusher propeller placed in the vertical tail section. A total of 22 were built.
At this same time in 1959 a more practical and popular plane was produced by Alfons Putzer K.G. of Bonn. The Elster A airframe, named the Magpie, was powered by the Porsche 52 hp 678/3. The Elster B version used the 75 hp 678/4 engine. The C version had other engines such as a Lycoming. A total of 45 A, B, and C versions were built between 1957 and 1967. The Porsche museum now has an Elster B painted in Porsche colors.
The new Porsche PFM 3200 was certified as air worthy in 1985. Two years later Porsche began active promotion to various plane manufactures. By the end of production in 1991, 80 units had been sold.
In 1987 German manufacturer Ruschmeyer Luftfahrttechnik started production of the Ruschmeyer R 80 featuring the PFM 3200. Of the 33 built only the first three were Porsche powered because of a shortage of engines.
Starting in 1972 the French company Avions Pierre Robin produced 1300 Robin airplanes. A small number of the 1980s DA400-180 RP Remo model were powered by the PFM 3200.They were used as glider tow planes.
Limited numbers of PFM 3200s were sold to smaller companies for use in the Siebelwerken-ATG, Extra 330, and Scata TB-16.
The Mooney Aircraft Company of Kerrville Texas used the PFM 3200 as its standard engine in the Mooney M20L. The M20 is a low wing four passenger plane known for its forward angled rudder. The company showed off the M20’s efficiency and dependability by flying around the world in 1986. After six months, 100,000 kilometers, 600 flying hours, 300 take-offs and landings, the PFM 3200 ran without a hitch. Mooney constructed 40 M20s in 1988 and one in 1989.
GA, general aviation, went into a tailspin in the 1990s. The high cost of aviation gas combined with worldwide depression stymied aircraft sales. When production of the PFM 3200 ceased in 1991. Porsche continued to supply parts for a decade. But after struggling with valve spring assembly failures, they announced they would discontinue production of parts.
Porsche offered airplane owners a conversion plan to replace their PFM 3220 engines with one that was comparable. Porsche contracted with Mod Works Corporation in Florida to make the changes. A few planes were converted before Hurricane Charley destroyed the plant in 2004. In September 2007, Porsche informed the Federal Aviation Administration that is was giving up its type certificate for the PFM 3200 and would withdraw any support for it.
Disgruntled Mooney Porsche PFM 3200 owners sued Porsche for lack of support. On January 26, 2011 a Florida Federal Judge ruled that aircraft owners could sue Porsche for allegedly endangering their lives by not providing a feasible replacement for their discontinued aircraft engines. The judge dismissed plaintiffs’ claim for product liability because no one had suffered a personal injury.
I don’t know if other lawsuits were ever filed, but what an inglorious ending for a chapter of Porsche’s involvement with aviation.