05/27/2017. Remarks by Walter van Tilborg and Johan Visschedijk: "The Busard (Harrier) series were based on the one-of-a-kind PF.204 built some twenty years earlier.

PF.204. Max Plan of Argenteuil (near Paris, France) was an aeronautical engineer and at the time chief of the supersonic tunnel at nearby Meudon. Assisted by Jean-Paul Fromage he designed and built a single-seat aircraft of all-wooden construction, intended to attack the FAI world speed record for aircraft under 1,102 lb (500 kg). Power plant was a 75 hp Minié 4 DC four-cylinder horizontally-opposed air-cooled engine, driving a two-blade fixed-pitch propeller.

PF.204 (F-PBGE) (Johan Visschedijk Collection)

Initially registered F-WBGE (c/n 01), the PF.204 first flew on June 5, 1952, after receiving its CofA it was reregistered F-PBGE on September 16, 1952. The registration was cancelled on December 3, 1971.

PF.214. By 1955 the PF.204 had a new engine cowling, an enlarged cockpit and some other minor modifications. Reportedly the aircraft was redesignated PF.214, although that is not shown on the aircraft nor on the French aircraft register.

PF.215. Intended modification with a 90 hp Continental C90 engine, which never materialized.

MP 204 Busard. In the early 1970s, Robert Lefebvre of Darnétal (near Rouen, France), at the time the Secretary of the RSA, reworked the PF.204 design to make it suitable for amateur construction. The modernized version differed mainly in having a lighter overall construction, a slight increase in overall dimensions (although with the same wing area), a more streamlined canopy and engine cowling, and a turtle deck. The first example was built by Lefebvre together with students of the Albert Camus Technical School at Rouen. Powered by a 65 hp Continental A65 and registered F-WTXT (c/n 01), Lefebvre took it to the air for the first time on December 9, 1973. After twenty flying hours it was modified to MP 205.

MP 205 Busard. Very similar to the MP 204 but strengthened for more powerful engine up to 125 hp.

MP 207 Busard. Refined version of the MP 205 with a slight increase in overall dimensions.

Lefebvre sold a considerable number of plans for the Max Plan MP 205 and Max Plan MP 207, but only a few are known to be completed.

MP 205 (F-PTXT c/n 01) (Regis Biaux Collection)

MP 205 c/n 01. The sole MP 204 (F-WTXT) modified by Lefebvre, fitted with a 90 hp Continental C90 engine. After receiving its CofA it was reregistered F-PTXT on February 25, 1975. Still owned by Lefebvre, the aircraft was cancelled from the French register on Augustus 31, 1994.

MP 205 (F-PYEL c/n 02) (Regis Biaux Collection)

MP 205 c/n 02. Built by Louis Boimare of Evreux, fitted with an 100 hp Continental O-200-A engine. First flown as F-WYEL on October 19, 1977, reregistered F-PYEL on February 27, 1978. On August 31, 1983 the aircraft was sold to Felix Chaintreuil of Valentigney, on October 14, 1994, the Association Vertical Evolution at Beaune became the new registrant. The aircraft was cancelled from the French register on November 21, 2016.

MP 205 (F-PYFQ c/n 17) (Regis Biaux Collection)

MP 205 c/n 17. Built by Christian Boulingue of Prigny, fitted with an 100 hp Rolls-Royce/Continental O-200-A engine. First flown as F-WYFQ in March 1979, it was reregistered F-PYFQ on August 2, 1979. Subsequent owners were Pascal Bonnet of Labergement-Sainte-Marie (April 25, 1988), Jean Larrieu of Eyragues (January 18, 1996), and Bruno Langou of Sainte Pazanne (August 5, 1999). The aircraft is still registered.

MP 205 (F-PRJR c/n 25) (Henk Wadman Collection)

MP 205 c/n 25. Built by Bernard Marichy, fitted with a 90 hp Continental C90-8F engine. First flown as F-WRJR on November 20, 1995, the aircraft was reregistered F-PRJR on July 24, 1996, and is still active.

MP 207 c/n 19. Built by James Mangold and Stéphane Ballandin of Tilly, fitted with a stock Rolls-Royce/Continental O-200-A engine of 100 hp. First flown as F-WYAS on September 22, 2000, the aircraft was reregistered F-PYAS on March 6, 2001. In August 2004 it was re-engined with a modified Continental O-200-A of 100 hp, this had its crankshaft, rods and pistons balanced. On June 25, 2013 the aircraft was sold to Stanislas Damiron at La Perrire. It is still registered.

MP 207 (F-PZSI c/n 20) (Regis Biaux Collection)

MP 207 (F-PZSI c/n 20) (Walter van Tilborg Memorial Collection)

MP 207 c/n 20. Built by Joseph Rieth of Riedisheim, fitted with an 100 hp Continental O-200-A engine. First flown as F-WZSI on November 25, 1984, it was reregistered F-PZSI on January 4, 1985. Subsequent owners were Beoit Derval of Trégueux (July 4, 2005), Francois Taboureau of Chambourcy (April 1, 2009), and Bertrand Plantin, Carrières-sous-Poissy (August 12, 2015). The aircraft is still registered.

MP 207 c/n 44. Built by Jacky Barbeau of Thuré, assisted by Claude Verna. First flown as F-WBNV earlier in 2006, it was reregistered F-PBNV on July 21 of that year. The aircraft is still registered."