A single-seat racing monoplane (first flown 1975), developed from Max Plan MP.204 of 1952.
Seats: 1.
Engine: 85-100 hp.
Span: 19’8”.
Wing area: 64.5 sq.ft.
Length: 17’6”.
Max wt: 760 lbs.
Empty wt: 527 lbs.
Cruise: 125 kts.
Lefebvre MP 205 Busard
Aircraft
Lefebvre, Robert
France
Robert Lefebvre markets plans to construct the MP.205 Busard single-seat racing monoplane (first flown 1975), developed from Max Plan MP.204 of 1952.
Lefebvre La Mouette / Gull
Designed and built by Louis Lefebvre in 1911 in France, the “La Mouette” (Gull) monoplane had telescoping wing panels.
Span: from 19’8″ to 32’10”
Length: 27’9″
Weight: 880 lbs
Lefebvre 1911 monoplane
A monoplane with long-span wings and up-turned wing tips, a design of Louis Lefebvre. It was entered for the 1911 Concours militaire in France, and tested by Sadi-Lecointe at Chartres, but didn’t participate.
Span: 55’9″
Length: 39’4″
Lee-Richards Monoplane
Lee and Richards built another aircraft, a monoplane with a conventional fuselage and tail surfaces and a 6.7 m (22 ft) diameter annular wing. The first flight on 23 November 1913 ended abruptly when the tail heavy aircraft stalled and crashed into telegraph wires without injury to pilot E. C. Gordon England. Rebuilt, the 80 hp Gnome engined Lee Richards Annular Monoplane proved easy to fly. With pilot and passenger aboard it would take¬off at about 48 kph (30 mph) and had a maximum speed of 137 kph (85 mph). The original aircraft flew for 1028 hours during ten months of testing and was the first truly successful flying saucer. Two more Lee-¬Richards Annulars were built early in 1914 for the Gordon Bennett race, and after World War I Tilghman Richards tried to interest the Air Ministry in his unusual design, without success.
Lee-Richards Biplane
Englishman, G.J.A. Kitchen of Lancaster, patented a circular or annular wing and sold the rights to Cedric Lee, who built an annular winged biplane powered by a 50 hp Gnome rotary engine in 1911. This ‘Kitchen Doughnut’ was wrecked by a gale during tests. Lee and his engineer Tilghman Richards continued to experiment with gliders and with wind tunnel test models at the National Physical Laboratory and soon discovered that the circular wing had some very desirable properties. It continued to provide lift at extreme angles of incidence, and had a gentle stall. Furthermore, a round wing could have a span or diameter less than half that of a conventional surface of the same lifting area.
In 1912 the Lee-Richards annular wing was a circular planform with a hole diameter half span. The powered portotype was a biplane, and they tested it at Middleton Sands, Heysham in 1911. This was supposed to be a very stable configuration, and a later version flew for 128 hours, but the prototype had run into a gully, and then been destroyed when the hanger blew down in a gale. They had been changing the leading-edge camber shape, but were unable to decide which was best, so before rebuilding they tried two models, span 4.7 ft, flown indoors. Extra camber seemed to give a flatter glide angle, but the other person said that this was due to better launch technique. So they went full scale.
The glider was a biplane, but the upper wing was only the front half of the circle. Elevators behind the wing were also operated differentially for roll control and a fin and rudder were added later. The pilot’s seat was in the hole, and the breeze.
Launch was by catapult from a track, pulled by a rope tied to a dropping weight within a tall tripod. The site was Sellet Banks, an east-facing slope 117 feet above the River Lune near Kirby Lonsdale.
The glider made many successful glides. It was stable and controllable, was banked into turns, and even taken through the stall to 30 degrees nose up, when it pancaked steadily. They often flew in winds of 20 mph, and even 40 mph.
On the final day of flying at the end of trials in December 1912, Cedric Lee made a soaring flight in a strong wind. Cine film was taken, used in the opening clips of “Those Magnificent Men”, and stored in the Science Museum.
A non-flying replica of the powered version is at the Newark Museum.
Wingspan: 22 ft
Wing area: 400 sq.ft
Empty weight: 215 lb (later 390 lb)
Gross weight: 710 lb
Glide ratio: 1-8
Lee L-2P-T / Springfield JM2P
The Lee L-2P-T N353V was a two-place, open cockpit monoplane, powered by a 60hp LeBlond 5D.
Lee Inman sold the Lee L-2P-T in 1930 and it was renamed the Springfield JM2P of the Springfield School of Aviation, Springfield OR., USA.
A second, biplane Continental-powered version, was built in 1931 as the MacManaman Baby Fleet.
Leduc 0.22
Development of the Leduc 0.10 continued with the larger Leduc 0.21, then the Leduc 0.22 Mach 2 interceptor which incorporated a SNECMA Atar D3 turbojet within the athodyd to allow the aircraft to take off under its own power and then accelerate it to a speed at which the ramjet would ignite.
This was not achieved with the 0.22, for although flown on turbojet power for the first time on 26 December 1956, and later making more than 30 test flights with the turbine engine, the ramjet was not tested. This resulted from withdrawal of government financial support, because of economic stringencies, and the project was abandoned in 1957.
Leduc 0.21
Development of a aero-thermo-dynamic-duct or athodyd ramjet engine continued with two examples of the larger Leduc 0.21 of improved design (L.021 -01 and –02), the first making its initial flight on 16 May 1953.
These proved to be successful, demonstrating a maximum speed of Mach 0.87 and attaining an altitude of 20,000m. Development then began of the Leduc 0.22 Mach 2 interceptor.
The Leduc 0.21 was larger than the 0.10, and with a ramjet delivering 14,330-1b (6500kg) thrust at a speed of 621 mph (1000 km/h).
Leduc 0.16
Two more examples of the Leduc 0.10 were built, the first an identical 0.10, the other differing only by having two wingtip-mounted turbojet engines to accelerate the aircraft to the ignition speed of the ramjets. This last aircraft, designated 0.16, was first flown on 8 February 1951, but the turbojet engines were later removed.
The Leduc 016 was developed with wingtip mounted Marbore I.
