The Jodel D.11 is a French two-seat monoplane designed and developed by Société Avions Jodel in response to a French government request for a low-wing aircraft for use by the nation’s many emerging flying clubs.
More than 3,000 examples have been built and flown.
Designers Édouard Joly and Jean Délémontez based the design on two of their earlier projects; they combined the wing of the projected D.10 with a lengthened and widened version of the D.9 fuselage. The first example flew on 4 April 1950. Of conventional tailwheel configuration, the D11 featured a fixed, spatted undercarriage, and accommodated pilot and passenger side-by-side. The wing panels outboard of the landing gear struts had a marked dihedral. Various powerplants were installed, typically Salmson 9, Continental O-170 or Continental O-200. The aircraft uses all-wood construction with a single piece box-spar.
D.11s were licence-built by a number of manufacturers in Europe and elsewhere, including Wassmer, Aero-Difusión, and Falconar Avia. Many examples were also home-built with plans provided by Falconar.
General characteristics:
Crew: one
Capacity: one passenger or student pilot
Length: 6.2 m (20 ft 4 in)
Wingspan: 8.2 m (26 ft 11 in)
Wing area: 12.7 m2 (137 sq ft)
Empty weight: 340 kg (750 lb)
Gross weight: 620 kg (1,367 lb)
Powerplant: 1 × Continental O-200 4-cyl. air-cooled horizontally opposed piston engine, 75 kW (101 hp)
Performance:
Maximum speed: 210 km/h (130 mph; 113 kn)
Range: 900 km (559 mi; 486 nmi)
Rate of climb: 4.33 m/s (852 ft/min)
Jodel D11 ZS UEK-a Labour of Love
By Willie Bodenstein
Stewart Clegg started his career in aviation at Comair where he did his apprenticeship as an aircraft mechanic. At the time he had been looking around for an aircraft to build. Initially he looked at the KR2 but that was just too marginal and after doing some research he decided on the Jodel and acquired a partially built one that he kept in the back of the hangar at Comair. In 1979 he got his PPL at Oribi, Pietermaritzburg and today has besides the Jodel got the Tiger Moth, Whisper, Cessna 140, 172, 182 Gruman Traveller, Cherokee 140,160 and 181.
The Jodel followed him when he moved to Celair where he assisted with the design of the CelStar aerobatic glider. He left Celair a year later and the Jodel went with to Resitex where he worked on the cowlings for the turbine conversions on the DC3/C-47’s. When Resitex went insolvent Stewart joined Episilon Engineering with the partially completed Jodel in tow. Then UEK came on the market. By then Stewart had realised that he would probably never finished the partially built one and he took a loan from a bank and bought UEK.
Based at Zyferfontein she needed some work to get into flying condition and Stewart spent the next six months traveling between Pretoria and Zyferfontein to get her ready for her ferry flight to Fly-in Estate. Jeff Birch flew her to her new home and then later gave Stewart his conversion. Whilst at Fly-in Estate UEK got a new cowling and bubble canopy that Stewart had designed. John Mcsher did the test flying and Stewart took her to a couple of the EAA Fly-ins at Margate. After a couple of scary moments and engine failures Stewart saved up, took another loan and bought a O 235 l2C Lycoming refurbished for UEK by Fanie Viljoen.
With the engine fitted, part of the engine run in flight was a cross country trip down to Paradise Beach, Jeffreys bay. Stewart and family had moved down to Paradise beach to start developing and manufacturing the Whisper motorglider kits. They would remain there for ten years. Whilst there, a broken wing rib was noticed whilst flying. Upon landing the wing fabric was cut open and indeed there was a broken rib. The broken rib was repaired and before recovering, the wings were load tested to 3.5Gs. In the 10 full recovering and a new coat of paint as well as a new reshaped cowling and an extra 45 litre fuel tank behind the seat.
In 2010, Gregory, Stewarts son was in matric. Greg had ambitions to become a commercial pilot and did not plan on getting a university degree. However, the school of engineering at Nelson Mandela Metropolitan University (NMMU) had a design competition for grade 12 scholars to win a bursary to study in the field of engineering at NMMU. The competition was to design, document and build a RC sized electric car. The car was to be powered by a 9v battery, it had to race down a 1.2 m track, hit a wall and race back. The cars were to race against each other to determine the fastest car.
Greg spent the lengthy school holidays, due to the soccer world cup, building his car. The race happened after the school holidays at the university. Greg ended up coming first and winning himself a full tuition bursary to study and Greg chose to study Mechanical engineering. Later that year, Greg under the guidance of Stewart, started fitting dual controls to the Jodel. The Jodel needed a throttle and brakes on the instructor’s side.
In 2011 Greg started his first year at university and later that same year he started his PPL at Algoa Flight Centre on the Jodel. Greg worked as a waiter on weekends and holidays to fund his PPL and was sent solo on UEK at around 8 hours. Because of his studies and lack of funds it took him over one and a half years before he got his PPL in 2013. He currently has about 190 hours on the Jodel and also rated on the Sling.
In 2013 the family relocated back to the big smoke. Stewart returned to Episilon Engineering and UEK found her way back to Fly inn. Greg, with his studies mostly completed, joined the family in Gauteng to complete his practical at the same company where Stewart is working. UEK in the meantime got a new set of undercarriage as there was quite a bit of corrosion on the old set. In 2014 she also got a set of spats that both Stewart and Greg made. The final task, which they eventually got around to doing, was making the fairings to fair in the spat and gear leg interface.
All their personal touches make UEK not only a very unique example of Jodel but arguably one of the prettiest in the country. There is talk that she may soon sport a new colour scheme.
The Jodel was designed by Societe Avions in response to a requirement by the French government for a low-wing aircraft for use by the nation’s many emerging flying clubs. Designers Édouard Joly and Jean Délémontez based the design on two of their earlier projects; they combined the wing of the projected D.10 with a lengthened and widened version of the D.9 fuselage. The aircraft uses all-wood construction with a single piece box-spar and the first example flew on 4 April 1950.
The Clegg’s D11 weighs just under 440kgs, can take 2 medium sized adults, 30kgs of baggage and 110 litres of fuel. She will still take off in 400 meters on a warm day and climb at 600 fpm. UEK, like most Jodels, doesn’t have flaps. “Flaps”, Stewart says, “would be a nice to have just for the landing phase. Landing with any excess speed she floats forever. Approach speed is 55 mph where she will land within 300 to 400 meters. We cruise around at 115 knots indicated burning 18 LPH on average. At the coast at full power we will do 135 knots.”
“She will stall at about 45 mph, where she gently mushes down. She would drop a wing in the past but this has been corrected by the inboard stall strips as well as the Vortex Generators (VGs). The VGs were first fitted in a quest to tame the stall but they weren’t the magic that they claimed to be. Stall strips were later fitted at the root of the wing to pre stall the inboard section of the wing first, while the tips keep flying”
UEK with her distinctive cranked wing attracts attention where ever she goes. Like Greg’s favourite aircraft the Mustang and Stewart’s the Spitfire she just looks right. Asked what is next Greg said: “Both my Dad and I would like to design and build a composite tandem two seater that would cruise at over 180kts and be fully aerobatic. One day when there is time and money…..”
I spotted this interesting tail-dragger a couple of weeks back, being lovingly brought back to flying condition by a father and son team. The wing form immediately rang a bell in my head, as it was very similar to the Robin which I was taken for a flight in, during a visit to France.
The Jodel is also a French design, and was built off plans here in SA (I really admire the commitment it takes to do this!), The plans date back to the late 1940’s, and it is constructed entirely from wood and fabric.The D11 is a two seater, based on the first example in the Jodel series, the D9.
The Jodel is very unique in its design, featuring a one piece cranked wing. The cranked wing allows for an easier and lighter build. The main wing is built on a flat table, with a straight single piece box spar. This allows for simple and easy jigging. The bent outboard section provides the dihedral for stability and has the washout to prevent wingtip stalling.
This particular Jodel D11, ZS-UEK build, was initially started in the Durban area in the mid 1960’s. The partially built aircraft changed hands, and was eventually completed by Willem Mante. Stewart Clegg, who would eventually own it, was already busy trying to complete another partially built Jodel, which he had been working on for a number of years (cue my point that these sorts of projects require a lot of patience!). This partially built Jodel, like a faithful family pet, followed him, as he moved around the country, from job to job. When UEK appeared on the market in the mid 90’s, Stewart could not resist, and bought her.
I asked Greg, Stewart’s son, to tell me more about the build:
‘UEK is powered by a 115 HP O-235 Lycoming, which by Jodel standards is quite powerful. The Original D11’s were powered by 60 to 90 Hp motors. Being a French design from the 50’s, the Jodel is on the small side inside the cockpit.’
‘UEK is very basic. She features a basic instrument panel (ASI, ALT, VSI and the nessicary engine monitoring instruments). She is a taildragger with a full castoring non steerable tailwheel. The tailwheel can lock, and this is used for take off and landing. She has a fixed pitch prop and has no flaps.Take off happens around 60 mph and she will climb out at 1000 fpm with two on board. She will use around 300 meters of runway. UEK is Rather “clean” and will cruise at 115 KIAS sipping about 18 LPH. Full throttle she will reach 135 KIAS.
Without flaps and being so clean, landing and approaching needs some planning. She approaches at 60 mph and 55 mph over the fence. Approaching slightly too fast she tends to float quite a bit.’
‘Stalling is a non event. She lets go at about 40 mph and will stay fully stalled, with the ailerons still being effective. She did in the past have a tendency to drop a wing. This has been corrected with stall strips on the root of the wing, forcing the inboard section to stall first while the tips stay flying.’
‘UEK has an endurance of 6 hours, she will carry two people and all their baggage for the week and she will still get airborne in 400m on a warm day up here at altitude.
I cannot help but admire the in-depth knowledge that you can gain from building an aircraft, I am sure it can only make you a better pilot! Thanks for the insight Greg.