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Leo Powning's Jodel project

  

 

Jodel D18 'Sovereign' (19-3149)

AUF Amateur Built (Experimental Category) from plans. The Jodel D18 'Sovereign' is a side by side two seat aircraft of wood (Douglas Fir or Hoop Pine) and plywood construction. The French D18 is designed by Jean Delemontez, his Jodel designs range from single seat to 4 seat aircraft. See www.jodel.com for the full range. All have the characteristic cranked wing. Jodels are very popular in Europe where thousands have been built.

Build time is around 3000 hours. English language plans are available from:
Frank Rogers
35 St Pauls' Crescent
Liverpool NSW 2170
Australia

Jodel D18 specifications with a Jabiru 80 hp engine -
      •   Wing span: 7.50 m
      •   Length: 5.7 m
      •   Height: 1.93 m
      •   Wing area: 10 sq.m
      •   Cabin width: 1 m
      •   Fuel capacity: 100 L
      •   Seats: 2
      •   Engine: Jabiru 2.2 L
      •   Power: 80 hp @ 3300 rpm
      •   Empty weight: 250 kg
      •   Max weight: 450 kg
      •   VNE: 135 knots
      •   Cruise speed: 100 knots
      •   Climb (MTOW): 680 fpm
      •   Stall speed (flaps down): 35 knots
      •   Aerofoil: NACA 43013.5
      •   Range: 700 nm
      •   Ultimate design load: +6.6g, -3.3g.

Jodel instrument panel


Instrument panel:

Flight instruments are ASI, altimeter, compass, slip/skid. Instrument costs exceeded my budget, the blanked out hole is for a VSI which I'll install later. The engine instruments are tacho in the centre of the panel and on the right are oil temperature and pressure, cylinder head temperature, rear tank fuel gauge (I'll use a float and wire on the front tank), voltmeter and fuel pressure gauge. The panel is hinged for easy servicing access.


Jodel fuselage

Fuselage/Engine:

I am fitting a 80HP Jabiru 2200cc. The 2200 only weighs 130lbs including accessories so is well forward to maintain the required centre of gravity. The forward position makes it much easier to install and service items on the firewall. The engine and instrument fitout is much easier to do with the front turtle deck left off.

Jodel cowling

Engine cowling:

November, 2001. The galvanised sheet metal firewall is separated from the wooden fuselage with a Fibrefax fire and heat resistant blanket. The engine cowling is constructed from a fibreglass nosebowl supplied by the Jabiru factory and continued back to the fuselage attachment points in sheet aluminium. The supporting cowling frame is made up of aluminium angle cantilevered from the fuselage. 'Cleco' temporary fasteners are used to hold the aluminium covering in place during fitting and prior to final riveting of the aluminium sheet to the supporting frame.

Jodel cowling

November, 2001. The finished upper cowl is easily removed for daily inspection. The rear is attached to the fuselage with four Camloc fasteners; the front is attached to the nosebowl of the lower cowl with over-centre latches. It is seldom necessary to remove the lower cowl, its frame is fastened to the fuselage with bolts and 'anchor' nuts.

Jodel rear turtle deck

Rear turtle deck:

November, 2001. Rear turtle deck partly covered with plywood. All interior surfaces are varnished to prevent moisture damage to woodwork. VHF 1/4 wave whip antenna for the aviation comm band has been fitted, one of the four aluminium strip radials for the antenna ground plane can be seen in the photo.

Jodel fuselage

June, 2002. Fuselage and empennage covered and painted. Engine cowling fitted and painted. Windscreen fitted but canopy remaining to be done – fellow D18 builder, Lachlan Wishart, is kindly making a mould for the acrylic canopy to then be formed at a commercial plastics workshop with the necessary oven and equipment. Last tasks are to cover and paint the wings and fit the undercarriage.

Fuselage and wings

August 2002. Final fit of wing to fuselage before covering wing. Son and co-owner in cockpit, helpers behind fuselage with another D18 builder and AUF member Lachlan Wishart in front.

Wing treatment

October 2002. Inverted wing varnished with 2-pack polyurethane floor varnish which is impervious to Polyfiber process solvents and beginning covering with Polyfiber 2.7 ounce fabric, then Polybrush base coat, Polyspray ultraviolet blocker, and finally Polytone color coat.

Wing treatment

December 2002. Wing covered and painted with Polybrush base coat and Polyspray ultraviolet blocker.

Canopy

January 2003. Fitting covering to sliding canopy.

Canopy

January 2003. Fixing undercarriage to wing after the wing was attached to the fuselage at Lethbridge Airpark, Victoria. The one piece wing was transported in the furniture van in the background. The BMX wheels on legs attached to the engine mount bolts enabled the fuselage to be easily moved around. Here they are shown rolled up onto car ramps to give enough clearance for the undercarriage legs to be fitted to the wing.




  Mademoiselle Marguerite

June 2003. Taxi test after completion; and Mademoiselle Marguerite is ready for inspection by AUF Amateur Built inspector."

Mademoiselle Marguerite

January 2004. My D18 on final approach taken by fellow D18 builder Lachlan Wishart. I am very pleased with the performance of the Jodel – here is a short report:

"The Jodel D18 airframe/Jabiru 2200 engine with Jabiru 60" x 42" wooden prop is an excellent performing combination. Climb rate 'one-up' with full front 35 litre tank is 1000 feet per minute and 2800 rpm gives 100+ knots cruise. Stick forces are light at 100 knots. I will gain another few knots after I streamline the 60 mm square u/c legs. Take-off distance to clear a 50 feet obstacle is approximately 500 feet. I tried going downwind at 100 knots in the 500 ft circuit at my home strip at Lethbridge Airpark in Victoria but found it too fast to allow me enough time to get things settled down on final unless I have a long final so I will reduce downwind speed to 80 knots. 55 knots over the fence allows a landing within 500 ft. I've learned not to come in hot and high with the D18; even with full braking I almost used up our 3500 ft strip. I can be hot and high with my Minimax and still get in ok because of the Minimax's high drag but not the D18 with its lower drag airframe and low wing which increases float.

The differential heel-operated mechanical shoe brakes work fine; I can lock one wheel and turn the aircraft around in a small space which is very handy after backtracking down the strip and needing to turn for takeoff. The low cloudbase in the area over the past few weeks has prevented me getting enough altitude to safely check stall speeds. I have to re-introduce pre and post takeoff, downwind, and final checks. Apart from pre-flight and radio calls I had no need of them on my simple Minimax which does everything at the same speed but I need to on the D18 with its flaps and speed settings. I've already found myself on downwind at 90 knots with the flap I had set for the previous 'touch and go' and forgotten to retract after takeoff. I am chasing some radio squeal on transmit caused by RF feedback from the radiated signal getting into the electret microphone's amplifier in the headset. Will try a ferrite ring on the headset lead in case it's acting as an antenna. I'm very pleased with the D18, it suits my needs perfectly."

... Leo Powning

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