Henschel 132 (oz12382)

About this Plan

Henschel 132 (Das Elektrojet). Radio control sport-scale model for electric ducted fan. Wingspan 47 in, wing area 372 sq in.

Quote: "Jet Plan. Henschel 132. Plan review and construction by Martin Lagerstedt.

Das Elektrojet, a fantastic electric model, are Martin's own words to describe this stand-off scale model of a diminutive German prone-pilot dive bomber that ivas intended to be too small for Allied AA gunners to hit. The original prototype was about to begin test flights when the factory was captured by the advancing Soviet army in 1945. This 1.2m (47 in) span model for Morley Jet-Elec or similar fan units doubles as your first ducted fan model and a_fun aerobatic trainer.

History: Das Elektrojet was my second electric ducted fan model. Everything started when I was flying my first fan model the 'Electric Fan Flyer' at a fly-in. A friend of mine asked if I could design a fan model that was easier to fly and build (the Fan Flyer is a twin boom design) I accepted the challenge and went home to look through all my magazines for a suitable subject. In one of the magazines I found an article about Chris Gold's gas turbine powered Cobrajet. Chris had based his model on the German Henschel 132. It had a pod-mounted fan and the fuselage was very streamlined, a perfect candidate for an electric conversion. Like Chris, I prefer to call this a 'cartoon scale' model.

With the Morley Jet-Elec fan unit and 8 cells I had 400 grams of thrust in my Fan Flyer so I decided on a target weight of 1200 grams and a 1.2m wingspan. I also decided to use the same wing profile (section) as my Fan Flyer. The wing has a flat underside and you build the wing direct on the bottom planking.

Building the wing: Glue the wing bottom planking, lightweight 1.5mm (1/16) balsa, together and mark the positions of the wing ribs. Glue the leading edge, 6 x 8mm (1/4 x 5/16) balsa and the trailing edge, 4 x 6mm (5/32 x 1/4) balsa to the planking.

Fit the wing ribs between the false leading and the trailing edges by cutting the rear of the ribs. When glueing the rib closest to the wing root, use the dihedral template to get the correct angle on the rib. Sand down the rear of the ribs. Strengthen the wing fan mounting according to the plan.

Build both halves, remembering to build one left and one right! Glue together the wing halves with a dihedral doubler (2 mm plywood). The dihedral should be 50mm at each wingtip. Install the aileron linkage according to plan and fill the gap between the linkage and the rear of the wing with soft balsa. Sand to shape.

Plank the top of the wing with light 1.5mm (1/16) balsa. Trim the planking to shape and glue the front leading edge in place. Build the ailerons (light balsa) and mount them with hinges. Reinforce the wing joint with 1 or 2 layers of glass fabric, or tape, and epoxy. Drill holes for the 4 mm nylon bolts and glue a dowel in the front of the wing.

Fuselage: Cut the 2 fuselage sides from 2mm (3/32) medium balsa. Glue the 1.5mm (1/16) plywood doublers and 10 x 10mm (3/8 x 3/8) balsa triangle strips according to plan. (Remember again to make one right and one left side - and don't say I didn't warn you!)

Cut the formers. Former 1 is a lamination of 1mm ply + 1mm balsa + 1mm ply. (If you cannot obtain 1mm, use 1/32). Glue formers 1 and 2 square to one of the fuselage sides. Then glue to the other fuselage side. When the glue is dry, glue the rest of the formers in place. Make sure that you get a straight fuselage. Plank the bottom of the fuselage with 2mm (3/32) balsa, crossgrain. Use harder balsa at the front and softer at the rear of the fuselage. Glue the medium balsa nose block in place and sand to shape. Install the two push rods to the elevators and glue in an empty snake outer tube for the antenna.

Plank the top of the fuselage with 1.5mm (1/16) balsa behind the wing (crossgrain) and 10mm (3/8) balsa in front of the wing. Plane and sand all corners/edges so you get a streamlined and rounded fuselage. Build the battery hatch/canopy from balsa. The landing skid is made of balsa/plywood or balsa/carbon fibre.

Tailplane: The tailplane (stabiliser) is made of 3mm (1/8) light balsa. Crack and glue the tail at the angle shown in the plan. Strengthen the joint with balsa or glassfibre or carbon fibre and epoxy. The fins are glued to the tailplane and joints strengthened with triangle strip.

Assembly: Drill a hole in the fan so you can fit a wheel collar with an outside diameter of about 8mm (5/16). When the fan is placed in the wing secure the fan with a 3mm screw (into the wheel collar) from the bottom of the wing. Use a ply disc washer. A shroud can be build from foam around the fan unit according to plan (not essential). Don't forget to cut a hole in the wing for the motor cables.

Equipment: The fan motor used in my model was a Kyosho MEGA, Part No.2475, 2 x 20 (20 turn, double wind). The elevator servo is placed on servo mounts as shown on the plan. The speed control (BEC in mine) can be placed beside or in front of the elevator servo. The aileron servo should be a mini (like a Hitec 101) and is mounted in the wing.

A battery of 7 or 8 cells is placed on a sloping ramp of 1mm plywood. The CG is adjusted by moving the battery. When you have found the right CG, cut a piece of foam to size to locate the battery. The receiver is placed under the ramp in its own foam pack.

Covering: My original 132 had its wings and tail covered in Solarfilm. The fuselage was covered with light glass cloth and epoxy but any light covering will do. The markings were made from Solartrim.

Flying: I designed this plane to fly as a fan trainer. My first fan model was faster and more aerobatic but it needed a very good hand launch to get airborne due to the small size and its high wing loading.

Das Elektrojet is much easier to launch. Just launch, let it build up some speed and it will start to climb. Once it is away it's great fun to fly. Keep the speed up and rolls and loops are possible (requires a small dive). One of my favourite manoeuvres is a high altitude dive towards the field, make a very low pass and with the help of the speed climb steeply.

The model is very easy to fly. If you have flown an aileron trainer before you should have no problem with this model. It is very stable and can be flown quite slowly because of its low wing loading. The model will fly on 7 and 8 cells. You get longer duration with 7 but 8 is more fun!

Das Elektrojet will glide very well without power. When it is time to land you have to come in very low if you want to land before the end of the field.

I have flown Das Elektrojet for two years now and I still enjoy it. With 400 grams of thrust on 8 cells you don't have fighter performance but I think the scale speed is similar to the early German jet planes and the high-revving fan creates a sound/scream that is very close to a real jet engine (or vacuum cleaner!)."

Henschel 132, Electric Flight International, January/February 1997.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction