Airborne Magazine

HomeArticlesPlansSubscriptionsEmail

PSS Vampire

by Hank Van der Helm

Plan No. 651

 

Plan Detail Plan No. 651
Price:
AU$32.00 plus P&H (AU$3.00 within Australia).
Moulded Canopy: AU$27.50 plus P&H (AU$7.00 postage within Australia)
Order Details
By Phone: 61 3 9333 5100
By Fax: 61 3 9333 5099
By Email: airborne@interdomain.net.au
By Mail: Airborne Plans Service:
P.O. Box 30 Tullamarine Vic, Australia, 3043
The classic twin boom aircraft was powered by a single DH Goblin jet engine which gave the Vampire a top speed of 535mph.The Vampire was the first jet aircraft to enter service with the RAAF in the late 1940s and was extensively used for jet training during the 1950s and 60s.Airborne's semi-scale PSS, (Powered Slope Soarer), Vampire is based on the T MkII two seat variant. The model requires 2 channel radio control for ailerons and elevator functions.

Construction

Cut out all the parts into kit form. Build up the wing first, followed by the fuselage, twin booms and tail area.

Wing

The semi-symmetrical wing is built upside down over the plan to keep the top spar flat across the span. Pin down the top spar over the plan and glue the wing ribs down onto it. As you do so, feed the dihedral brace between W1 and W4 and glue it in. The ribs are cut out with tabs to maintain 0 degrees incidence. These tabs are trimmed off after the basic wing structure is assembled. Glue on the aileron spar, false leading edge and then the bottom spar, (on top). Add the vertical grain shear webbs between the spars, allow glue to set before lifting the structure off the building board. 

Add the D-box sheeting and centre section sheeting to the top wing surface but not the trailing edge sheet at this stage. Do not trim off the tabs on the ribs just yet. 

Temporarily install aileron and elevator servos onto mounts inside the wing. When satisfied with the fit remove servos.

With the wing pinned flat upside down again onto the building board, glue the sheeting and caps strips onto the bottom wing surface including trailing edge sheet. When glue is set the wing will be kept rigid with the sheeting. Remove tabs and glue on the remaining trailing edge sheet. 

 

Build up and shape aileron/trailing edge strips. Install the aileron torsion rods onto the rear centre section spar. Cut the ailerons to length and hinge onto the wing. Glue the trailing edge sections. Also glue on the leading edge and wing tip blocks. Sand to shape.

Make up the dummy jet air intakes by gluing on WF1 and balsa blocks and sheeting at the wing root/fuselage junction.

Fuselage

The fuselage is built up in two half shells - upper and lower. The lower is glued onto the wing, the upper becomes a removable hatch for access to radio gear. 

Build up the underside fuselage frame over the plan. Pin down the spruce longerons, WS2, and then add formers, followed by the central keel. While the frame is still on the board, skin the fuselage with 3mm balsa planking strips. Allow glue to set. 

Lift the lower half fuselage, sand the surface smooth, then glue it onto the wing. Check carefully for true alignment.

 Cover the centre section area of the wing and lower fuselage between F2 and F4 with plastic sheet or grease proof paper. Build up the upper fuselage shell and nose cone in a similar way to the lower fuselage. Add cockpit sheeting and nose block. Carve and sand upper fuselage to shape, remove hatch section rear of F2. Add ply tongues and screws for securing top fuselage hatch.

Twin Booms

The twin booms are fairly simple to make being box structures which are glued onto the wing. The elevator pushrod feeds through the inside of one of the booms. Carefully position and glue the tail booms onto the wing.

 

Tail Surfaces

Add the tailplane onto the boom ends. Hinge the elevator onto the tailplane. The fins are glued over the tailplane and onto the boom ends. Correct alignment is essential here as there will be no rudder to trim for straight flight.

Finish and Covering

After final sanding comes smoothing and filling of the balsa structure. The model was covered in silver Solar Film. RAF roundels were cut out of Solar Trim then positioned in their respective places. Paint out the cockpit, trim the canopy, glue it on then paint the canopy frames. Install radio gear, connect up all the linkages and check for movement. Balance the model to CG position shown on plan. The model is now ready to fly.

Flying

The exciting day arrived for test flying with a good 10 15 knot wind blowing at our favourite slope site. The radio gear was switched on, controls checked and the Vampire was heaved over the edge. I allowed the model to fly out straight and level to get a 'feel' of the model. Control movement was a little twitchy due to the Vampire's small size. The model initially did not gain height very rapidly as the breeze dropped off and needed a little coaxing. 

A few gentle turns to bring it closer to the slope for stronger lift was necessary to keep the model airborne as the breeze eased a little, but after a few minutes I began to feel more comfortable with its characteristics. Having ailerons only for turning allow for a little lagging in response, especially with the downwind legs. Watch out for a slight wing drop. Keep the speed up during tight turns. The model will drop a wing if the model is stalled, however recovery is quick when speed is regained. 

 

 

In the air the PSS Vampire model looks most realistic. A swooping dive to pick up speed for a fast fly pass looks terrific. It rolls rapidly and loops tightly. Inverted flight is almost as easy as the right way up. 

I was very pleased with the Vampire in the air. Be careful when landing, avoid rough ground or rocky surfaces. A belly landing should be made on grass or sand to avoid underside damage to the model. The Vampire certainly has the character and charm of the original jet aircraft and will give many hours of fun.

Plan Detail Plan No. 651
Price:
AU$32.00 plus P&H (AU$3.00 within Australia).
Moulded Canopy: AU$27.50 plus P&H (AU$7.00 postage within Australia)
Order Details
By Phone: 61 3 9333 5100
By Fax: 61 3 9333 5099
By Email: airborne@interdomain.net.au
By Mail: Airborne Plans Service: 
P.O. Box 30 Tullamarine Vic, Australia, 3043
Airborne Plans Service: P.O. Box 30 Tullamarine Vic, Australia, 3043