Cassutt (oz10123)


Cassutt (oz10123) by NR Blackwell 1991 - plan thumbnail

About this Plan

Airmark Cassutt. Radio control scale model racer for .60 engines. Scale is 1/4.

Quote: "Go quarter-scale with NR Blackwell's racer for .60 motors - just 45 in span!

In 1954 Captain Tom Cassutt designed the Cassutt Special, a single-seat racing aircraft. Following the success of the prototype many were constructed by home builders in the US. In 1969 Airmark Ltd started to produce the Airmark Cassutt in the UK. Two derivatives were produced, the IIM and IIIM, the main differences being in the width of the fuselage and of the thickness of the wing.

Both types were powered by 85-90 hp engines, normally of the Rolls Royce Continental variety which gave a top speed of around 200mph. The fuselage, fin, rudder, tailplane and elevators were constructed of welded steel tube, the wings had built up ribs and laminated spruce main spar. The cowl is from fibreglass and metal and the whole unit was reputedly stressed to + or - 12 G.

Building your Cassutt. Nothing too complicated here, but I would expect anybody building this model to be reasonably experienced at building from plans as it is not really suitable for a second or third model. Cut out all parts and make a kit. Laminate sides and doublers and add top 1/4 in sq balsa. Attach 12 and F4 and undercarriage plate. When dry add the 1/2 x 1/2 in hard balsa servo tray mount. Next add formers F5-8 and 5/16 x 1/4 in fin post. Now add fin core (note offset) and 1/4in sq balsa spine and 1/4 in sq spruce keel. Next epoxy in F1 and D fillets. While that has been going on it will have been no hardship to build two wing panels.

When the fuselage is dry check the wing panels against the fuselage. If all is OK put the panels back on the building board and sheet the top and bottom with 1/64 ply (if you have used foam wing panels they should be fitted with spars as per the built up wing with 2-7/8 in of the spars protruding from the inboard end of each panel and 1/16 balsa tip ribs on the outboard end).

Next add the 1/2 in sheet wing tips noting that they stop 50mm short of the false TE. Back to the fin. Add two pieces of 1/4sq x 1/4in long spruce to the rear of F8, then add the 1/4 x 1/8 top and diagonal rod to the fin and finally attach FR3. Now we return to the wings. Put the aileron torque rods into the false TE and epoxy the wings into the cutouts in the fuselage making sure everything is aligned correctly. When dry, sheet in the top of the rear fuselage and the areas just to the rear of the cockpit..."

Cassutt, RCM&E, January 1991.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.


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Cassutt (oz10123) by NR Blackwell 1991 - model pic

  • (oz10123)
    by NR Blackwell
    from RCME
    January 1991 
    45in span
    Scale IC R/C LowWing Racer Civil
    clean :)
    all formers complete :)
    got article :)
  • Submitted: 18/05/2018
    Filesize: 745KB
    Format: • PDFbitmap
    Credit*: Circlip, RFJ
    Downloads: 1828

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Cassutt (oz10123) by NR Blackwell 1991 - pic 003.jpg
Cassutt (oz10123) by NR Blackwell 1991 - pic 004.jpg

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User comments

Hello guys! Just one question: are there any pictures of ribs on the plan, or do you dont need them? cheers
Sebastian - 23/10/2021
Unfortunately the designer chose to comment on the notes "Building your Cassutt"
Aerofoil section only in side elevation.
Regards Ian. (Circlip)
Circlip - 23/10/2021
You don't need them. One is shown and the wing's rectangular.
Hubert - 23/10/2021
Thank you very much for your reply, Hubert!
Sebastian - 25/10/2021
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