T11 Seal (oz3012)

About this Plan

T11 Seal. Free flight sport seaplane, for 2.5cc power.

Quote: "Latest model in the series is a biplane of 'antique' lines and simple design, known as Seal. To fool some onlookers, the Seal has a pilot and observer sitting in their open cockpits, the pilot looking steadily ahead, the observer on his side peers at the things down below. Of course, both Jack and Jim, properly moustached, each wear a red scarf. Having generous flying surfaces, the size of the model is rather small with a wingspan of 49-1/2in, the simple shape reducing the weight to 35 ounces. Compact in size, it is a very rugged model. It once did fly to pieces, when after clumsy positioning on water, Seal dipped its lower wing, changed direction of the take-off run and charged the boat. In the next second, the model shot through two of the cabin windows, the impact smashing the rest of the glass too!

The construction of all these flying boats is all balsa, except the hardwood engine bearers, two main struts of pylons and wing-fastening dowels, ply being used for those wing ribs where the dowels seat. The hull is all planked with 1/16 in. balsa sheet, flying surfaces being covered with thin brown wrapping paper. This paper was used a lot in Finland during the war years, later rejected because of weight. However it is extremely tough and elastic, and after the final varnish it is completely water-proof. Full building instructions are included with each of the APS plans for Gull and Seal, but since they are different in their layout of thrustlines and drag centres, some trimming problems may arise and these will be of interest.

Glide trim is best obtained by ballasting rather than by altering tailplane incidences the usual way. The wing and tailplane settings on the plans are necessary for water take-offs, so in order to obtain a stall-free glide, add more ballast to the nose. Bore a hole in the solid nose piece and fill with solder. Do not be afraid of moving the c.g. forward of the location noted on plans, as that shown is the ultimate possible rearward position. To control the glide angle, move to a high bank-side spot to launch. The short glide resulting from a launch standing in a boat is not sufficient..."

The T11 Seal and the T10 Gull (oz3008) model plans appeared together in the same article, in Nov 1963 Aeromodeller.

Added a very clear (but sadly with no dimensions) version of this plan, courtesy of Modelholic.

Supplementary file notes

Alternate plan version.
Article.

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