For new members of the club or anyone not into thermal soaring, this is the glider used by John to win the annual Rose Bowl competition on numerous occasions. It follows the lines of Graupner's Cirrus, first produced in 1969, with wings and tailplane of built-up construction.
John's fuselage is made from large chunks of balsa with ply in strategic places, all nicely carved, and is surprisingly light. He has extended the nose to minimise the amount of lead needed to balance it. The wings are attached by rubber bands over dowels.
The only cunning feature of this model is in the wing centre section where he has built in a retractable extra trailing edge which, when operated by a single standard servo in the centre of the wing, extends the trailing edge by 30mm, and more or less follows the curvature of the upper surface. Although John incorporated this feature on his second Cirrel, he says it is not really successful and does not use it.
The only addition to his second Cirrel is letterbox type spoilers built into the centre section. Neither model has ailerons fitted. The wing section is the type popular in the '70s with a flat lower surface and very little radius at the leading edge. Not a man to baffle you with jargon and technicalities, he does admit to having a change in section on the outer panels where the tips are almost symmetrical, giving some aerodynamic washout, plus approximately 6mm built-in washout at the trailing edge.
The wings are of
standard construction, with sheeted leading edges and are very
light, even down to the wing joiners which are 1/16in aluminium
sheet bonded to 1/16in ply with a depth of 15mm. The total weight
of the model inspected was 1380g without any radio or electrics.
The key dimensions are given on the photographs in millimeters.
This is a big model which can be flown at some distance and the long moment arms must help with stability. It is very light and I would be hesitant to put it up with a strong bungee, but notice the forward two hook position (445mm back from the nose) and at last year's Rose Bowl competition John managed to consistently get good launch height. It is a tribute to John's construction and flying that there are no signs of damage or repairs.
This type of glider does not require megabucks to build or fly and in the hands of an exceptional pilot like John is unbeatable in normal flying conditions. At the same time it could provide hours of pleasant flying for the less experienced. On the other hand, if you are not short of a penny or two and need a regular dose of adrenaline, then get yourself a glass ship. I am sure Dave or Neil can help you. (See South Coast Sailplanes on the links page of the C&DMFC Website - Ed)
Thanks to John or entrusting me with Cirrel number one - but I am still left with a sneaking suspicion that there is something magic about Cirrel number two that is not being disclosed! (That would be the Helium bags in the wings, maybe? - Ed)