Pushair (oz15264)

About this Plan

Pushair. Free flight rubber sport model, with pusher layout. Wingspan 15-1/2 in.

Quote: "Your full size free plan. A 15-1/2 in wingspan rubber powered free-flight pusher layout model specially developed for Meccano Magazine readers. Pushair, by Ray Malmstrom.

Follow the step by step photo building instructions for the correct building sequence. Flying notes and more photos on page overleaf.

THERE ARE a lot of aeromodellers who think that which are different, out-of-the-rut, or unusual (pushers, canards, deltas, etc), are more difficult to trim and fly than the run-of-the-mill, 'wing on top, prop at the front' type. This attitude, besides being quite untrue, results in the hobby being far less exciting, imaginative and forward-looking than it could be. In aeromodelling, as in so many other worthwhile activities, variety is (or should be) the very spice of life.

If you are one of those who like a little spice in your aeromodelling, spend a few hours on this little job. Pushair, built and powered according to the plan, should need no flight trimming at all to obtain a satisfactory flight. Even our conventionally minded brothers cannot do better than that! The full-size plan and photo-stages will give you all the information you need. The usual advice, of course, applies: build accurately, avoid warps and balance carefully.

Flying notes: As always, choose a calm day and soft grass for first tests (though with a pusher you are hardly ever likely to break a propeller!). With motor unwound, launches from shoulder height (a gentle push forward; avoid any tendency to throw the model) should produce a straight glide of up to 25 ft before touch-down. Satisfactory? Good. Now wind on about 250 turns (80 turns approximately on a 3: I geared winder). Remember to wind the propeller in an anti-clockwise direction - you have a pusher on your hands! A gentle climb, a short cruise and a good glide should result.

If all has gone well - and it should - you can steadily step up the turns, on well-lubricated rubber, to 850 (the rubber will take it!). Here, incidentally, a tip. When the motor has been wound by a winder, add 50-75 turns by hand before launching. The hand turns give you that extra 'zip' for a good climb. OK? Duration? Well, on a 16 in loop of 1/8 strip, it isn't in the Wakefield Contest class, that's for sure. Flights of 25 seconds are common, rock-steady with three-pointer landings when the surface is smooth. Our best flight to date is 32 seconds. You can probably beat this - it shouldn't be difficult. As a bonus, Pushair flies very well round-the-pole indoors - something new for those indoor winter club meets.

Finally, a couple of suggestions for the adventurous. Why not scale up Pushair by half to 24 in span? (Fit a 6 inch diameter propeller, preferably a wide-blade, free-wheeling job). Performance should be most rewarding. Secondly, if you really want to go places, how about beefing construction a little (keeping span to 24 in), and fitting the great little Cox .010 engine - it will run backwards quite easily. Well, it's an idea! Put a little spice in your aeromodelling!"

Direct submission to Outerzone.

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