Das Kleine Bipe (oz9453)

About this Plan

Das Kleine Bipe. Radio control sport model.

Quote: "A sporty little biplane with a 36in wingspan and WWI appearance, for 2.5 - 3.5 cc motors and small multi radio.

Designing a model on a blank sheet of paper, and then building the creation is a very rewarding, if time-consuming activity.

Fortunately, I am one of those who believe very much that not a small part of the enjoyment in our hobby lies in the design and construction of the model, indeed perhaps as much, if not more; than can be had on the actual flying field. I fear so many of those reaching for the RTF or Kwik-bilt models miss the very essence of our hobby - the satisfaction of creating from a two-dimensional drawing something of character and with the ability to move in three dimensions under the direction of its earthbound master.

In designing a model aircraft we are usually putting the cart before the horse. The full-size design team would commence with a specification; move X people at Y mph for Z pence per mile - and might then find themselves designing an aeroplane or missile depending upon where the mathematics led them! How unlike is the model designer who first determines how the final product will look, adjusts the mathematics to suit the size of his car boot, and then thinks of some reasons to justify the choice!

In the case of DKB, since my preference is for small models and the club flying field is sufficiently rough to discourage much detail on the model, this was kept fairly simple and I set out to build a WWI type bipe without actually modelling one particular type. There is quite a lot to be said for a 'full house' bipe that can be thrown in the car boot in one piece and still leave room for all the other paraphenalia that normally collects in that space! Those with a thirsty 61 motor using a pint of fuel a flight will also recognise the economy of a 2 oz tank with a 2.5 cc power plant.

DKB is essentially a sport model - that is to say it cannot be expected to perform the FAI Aerobatic schedule - on the other hand it will do all that a weekend flier might ask of it. I cannot say that DKB actually 'flew off the drawing board' since it did at first exhibit some vices, ground looping on take-off, being very sensitive in pitch, and having a severe 'barrelling' roll. What else might you expect of a WWI airplane! The pitch sensitivity was cured by reducing the elevator throw and moving forward the CG, at the same time this improved the ground looping tendency which I cleared completely by moving the undercarriage further aft nearer the CG. Increased differential on the ailerons reduced the tendency to barrel roll..."

Das Klein Bipe, RCM&E, June 1970.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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