It is one of the most fiddly, fragile and hardest kits i have ever built. Nearly every part broke trying to get it off the sprue, and the thing is so lopsided and difficult to handle without breaking even more bits, a few swear words were used during construction

A bit of history

During the final months of W.W.1 , the Austro-Hungarian Army's Major Stephan Petrochy assisted by Theodore von Karman and Vilem Zurovec, designed a radical motorized flying machine to replace the dangerous hydrogen-filled balloons then being used to observe enemy positions. Their odd, triangular contraption with counter-rotating propellers ultimately made 30 successful tethered test flights before the project was cancelled. Although never operational, the PKZ-2 was, in fact, the world's first true helicopter, and the only helicopter to fly during W.W.1.
Andy

And just to see how small this thing is, standard Tamiya and Revell paint tins
