Image copyright by Kow Yokoyama. The PK50 Hummel was an experimental aircraft built upon the chassis of the PK40 Fledermaus. It is a large aircraft - larger than the PK41, but is more heavily armoured by having an all enclosed cockpit. This was made possible by the experimental indirect sighting system that was installed. The aircraft was heavy, and as a result, slower than liked, and in addition, there were some initial concerns about whether the landing gear would support the weight of the aircraft. Weaponry was supplied by a high-powered laser (the same as used on the PKA Gustav) and by being able to mount bombs behind the cockpit. Ultimately not many of these aircraft were built, it remaining in the experimental classification.