It's interesting to read these comments about poor higher-altitude (well, not too high actually) performance of the Turbolet.
We skydivers were absolutely amazed at its performance in comparison to what we were used to. I know you are probably starting to laugh when I compare it to a Cessna, but 8 minutes to 12,000 feet with 18 POB and minimal fuel was just out of this world. Our old C206 would run out of puff by about 9,000 feet and be doing about 300fpm if we were lucky. The Turbolet was regarded as a real high-performance aircraft. Oh well.
There were photographs in a skydiving magazine some years ago of an L410 which, after the jumpers exited, was pretty much keeping up with them in freefall on the way down in a near-vertical attitude (10,000 fpm descent). I wonder how close to the airframe limits they were !
By the way, a visitor to the drop zone one day who saw us going up to 13,000 feet asked if the aircraft was pressurised..........