Progress within the possibilities
In 1977 it received an increased engine volume to 3.6 liters, which means that the Avia reached lower revs with the same power. This achieved greater durability and at the same time reduced the amount of emissions, which were still hellish. The original Avia A15 received the A20 designation in 1979 increasing the carrying capacity and since 1983 it has even become A21. In the 1980s, five-speed gearboxes arrived, which were no longer controlled by a lever under the steering wheel. But all of this was desperately short for a model’s 30 years of production, so it’s no surprise that installing a turbo, which increased power from the original 63 kW to a decent 76 kW in the 1990s, didn’t help. The smaller A21 was able to reach over 110 km / h in this way.
Be that as it may, until the fall of socialism, the production of airplanes was not enough to cover the demand, but after the Velvet Revolution, the situation quickly changed to the other extreme: suddenly almost nobody wanted airplanes. Even so, production continued for the next eight years.