Heinkel glider with PLEXIGLAS® canopy

© Evonik Industries AG, Konzernarchiv Hanau

A milestone in aviation history

Flying higher, faster and safer – this is only possible when using the right materials, such as PLEXIGLAS®. The material was used as early as the 1930s for producing curved canopies for aircraft.

Thanks to the use of this then-novel material by Röhm & Haas, now known as Röhm, the development of aircraft construction really took off. While pilots previously sat in an open cabin, only protected by a small windshield, the use of PLEXIGLAS® made it possible to construct curved canopies – and this was also necessary in order to increase speeds and fly at higher altitudes, as this involves greater air resistance, lower temperatures and declining air pressures.

A resilient material

Originally, PLEXIGLAS® was used in aircraft construction because it only weighed half as much as the previously used silicate glass. But the material was also much more durable and stronger. Soon it became clear that PLEXIGLAS® had even more to offer. The material is weather-resistant and highly durable – properties that are of utmost importance at altitudes of up to 15,000 meters, where materials must be capable of withstanding enormous mechanical and thermal stresses. What is more, PLEXIGLAS® can be milled, sawed and polished and is easy to shape – ideal features for aircraft construction.

Top speeds thanks to PLEXIGLAS®

Soon after its invention, aircraft manufacturers sought to make use of this versatile new material. One of the first applications was the closed PLEXIGLAS® glazing of Heinkel’s He 70. The streamlined canopy made it possible to reduce air resistance and thus increase speed. The Heinkel He 70 was thus the world’s fastest commercial aircraft of its day, reaching top speeds of up to 362 km/h.

Heinkel He 70 aircraft with PLEXIGLAS® canopy

Ahead of its time

The Heinkel He 70 set several speed records, which gave rise to its nickname “Blitz”. The aircraft was able to carry five passengers and one pilot. The Heinkel He 70 was also equipped with the world’s first retractable landing gear, resulting in even better aerodynamics.

© Evonik Industries AG, Konzernarchiv Hanau

An indispensable material

Thanks to its properties, PLEXIGLAS® quickly rose to become a truly indispensable material for the ever-growing aviation industry. Even today, Röhm’s brand acrylic glass continues to be an important material in aircraft construction and is used, for example, in cabin windows of passenger airplanes and as a windshield and canopy for gliders and sports aircraft.