FES Propeller Manual Version 1.23
October 2022
Page 6 of 11
4. Construction
4.1 Certification standards
Propeller type FES DG P1 102 described here is designed and tested according to
CS 22 Subpart J.
This manual is intended to comply with CS
‐
22.1903, providing the essential
information for installing, servicing, and maintaining the propeller.
4.2 Construction Material
Propeller blades are made of CRFP (carbon fiber reinforced plastic). They are
produced in accurate metal molds, which were manufactured using modern CNC
technology. This made it possible, to have very accurate profile geometry. At attachment
point of propeller blade is integrated hardened steel bushing with very accurate tolerance,
so that play is minimal.
Propeller hub is CNC milled part, from Aluminum alloy 7075,
black anodized.
4.3 Surface finish
High quality acrylic white paint (PPG D700) is used to protect the composite body
against moisture and erosion. Each blade pair is sanded and polished so that mass
difference is only about 0,1g (0,3g is maximum weigh difference tolerance). Paint is
resistant against fuel, oil and other chemical products. This type of paint has also an
excellent flexibility. Only tips of the propeller blades can be painted in other colors as a
safety mark. Otherwise only allowed color is white as this is structural part.
