Several blade retention samples made of improved wood were tested in various technical research centers with impressive results:
Example:
A 60. mm diameter sample of the blade root of the GT design for Rotax engines:
912 ,912-S, 914, 80/130 hp with max propeller rotation of 2700 rpm,
showed an average tear test load result of 22.000 KGf
Please note:
The GT blades mentioned above weight about 1.5 to 1.8 kg,s each.
At this weight the root load forces at max engine rpm of 2550, standard of rotax 912/914 family, is 2.700 kgf per blade.
The application safety factor of GT blades roots result is that the GT blades for Rotax applications are 7 times stronger than required by Rotax engine operating at full power in service.
