The newly-developed epoxy carbon fiber matrix can tolerate increased damage to the leading edge of the fan thereby dramatically improving resistance to damage caused by bird ingestion. “This advancement was inadvertently validated when a screwdriver was accidentally ingested into a fan during the maximum power tests of an M400,” stated Dr. Paul Moller, President of Moller International. “The screwdriver caused a significant notch in the leading edge of the fan but was quickly repaired with epoxy filler. An aluminum fan blade would have to be replaced if it had survived the impact, which is problematic.”
Carbon fiber has up to seven times the tensile strength of aluminum. As a result, the blades can be designed to have a very large safety factor.