Safety Recommendations A-06-24 through -26
The NTSB recommends the following to the FAA:
Require MD Helicopters, Inc. (MDHI), to conduct additional tests
to enable the full analysis of all critical load cases for
tension-torsion straps installed in the anti-torque fan of MDHI
model 500N series, 600N, and MD900 helicopters, including load
cases that create regions of transverse shear or compression in the
fiber-reinforced areas of the straps...