AD NUMBER: 2004-23-15
MANUFACTURER: MDHI (CORRECTION) SUBJECT: Airworthiness Directive 2004-23-15 SUMMARY: This amendment adopts a new airworthiness
directive (AD) for the MD Helicopters, Inc. (MDHI) Model MD900
helicopters. This action requires reducing the life limit of
certain Notar fan system tension-torsion (TT) straps. This action
also requires, at a specified time interval, removing each affected
TT strap from the helicopter, doing a visual and x-ray inspection,
and replacing any unairworthy part before further flight. Reporting
the discovery of any unairworthy TT strap is also required. This
amendment is prompted by two recent in-flight TT strap failures.
The actions specified in this AD are intended to prevent failure of
a TT strap resulting in loss of directional control and subsequent
loss of control of the helicopter.