Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
SW-07-17
February 16, 2007
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) alerts
owners, and operators of MD Helicopters Inc. (MDHI) model 600N
helicopters that the lateral mixer output link assembly (mixer link),
part number 600N7636, may develop cracks which radiate from the bearing
bores on the link ends. MDHI has issued a service bulletin to perform
inspections of the mixer link . The service bulletin is available on
the company web site at www.mdhelicopters.com. This SAIB applies to all
MDHI model 600N Helicopters.
Background
One mixer link, P/N 600N7636-1, from an in service model 600N
helicopter was found to have a crack through the bearing end area of
the link. Two additional 600N7636 mixer link parts from spares have
been reported with cracks in the bearing end area. Inspections of the
mixer link should be performed as soon as possible.
Recommendations
As soon as possible remove mixer links, part numbers 600N7636-1,-3,
and do visual and eddy current inspections of the bearing end areas
(See MDHI Service Bulletin SB600N-044, dated 16, February 16, 2007). If
any cracks are detected in the mixer links, replace with airworthy
parts before further flight.
For Further Information, Contact
Jon Mowery, Aerospace Engineer, Los Angeles Aircraft Certification Office, ANM-120L
3960 Paramount Blvd, Lakewood CA 90712
Telephone (562) 627-5322, fax: (562) 627-5210
Email: jon.mowery@faa.gov