Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
NM-07-48
September 11, 2007
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin advises you, owners
and operators of Gulfstream Model G-IV series airplanes, serial numbers
1000 through 1278, that Gulfstream has identified an issue concerning a
potentially reduced lug radius dimension on the aileron boost bellcrank
clevis.
Background
Gulfstream discovered that the lug radius dimension of the aileron
boost bellcrank clevis had been manufactured incorrectly. The hydraulic
actuator attaches to the suspect lug. Failure of the bellcrank lug
results in loss of hydraulic power to that aileron surface. Control of
the aileron is maintained through manual reversion.
Recommendations
Gulfstream has issued GIV Customer Bulletin (CB) 121 to recommend a
one-time action to inspect the aileron boost bellcrank lug thickness to
lug radius ratio. The lug inspection measures the lug thickness and lug
radius using a vernier caliper. We strongly recommend that you
accomplish the actions suggested by and detailed in Gulfstream GIV CB
121.
For Further Information Contact
Gerald Avella, Aerospace Engineer
FAA Atlanta Aircraft Certification Office
One Crown Center, 1895 Phoenix Boulevard, Suite 450
Atlanta, GA 30349
Phone: (770) 703-6066; Fax: (770) 703-6097
E-mail: Gerald.Avella@FAA.gov