The bulletin
Text extracted from the PDF.
REVISED SPECIAL AIRWORTHINESS
INFORMATION BULLETIN
Aircraft Certification Service Washington, DC
U.S. Department of Transportation Federal Aviation Administration
SW-06-20R1 May, 5, 2006 http://www.faa.gov/aircraft/safety/alerts/ This is information only. Recommendations aren’t mandatory
Introduction
This Special Airworthiness Information Bulletin (SAIB) alerts you, owners and operators of certain, Meggitt/S-TEC Corporation pitch servo components, listed below, that could exhibit a potential failure of the pitch servo causing autotrim operation to become inoperative or unreliable. The pitch servo is installed in various small airplanes that have a Meggitt/S-TEC autopilot configuration.
Failure indications could include loss of pitch servo operation, loss of or faulty autotrim operation, or loss of or faulty trim requirement indications. The loss of autotrim capabilities could result in an "out of trim" condition at autopilot disconnect.
SERVO COMPONENTS Servo Part Number and Type Serial Number Range/Manufacture Dates 0107-( )-( ) and 14 VDC 0505-15886 to 0519-16166 / Feb. 2, 2005 to May 10, 2005 0108-( )-( ) and 28 VDC 0505-14131 to 0519-14543 / Feb. 2, 2005 to May 11, 2005 01230-( )-( ) and 28 VDC 0452-076 to 0517-090 / Dec.
20, 2004 to Apr. 29, 2005
Background
We received notification from Meggitt/S-TEC Corporation, the servo manufacture, that they have identified two servos in their production line with trim switch actuation arm fastener lose. In one case, the fastener was loose within the servo housing. The second case noted pitch autotrim was inoperable during initial installation ground checks. They discovered both defects prior to the production phase of certification.
Recommendation
To prevent additional failures of the pitch servos, we strongly recommend that you comply with Meggitt/S-TEC Service Bulletin 05-004 (attached).
For Further Information Contact
Gary Middleton, Aerospace Engineer, FAA Rotorcraft Directorate, ASW-111, 2601 Meacham Blvd., Forth Worth, TX 76137;
phone: (817) 222-5197; fax: (817) 222-5960;
email: gary.middleton@faa.gov