SPECIAL AIRWORTHINESS INFORMATION BULLETIN

Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration

CE-10-49 R1

January 5, 2011

This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) is to inform registered owners, operators, and maintenance personnel of an airworthiness concern regarding heated drain masts (P/N 105881) on several Cessna Citation airplanes.

The recommendation included in this SAIB should be considered for all serial numbers for the following Cessna Citation airplanes:

Cessna Model	Citation
510	Mustang
525	CJ, CJ1, CJ1+
525A	CJ2, CJ2+
525B	CJ3
525C	CJ4
550	II, Bravo
560	V, Ultra, Encore, Encore+
650	III, VI, VII
750	X

At this time, the airworthiness concern is not an unsafe condition that would warrant Airworthiness Directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

This SAIB revises SAIB CE-10-49, dated September 23, 2010 for the following reasons:

• Recommendation section – updated to clarify the intent of the SAIB
• Related Service Information Contact section – updated to correct phone number
  

Background

During troubleshooting of an unrelated discrepancy on a Cessna Model 750 airplane, maintenance personnel smelled a burning odor. Upon further inspection, maintenance personnel found the heated galley drain mast (P/N 105881) self sustaining a fire. The fire was extinguished. Maintenance found the fiberglass heating element had overheated and caught fire. Maintenance personnel replaced the heating element and drain mast.

The national Service Difficulty Reporting System lists four failures of part number (105881) heated drain on three different model aircraft (including the one mentioned above). Three of the failures occurred during ground operation, of which two reported a visible fire and one reported a “discolored fillet fairing”. One of the failures was a new part that failed upon installation.

To address the issue of the drain heaters overheating while being powered on the ground, Cessna will be revising the maintenance manuals for the above-mentioned Cessna airplanes to add procedures for “Safe Ground Maintenance”, which will include procedures for disengaging power to the drain heaters. It is expected that the revision of the maintenance manuals will begin release in Quarter 3 of Year 2010.

Recommendations

The FAA recommends that owners, operators, and maintenance personnel disengage the power source to the heaters with the above-mentioned part number when the aircraft is on the ground and not released for flight. An example of a time it may be appropriate to remove the power to the heaters would be, but is not limited to, when the aircraft is powered in a hangar for routine or extended maintenance. Disengaging the power source in these situations will ensure longer reliability and avoid failures of the heaters. Until the maintenance manuals revisions are released, you may contact Cessna Aircraft Company for any specific questions regarding the procedures for disengaging the power to the heaters on your specific model.

For Further Information Contact

Christine Abraham, Aerospace Engineer, 1801 Airport Road – Room 100, Wichita, KS 67209; phone: (316) 946-4165; fax: (316) 946-4107; e-mail: christine.abraham@faa.gov.

For Related Service Information Contact

Cessna Aircraft Company, One Cessna Boulevard, P.O. Box 7704, Wichita, KS 67277; phone: (316) 517-6261.