SAIB CE-04-04

SPECIAL

AIRWORTHINESS

INFORMATION

BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

No. CE-04-04 October 16, 2003 www.faa.gov - Search "SAIBs" This is information only. Recommendations are not mandatory.

Introduction This Special Airworthiness Information Bulletin (SAIB) alerts you, owner or operator of Raytheon Aircraft Company (formerly Beech Aircraft) models noted below, that may be equipped with Janitrol Model S-50 combustion heater, of the potential of thermal distress on the combustion head of these heaters.

Twin Bonanza Model Serial Numbers B50 All C50 All D50 All D50A All D50B All D50C All E50 All F50 All G50 All H50 All J50 All Baron Model Serial Numbers 55 All A55 All B55 TE-339 thru TE-942 and TC-1608 thru TC1657 E55 TE-938, TE-943 thru TE-958 and TE-960 thru TE-967 58 TH-1 thru TH-436 56TC TG-1 thru TG-83 A56TC TG-84 thru TG-94 Travel Air Model Serial Numbers 95 All B95 All B95A All D95A All E95 All

2 Background One Repair Station has reported thermal erosion at the 9:30 location on combustion head of three Model S-50 combustion heaters. All 3 combustion heads demonstrated nearly identical erosion patterns. Records indicate that the aircraft/combustion heater manufacturer’s recommended maintenance procedures may not have been followed. This apparent lack of maintenance is compounded in that many of these heaters have been in service since the early 1960s.

Maintenance instructions for the Model S-50 combustion heater (Part Numbers C83A28, D83A28, E83A28 and F83A28) are provided in Janitrol Heater Instruction Part Number 30C57. This maintenance instruction specifies a visual inspection of all fuel and air fittings and the verification of the security of ignition leads and ignition unit at 100-hour intervals of heater operation. If a heater hour meter is not installed or is not functional, it is typical to assume that there is one hour of heater operation for each two hours of aircraft time in service. As there are both fuel and ignition connections on the combustion head, the recommended inspections are in the vicinity of the noted thermal distress. The combustion heater maintenance instruction also recommends overhauling the heater at 500 heater operating hour intervals, or at each engine overhaul, whichever occurs first.

Recommendation After reviewing available data, we recommend that you, the owner or operator, be aware that distress has been noted on the combustion head of the Model S-50 combustion heater that should be detectable during maintenance actions specified in the manufacturer’s instructions. We recommend that you comply with the maintenance actions and intervals specified in Janitrol Heater Instruction Part Number 30C57.

Note: Based on current information we, the FAA, only recommend these actions. We will continue this investigation and analyze any added information. We may require additional actions, such as the issuance of an Airworthiness Directive based on this analysis.

For Other Information Contact Kevin Brane, Aerospace Engineer, FAA, Central Region, Atlanta ACO, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, GA 30349; phone (770)-703-6063; fax (770) 703-6097;

email: kevin.brane@faa.gov.

Kelly Aerospace Power Systems, Airport Complex, P.O. Box 273, Fort Deposit, AL 36032; phone:

(334) 227-8306 for copies of the instruction manual.