96-20-07: Combustion Heaters

96-20-07 JANAERO DEVICES (formerly Janitrol, C&D, FL Aerospace, and Midland-Ross Corporation): Amendment 39-9773; Docket No. 95-CE-83-AD; Supersedes AD 82-07-03, Amendment 39-4354, which superseded 80-09-10 amendment 39-3766. Applicability: B-Series combustion heaters, Models B1500, B2030, B3040, and B4050, marked as meeting the standards of TSO-C20, that do not incorporate a ceramic combustion tube and a part number (P/N) 94E42 combustion air pressure switch, and are installed on, but not limited to, the following aircraft (all serial numbers), certificated in any category: Manufacturer Models and Series Model Airplanes Beech Models 95-B55 Series, 58, 58TC, 58P, 60, A60, and 76. Canadair Models CL-215, CL-215T, and CLT-415. Cessna Models 208, 303, 310F, 310G, 310H, 310I, 310J, 310K, 310L, 310M, 310N, 310O, 310P, 320C, 320D, 320E, 320F, 337 series, 340 340A, 414, 414A, 421, 421A, 421B, and 421C. NOTE 1: B-Series combustion heaters, Models 2500,B3500, and B4500, incorporate a ceramic-coated combustion tube and new combustion air pressure switch, P/N 94E42. This AD does not apply to this configuration. NOTE 2: This AD applies to each aircraft identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required as follows, as applicable: - For aircraft with 450 or more heater hours time-in-service (TIS) (see NOTE 3 for information on how to determine heater hours TIS) accumulated on an installed heater since the last overhaul or new installation, within the next 50 heater hours TIS or 12 calendar months after the effective date of this AD, whichever occurs first, unless already accomplished, and thereafter at intervals not to exceed 100 heater hours TIS or 24 calendar months, whichever occurs first; - For aircraft with less than 450 heater hours TIS accumulated on an installed heater since the last overhaul or new installation, upon accumulating 500 heater hours TIS on the new or overhauled heater or within the next 12 calendar months after the effective date of this AD, whichever occurs first, unless already accomplished, and thereafter at intervals not to exceed 100 heater hours TIS or 24 calendar months, whichever occurs first; and - Upon installing one of the affected heaters, and thereafter at intervals not to exceed 100 heater hours TIS or24 calendar months, whichever occurs first. NOTE 3: A heater hour meter may be used to determine heater hours TIS. Also, aircraft hours TIS may be divided in half to come up with heater hours TIS. To prevent an airplane fire or explosion caused by failure of the heater combustion tube assembly or combustion air pressure switch, accomplish the following: (a) Test (pressure decay test) the combustion tube of the heater and conduct an operational test of the combustion air pressure switch in accordance with Section III, paragraph 3.3.1 through 3.3.13 (pressure decay test) and Section IV, paragraph 4.9c (operational switch test), of the Janitrol Maintenance and Overhaul Manual, part number (P/N) 24E25-1, dated October 1981. (1) If any heater does not pass any of the repetitive combustion tube pressure decay tests required by this AD, prior to further flight, overhaul the heater and replace the combustion tube with a serviceable tube or replace the heater assembly. If the new or rebuilt heater assembly incorporates a ceramic combustion tube, then the repetitive pressure decay tests are no longer required. (2) If any heater does not pass any of the repetitive combustion air pressure switch operational tests required by this AD, prior to further flight, replace the switch with one of the same design or with a P/N 94E42 switch in accordance with JanAero Devices Service Bulletin # A-103, dated September 1995. Replacing the combustion air pressure switch with a P/N 94E42 switch eliminates the repetitive operational testing requirement of this AD. (b) As an alternative method of compliance to the requirements of this AD, the heater may be disabled by accomplishing the following: (1) Cap the fuel supply line; (2) Disconnect the electrical power and ensure that the connections are properly secured to reduce the possibility of electrical spark or structural damage; (3) Inspect and test to ensure that the cabin heater system isdisabled; (4) Ensure that no other aircraft system is affected by this action; (5) Ensure there are no fuel leaks; and (6) Fabricate a placard with the words: "System Inoperative". Install this placard at the heater control valve within the pilot's clear view. (c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. (d) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Atlanta Aircraft Certification Office (ACO), Campus Building, 1701 Columbia Avenue, suite 2-160, College Park, Georgia 30337-2748. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO. Alternative methods of compliance for the combustion tube repetitive inspections required by this AD that are approved in accordance with AD 82-07-03 (superseded by this action) are approved as alternative methods of compliance with the applicable portion of paragraph (a) of this AD. NOTE 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO. (e) The possible switch replacement required by this AD shall be done in accordance with JanAero Devices Service Bulletin # A-103, dated September 1995. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from JanAero Devices, Airport Complex, P.O. Box 273, Fort Deposit, Alabama 36032. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (f) This amendment (39-9773) supersedes AD 82-07-03, Amendment 39-4354. (g) This amendment becomes effective on November 14, 1996.