AD 93-24-15 Instrument Panel Rheostat
February 11, 1994
This AD applies to 150F-J, and F150F-J.
To prevent inflight fire caused by a short in the wiring controlled by the instrument panel lighting rheostat, the rheostat in the affected aircraft must be replaced with one of improved design that is current limited and heat protected.
93-24-15 CESSNA AIRCRAFT COMPANY: Amendment 39-8764. Docket No. 93-CE-43-AD. Applicability: The following model and serial number airplanes, certificated in any category:
| Models | Serial Numbers |
| 150F, 150G, 150H, and 150J. | 15061533 through 15071128. |
| F150F, F150G, F150H, and F150J. | F150-0001 through F150-0529. |
| 172E, 172F, 172G, 172H, 172I, and 172K (T-41A). | 17250573 through 17259223. |
| F172E, F172F, F172G, and F172H. | F172-0019 through F17200754. |
| FR172E, FR172F, and FR172G. | FR17200001 through FR17200225. |
| 180H and 180J. | 18051446 through 18052384. |
| 185D, 185E, and 185F. | 185-0777 through 18502310. |
| R172E, R172F, R172G, and R172H (T-41B, T-41C, and T-41D). | R172-0001 through R172-0452. |
Compliance: Required within the next 6 calendar months after the effective date of this AD, unless already accomplished.
To prevent an in-flight fire caused by a short in the electrical wiring controlled by the instrument panel light dimming rheostat, accomplish the following:
(a) Replace the existing instrument panel light dimming rheostat with one of improved design that is current-limited and heat-protected, part number RD-0015H-1600, in accordance with Cessna ACCOMPLISHMENT INSTRUCTIONS SEB92-33R1, Revision 1, dated June 25, 1993.
(b) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.
(c) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Wichita Aircraft Certification Office.
NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita Aircraft Certification Office.
(d) The replacement required by this AD shall be done in accordance with Cessna ACCOMPLISHMENT INSTRUCTIONS SEB92-33R1, Revision 1, dated June 25, 1993. 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 Cessna Aircraft Company, P.O. Box 7704, Wichita, Kansas 67277. 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.
(e) This amendment becomes effective on February 11, 1994.