98-14-03 ALLIEDSIGNAL INC.: Amendment 39-10637; Docket No. 97-CE-30-AD.

Applicability: AlliedSignal KT 76A Air Traffic Control (ATC) transponders; part number (P/N) 066-1062-00/10/02; serial numbers 93,000 through 109,999, as installed on, but not limited to the following airplanes (all serial numbers), certificated in any category:

• Cessna Aircraft Company: 172, 182, R182, T182, 206, P206, U206, TP206, 210, T210, P210, 310, E310, T310, and 421 series airplanes.

• Twin Commander Aircraft Company: 500, 520, 560, 680, 681, 685, 690, 695, and 720 series airplanes.

• The New Piper Aircraft Corporation: PA-31, PA-32, and PA-34 series airplanes.

• Raytheon Aircraft Company: E33, F33, G33, 35, J35, K35, L35, K35, M35, P35, S35, V35, 36, A26, B36, D55, E55, 56, A56, 58, 58A, 95, B95, D95, and E95 series airplanes.

• Mooney Aircraft Corporation: M20 series airplanes.

• McDonnell Douglas Helicopter Company: Model 500N rotorcraft.

NOTE 1: This AD applies to each aircraft equipped with a transponder that is 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 aircraft 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 within the next 12 calendar months after the effective date of this AD, unless already accomplished.

To prevent the transmission of misleading encoding altimeter information between affected aircraft caused by the inability of the affected ATC transponders to coordinate with ground-based air traffic control (ATC) radar sites and nearby Traffic Alert and Collision Avoidance System (TCAS)-equipped aircraft, accomplish the following:

(a) Replace the two resistor network modules, RM401 and RM402, with new glass-coated parts in accordance with the MODIFICATION PROCEDURE section of AlliedSignal Service Bulletin SB KT 76A-7, dated July 1996. When accomplished, this replacement is referred to as Mod 7.

(b) As of the effective date of this AD, no person may install an AlliedSignal KT 76A ATC transponder; part number (P/N) 066-1062-00/10/02; serial numbers 93,000 through 109,999, in an aircraft without first incorporating Mod 7 as specified in paragraph (a) of this AD.

(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, Wichita Aircraft Certification Office (ACO), 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 ACO.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO.

(e) The replacement required by this AD shall be done in accordance with AlliedSignal Service Bulletin SB KT 76A-7, dated July 1996. 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 AlliedSignal Inc., General Aviation Avionics, 400 N. Rogers Road, Olathe, Kansas 66062-1212. Copies may be inspected at the FAA, Central Region, Office of the Regional 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 becomes effective on August 16, 1998.

FOR FURTHER INFORMATION CONTACT: Mr. Roger A. Souter, Aerospace Engineer, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Mid-Continent Airport, Wichita, Kansas 67209; telephone: (316) 946-4134; facsimile: (316) 946-4407.