AD 90-09-10 ACTIVE

90-09-10 TEXAS INSTRUMENTS: Amendment 39-6565. Docket No. 89-ANE-38.

Applicability: To circuit breaker Models 6TC6-7.5 and -10 and 6TC20-7.5 and -10, all with date codes 8150 and earlier.

Compliance is required no later than November 1, 1990, unless already accomplished.

(a) To prevent potential overheating of the applicable circuit breakers, replace Texas Instruments circuit breaker Models 6TC6-7.5 and -10 and Models 6TC20-7.5 and -10, all with date codes 8150 and earlier. These circuit breakers may be replaced with the same model numbers with the manufacturing date codes of 8151 and later.

NOTE: The circuit breakers are installed in, but not limited to, aircraft manufactured by Boeing Commercial Airplanes and Lockheed Corporation. Service bulletins published to date, which may be helpful in identifying replacement circuit breakers, are as follows:

(1) The Boeing Commercial Airplanes' service bulletins 757-24-0054, 747-24-2135, and 767-24-0060, all dated August 31, 1989. Their part numbers BACC18AC7 and BACC18AC10 are used to identify Texas Instruments Model 6TC6-7.5 and 6TC6-10, respectively.

(2) The Lockheed Corporation service bulletin 093-24-134, dated August 12, 1987. Their part numbers LS10159-7 and LS10159-10 are used to identify Texas Instruments Model 6TC20-7.5 and 6TC20-10, respectively.

(b) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance times specified in this AD may be approved by the Manager, Boston Aircraft Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803.

This amendment (39-6565, AD 90-09-10) becomes effective on May 30, 1990.