AD 65-09-01

65-09-01 BOEING: Amdt. 39-61 Part 39 Federal Register April 29, 1965. Applies to Model 707 Series Aircraft, Serial Numbers 17592 through 17608, 17614 through 17627, 17673 through 17690, 17692 through 17695, 17918 through 17924, 17928 through 17930, 18083 through 18085, 18245, 18246, 18374, 18375 and 18460.

Compliance required as indicated.

There have been failures of a rear engine mount nut attributed to embrittlement resulting from the nut being subject to temperatures which caused the cadmium to melt. To correct this condition, accomplish the following or an equivalent approved by the Aircraft Engineering Division, FAA Western Region.

(a) On all aircraft which have cadmium plated rear engine mount cone bolt nut and washer, visually inspect the engine mount cone bolt nut for cracks or evidence of melted cadmium within 300 hours' time in service after the effective date of this AD and thereafter at periods not to exceed 300 hours' time in service.

(b) If a crack, or evidence of melted cadmium is found, replace the cadmium plated nut and washer with a silver plated nut and washer, before further flight, in accordance with the provisions of paragraph 3 of Boeing Service Bulletin No. 1874 or later FAA-approved revision, or an equivalent nut and washer approved by the Aircraft Engineering Division, FAA Western Region. If the installation of the silver plated nut and washer is made in accordance with Service Bulletin No. 1874, visually check the installation for insufficient bolt thread exposure beyond the end of the nut as defined in paragraph I of Boeing Service Bulletin No. 1874A or later FAA- approved revision. If there is insufficient thread exposure, replace with new silver plated nut and washer in accordance with paragraph 2 of Service Bulletin No. 1874A or later FAA-approved revision.

(c) Within 1,000 hours' time in service after the effective date of this AD, replace cadmium plated nut and washer with silver plated nut and washerin accordance with the provisions of (b).

(d) Unless already accomplished, on all aircraft that have complied with Service Bulletin No. 1874 prior to the effective date of this AD, visually inspect the silver plated rear mount cone bolt and nut for insufficient bolt thread exposure beyond the end of the nut as defined in paragraph 1 of Boeing Service Bulletin No. 1874A or later FAA-approved revision within 300 hours' time in service after the effective date of this AD. If there is insufficient bolt thread exposure beyond the end of the nut, replace with new nut and washer in accordance with paragraph 2 of Service Bulletin No. 1874A or later FAA-approved revision before further flight.

(e) Upon request of the operator, an FAA maintenance inspector subject to prior approval of the chief, Aircraft Engineering Division, FAA Western Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operatorif the request contains substantiating data to justify the increase for such operator.

This directive effective May 29, 1965.