AD 64-16-02

64-16-02 BOEING: Amdt. 772 Part 507 Federal Register July 23, 1964. Applies to Models 707 and 720 Series Aircraft Listed in Boeing Service Bulletin No. 1798(R-1).

Compliance required as indicated.

Cracks have occurred in the nacelle strut upper support fitting. These cracks, if allowed to progress, can result in failure of the upper support fitting. To correct this condition, accomplish the following or an equivalent approved by Aircraft Engineering Division, FAA Western Region:

(a) Aircraft which have not already been inspected in accordance with the provisions of paragraph (c) within 300 hours' time in service prior to the effective date of this AD shall be so inspected in accordance with the following:

(1) All 707-100, 707-100B and 707-200 Series aircraft shall be inspected as specified in paragraph (c) as follows:

(i) Within 200 hours' time in service after the effective date of this AD for aircraft with 6,000 or more hours' time in service onthe effective date of this AD; and

(ii) Prior to the accumulation of 6,200 hours' time in service for aircraft with less than 6,000 hours' time in service on the effective date of this AD.

(2) All 707-300, 707-300B and 707-400 Series aircraft shall be inspected as specified in paragraph (c) as follows:

(i) Within 200 hours' time in service after the effective date of this AD for aircraft with 8,000 or more hours' time in service on the effective date of this AD; and

(ii) Prior to the accumulation of 8,200 hours' time in service for aircraft with less than 8,000 hours' time in service on the effective date of this AD.

(3) All 720 and 720B Series aircraft shall be inspected as specified in paragraph (c) as follows:

(i) Within 200 hours' time in service after the effective date of this AD for aircraft with 4,500 or more hours' time in service on the effective date of this AD; and

(ii) Prior to the accumulation of 4,700 hours' time in service for aircraft with less than 4,500 hours' time in service on the effective date of this AD.

(4) All 707 and 720 Series aircraft shall be reinspected at intervals not to exceed 600 hours' time in service following the inspections required in (a)(1), (2) and (3).

(b) Aircraft which have been inspected in accordance with the provisions of paragraph (c) within 300 hours' time in service prior to the effective date of this AD, shall be reinspected at intervals not to exceed 600 hours' time in service from the last inspection.

(c) Visually inspect all surfaces of the upper and lower flanges of the nacelle strut upper support fitting for lateral cracks emanating from each clip or bracket attach hole.

(d) If cracks are found during the inspections specified in paragraphs (a) and (b), replace the fitting with a new fitting of the same part number before further flight.

(e) Unless already accomplished, modify each inner and outer nacelle strut upper support fitting in accordance with the provisions of paragraph 3, "Modification Data" Section, Boeing Service Bulletins Nos. 1798(R-1) or 1798(R-2). Such modification shall be accomplished in accordance with the following schedule:

(1) All 707-100, 707-100B, and 707-200 Series aircraft:

(i) Within 6,000 hours' time in service after the effective date of this AD for aircraft with 6,000 or more hours' time in service on the effective date of this AD; and

(ii) Prior to the accumulation of 12,000 hours' time in service for aircraft with less than 6,000 hours' time in service on the effective date of this AD.

(2) All 707-300, 707-300B, 707-300C and 707-400 Series aircraft:

(i) Within 6,000 hours' time in service after the effective date of this AD for aircraft with 8,000 or more hours' time in service on the effective date of this AD; and

(ii) Prior to the accumulation of 14,000 hours' time in service for aircraft with less than 8,000 hours' time in service on the effective date of this AD.

(3) All 720 and 720B Series aircraft:

(i) Within 6,000 hours' time in service after the effective date of this AD for aircraft with 4,500 or more hours' time in service on the effective date of this AD; and

(ii) Prior to the accumulating of 10,500 hours' time in service for aircraft with less than 4,500 hours' time in service on the effective date of this AD.

(f) The inspections specified in paragraphs (a) and (b) are not required when the modifications specified in paragraph (e) are incorporated.

(g) 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 operator if the request contains substantiating data to justify the increase for such operator.

(Boeing Service Bulletins Nos. 1798(R-1) and 1798(R-2) cover this same subject.)

This directive effective July 23, 1964.

Revised January 16, 1965.