AD 79-15-04

79-15-04 MCDONNELL DOUGLAS: Amendment 39-3514 as amended by Amendment 39-3565. Applies to Model DC-10-10, -10F, -30, -30F, and -40 airplanes certificated in all categories.

Compliance required as indicated.

To ensure the integrity and condition of the wing leading edge slat mechanical drive system, accomplish the following:

(a) Before further flight, after the effective date of this AD, unless already accomplished after June 6, 1979, and thereafter at intervals not to exceed 325 landings since the last inspection.

1. Visually inspect all slat system drive cables and pulleys in situ for security, and general condition (corrosion, damage, etc.);

2. Visually inspect all slat system followup cables and pulleys in situ for security and general condition (corrosion, damage, etc.);

3. Visually inspect the inboard and outboard slat drive mechanisms while operating the slat system to verify security of the components and freedom of movement of the mechanisms;

4. Correct all discrepancies found during the above inspections which exceed the condition limitations provided by the McDonnell Douglas DC-10 Maintenance Manual; and

5. Report results of all inspections to the Chief, Aircraft Engineering Division, FAA Western Region within 24 hours of accomplishment in the following format:

(1) "N" Number

(2) Total landings at inspection

(3) Results of inspection by specific paragraph and subparagraph of this AD

(4) Part Number

(5) Identify contact for follow-up

(b) For #2 and #3 position, slat drive cables, except "zinc coated 6 x 31 or 7 flex premium cables," before accumulating an additional 810 landings on any individual cable, after the effective date of this AD, unless a new cable was installed within the last 5,700 landings, and thereafter at intervals not to exceed 6,500 total landings on any individual cable, replace the affected drive cable with a new cable of the same part number or anFAA approved replacement cable. If a cable is replaced with a "zinc coated 6 x 31 or 7 flex premium cable," the cable replacement limits specified in paragraph (c) become effective for the replacement cable.

(c) For #2 and #3 position, slat "zinc coated 6 x 31 or 7 flex premium" type drive cables, before accumulating an additional 810 landings on any individual cable after the effective date of this AD, unless a new cable was installed within the last 10,000 landings, and thereafter at intervals not to exceed 10,800 total landings on any individual cable, replace the affected drive cable with a new cable of the same part number or an FAA approved replacement part.

(d) Part numbers of "zinc coated 6 x 31 or 7 flex premium cables" which are approved replacement cables for compliance with either paragraphs (b) or (c) are identified by McDonnell Douglas All Operators Letters, (AOL), 10-1333A dated October 26, 1978 and 10-1379 dated January 8, 1979.

(e) The repetitive inspections required by paragraph (a) may be discontinued after the inspections and modifications required by paragraph (b) of AD 78-20-04 (Amendment 39-3308) have been accomplished and after it has been determined that #2 and #3 slat position drive cables are within the limits of 6,500 total landings or the 10,800 total landings specified in paragraphs (b) or (c) respectively, of this AD.

(f) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections required by this AD.

(g) Alternative inspections, modifications or other actions which provide an equivalent level of safety may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(h) For the purpose of complying with this AD, subject to acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours' time-in-service by the operator's fleet average time from takeoff to landing for the airplane type.

Amendment 39-3514 became effective July 13, 1979.

This amendment 39-3565 becomes effective September 24, 1979.