66-04-02 LOCKHEED: Amdt. 39-187 Part 39 Federal Register January 29, 1966. Applies to Models 188A and 188C Series Airplanes.
Compliance required as indicated.
In order to detect and remove or repair damage, and to retard cracking induced by corrosion in the upper and lower wing plank splice areas and at the access door-to-plank splices, accomplish the inspections and repairs set forth herein, or an equivalent approved by the Chief, Aircraft Engineering Division, FAA Western Region. The inspection required by (a) must be continued until inspection of the same area in accordance with (b) and (c) has been accomplished.
(a) Within the next 100 hours' time in service after the effective date of this AD, unless already accomplished within the last 200 hours' time in service and thereafter at intervals not to exceed 300 hours' time in service from last inspection:
(1) Visually inspect internally for cracks the upper wing plank splice underlying tang riser radius adjacent to risers Nos. 29, 36, 43 and 50, in the wing area located between the upper inboard nacelle skate angles, except those areas covered with production doublers or repair doublers. (This area is shown in Item 5, Figure 3 and Riser Locations, Figure 4, of Lockheed Service Bulletin 88/SB-620E or later FAA-approved revision.
(2) For airplanes utilizing the area described in (a)(1) as an integral fuel tank, purge the tank and remove the sealant covering the inspection areas before each inspection. (This area is shown in Item 5 and upper 1/2 inch of aft face of Item 11, Figure 3 of Lockheed Service Bulletin 88/SB-620E or later FAA-approved revision.
(b) For airplanes on which the splice gap has been widened to a width of 0.070 0.010 inch and has been cleaned, sealed, and painted in accordance with Lockheed Service Bulletin 88/SB-620E, Sections 2.J. through 2.N., or later FAA-approved revision, accomplish the inspections set forth in (1) on the areas and at the times prescribed in (2), except those areas covered with production doublers or repair doublers.
(1) Visually inspect for corrosion around fastener heads and for bulging between fasteners and along the wing plank edge, and ultrasonically inspect for corrosion and cracks in the wing plank splices in accordance with the Accomplishment Instructions of Lockheed Service Bulletin 88/SB-620E, Section 2.B or later FAA-approved revision.
(2) Inspect the areas described in Column 1 of the following table at the time specified in Column 2 unless already accomplished within the time specified in Column 3. These inspections must be repeated once at the time interval specified in Column 4 and thereafter at the time interval specified in Column 5 beginning at the time of the last inspection.
AREA
(Col.1)
INITIAL
TIME
(Col. 2)
LAST
INSPECTION
(Col. 3)
1st
REPETITIVE
(Col. 4)
REPETITIVE
(Col. 5)
UPPER WING SURFACE
2. Under fuselage fillets
1400
2600
40008000
3. Between fillet and wing station 83
1400
2600
4000
8000
4. Around inboard fuel tank access door
700
3300
4000
8000
5. Between nacelle skate angle & wing station 155
700
3300
4000
8000
6. Between nacelle skate angle & wing station 221
700
3300
4000
8000
7. Between wing station 221 & 257 at planks 2-3 splice & planks 3-4 splice
1400
2600
4000
8000
8. Around outboard fuel tank access door
700
3300
4000
8000
9. Around fuel probe access door
1400
2600
4000
8000
10. All remaining splices except center section wing between fuselage fillets
2000
2000
4000
8000
LOWER WING SURFACE
2. Under fuselage fillets
1400
6600
8000
8000
3. Between fillet & wing station 83
1400
6600
8000
8000
4. Between nacelle skate angles & wing sta. 155 & 221
700
7300
8000
8000
5. Around access doors
14006600
8000
8000
6. All remaining splices except center section wing between fuselage fillets
2000
6000
8000
8000
(c) For airplanes on which the splice gap has not been widened to a width of 0.070 + 0.010 inch in accordance with Lockheed Service Bulletin 88/SB-620E, Section 2.C(a), accomplish any one of the following:
(1) Inspect in accordance with the provisions of (b)(1) at the times specified for initial inspection set forth in (b)(2), accomplish the requirements of (d), widen all unwidened joints to a width of 0.070 + 0.010 inch, and clean, seal, and paint the joints, unless already accomplished, in accordance with Lockheed Service Bulletin 88/SB-620E, Sections 2.J. through 2.N., or later FAA-approved revision. These requirements must be accomplished on those areas specified in the table set forth in (b), except areas covered by production doublers or repair doublers. The inspections must be repeated at the intervals specified in the table set forth in (b).
(2) Inspect in accordance with the provisions of (b)(1) at the times specified for initial inspection set forth in (b) (2), accomplish the requirements of (d), and clean, seal, and paint the unwidened joints, unless already accomplished, in accordance with Lockheed Service Bulletin 88/SB-620E, Sections 2.J., through 2.N., or later FAA-approved revision. These requirements must be accomplished on those areas specified in the table set forth in (b), except areas covered by production or repair doublers. The inspections must be repeated once within a time interval of not less than 1800 hours' time in service and not more than 2200 hours' time in service from the time the splices were sealed, after which the repetitive inspection intervals specified in the table set forth in (b) may be used.
(3) Widen the splice gap to a constant width of 0.070 + 0.010 inch, if not previously accomplished, and visually inspect for corrosion around fastener heads and for bulging between fasteners and along the wing plank edge, and in the wing plank splices in accordance with the instructions of Lockheed Service Bulletin 88/SB-620E, Section 2.B. or later FAA-approved revision. If corrosion is detected in the skin riser radius of the underlying tang, inspect the radius for cracks by the dye penetrant procedure described in Lockheed Service Bulletin 88/SB-620E, Section 2.C. or later FAA-approved revision. These requirements must be accomplished on those areas and at the time specified for initial inspection set forth in (b)(2), except areas covered by production doublers or repair doublers. Accomplish the repairs as necessary in accordance with (d). These inspections must be repeated at intervals not to exceed 1000 hours' time in service from the last inspection until the joints have been cleaned, sealed, and painted in accordance with Lockheed Service Bulletin 88/SB-620E, Sections 2.J. through 2.N., or later FAA-approved revision after which the repetitive inspection intervals specified in the table set forth in (b) may be used.
(4) Inspect in accordance with the provisions of (b)(1), the areas specified in the table set forth in (b)(2), except those areas covered by production doublers or repair doublers, at the time specified for initial inspection set forth in that table. Accomplish the repairs as necessary in accordance with (d). These inspections must be repeated at intervals not to exceed 1,000 hours' time in service from the last inspection until the provisions of (1) or (2) are accomplished.
(d) Remove all corrosion and cracks found during the inspections performed in accordance with (a), (b), and (c) before further flight, in accordance with the instructions provided in Lockheed Service Bulletin 88/SB-620E, Sections 2.E. and 2.F. or later FAA-approved revision, except that removal of corrosion damage that does not exceed the limits of Lockheed Service Bulletin 88/SB-620E, Section 2.G. or later FAA-approved revision, may be deferred for an interval not to exceed 300 hours' time in service. Repair all areas where material removed exceeds the limits of Lockheed Service Bulletin 88/SB-620E, Section 2.G. or later FAA-approved revision, before further flight in accordance with the instructions provided in Lockheed Service Bulletin 88/SB-620E, Sections 2.O. and 2.P., or 2.O. and 2.Q. or later FAA-approved revision. If a repair described in Section 2.P. is used, the instructions in 2.P. pertaining to special inspections, inspection intervals, and additional repairs must be complied with. The airplane may be flown in accordance with FAR 21.197 to a base where the corrosion removal and repairs can be performed.
(e) Within 4,000 hours' time in service after December 29, 1966, for airplanes with splices sealed before that date, and within 4,000 hours' time in service after the splices are sealed for airplanes with splices sealed after December 29, 1966, and thereafter at intervals not to exceed 2,000 hours' time in service from the date of the last inspection:
(1) Visually inspect splices, except areas covered by production doublers or repair doublers, or enclosed by fillets and nacelle structure, for looseness of sealant.
(2) Re-seal any loose areas in accordance with Lockheed Service Bulletin 88/SB-620E, Sections 2.J. through 2.N., or later FAA-approved revision.
(f) 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 that operator.
(g) The inspection provisions of (b)(2) table, columns 2, 3, and 4, of this revision, are considered to have been previously accomplished if, prior to the effective date of this revision, inspections were accomplished in accordance with theprovisions listed in (b)(2) table, columns 2, 3, and 4, of Amendment 39-187, AD-66-04-02. In addition, the repairs accomplished in accordance with AD 66-04-02 are not affected by this amendment.
(Lockheed Service Bulletin 88/SB-620D covers this same subject).
This directive effective January 29, 1966.
Revised February 11, 1966.
Revised April 26, 1966.
Revised December 29, 1966.
Revised February 18, 1967.