AC 20-64 CHG 1 10/26/73
LEAP DOUBLER -
ACCESS DOORS WS WS 584 567 550 533 516 499 482 9 DRAI 8 7 5 4 3 2 PLANK #1 WS
55.35 155
CENTROID RISERS
LEAP DOUBLER
WS WS W'S 516 499 359 293
FRONT SPAR
• INBD
DRAIN HOLE
INBOARD NACELLE FWD
SKATE ANGLES
- FUEL QUANTITY GAGE OUTI SKAT WS 359
LOWER PANEL RH
VIEW LOOKING UP
Appendix 6 Page 5 (and 6)
QUANTITY GAGE 7 3 2 →A WS 83
FUEL OVERFLOW
- PLANK
JPPER PANEL LH IDENTIFICATION -OOKING DOWN HORIZONTAL NUMBER CRACK
RD NACELLE VERTICAL
VGLES CRACK
SECTION A-A
• REAR SPAR TYPICAL PLANK SPLICE
CRACK ORIENTATION NOTE: LH AND RH WING
IDENTIFICATIONS
ARE THE SAME
WING SECTION
WS LOWER SURFACE 499 50 567 D FWD FIGURE F-2. Wing Section Lower Surface.
AC 20-64 CHG 1 Appendix 6 10/26/73 Page 7 FIGURE F-3. SERVICE PROBLEM AREAS Pages 8 through 27 (and 28) refer to various service problem areas and are cross-referenced to the photographs in figures Figures F-4 through F-32.
Appendix 6 AC 20-64 CHG 1 Page 8 10/26/73 2 4 5 6 PAGE REF.
MAJOR FOR S/N NO. ASSEMBLY ITEM SERVICE HISTORY ILLUST. CODE W-1 Outer Wing Leading Attach Loosening has occurred of the 29 Edge inboard, Screws screws attaching the leading 30 Middle, & Outboard Upper and edge skins to the front spar Sections Lower caps.
W-2 Outer Wing Lower No. 1 and 3 Surface depressions have been 31 Surface Planks reported in planks between Wing Stations 478 and 528.
W-3 Outer Wing Lower No. 4 Plank Cracks have occurred at the 32 Surface, W.S. 159.6 lower No. 4 wing plank drain hole adjacent to Wing Station
159.6.
W-4 Outer Wing Lower Rear Spar Loose and failed flap track 33 Surface | attachment bolts have been found.
AC 20-64 CHG 1 Appendix 6 10/26/73 Page 9 7 8 9 10
RECOMMENDATIONS
METHOD FREQUENCY TYPE OR METHOD
OF OF OF PREVENTIVE INSP. INSPECTION REPAIR ACTION Visual Inspect at 50 flight hours intervals Remove existing screws and Accomplish and retighten all screws each 300 replace with new type fasteners 88/SB-334.
hours until LAC 88/SB-334 is per 88/SB-334.
incorporated.
Visual Inspect within next 300 hour interval. If depressions exceed limits reinspect each 100 hours until corrective action is taken.
Replace H-clips per instructions Same as Column 9.
of LAC Service Bulletin 88/SB-564.
Externa I Visual Repeat inspections at 1000 hour intervals until permanent repair is incorporated. Interim repairs have special inspection requirements.
Visual Inspect within 850 hours and reinspect at 5000 hour intervals.
(1) Preventive/temporary Same as Column 9, repair may be effected by Item (2).
installing 5/16 Hi-Lok fasteners in drain holes per 88/SB-587C with continued 1000 hr. repeat inspections.
(2) Permanent repair/reinforcement can be made by incorporating either SED/63-9015-101 or SED/63-9015-135 shown on Dwg. SED/63-9015B.
Replace and/or tighten bolts Same as Column 9.
and rework bolt holes per LAC 88/SB-591A.
Appendix 6 AC 20-64 CHG 1 Page 10 10/26/73 2 3 4 5 6 PAGE REF.
MAJOR FOR S/N NO. ASSEMBLY ITEM SERVICE HISTORY ILLUST. CODE W-5 Outer Wing Lower Wing Plank Cracks have occurred in the 34 Surface, W.S. No. 7 wing plank surface and plank 35 179-197 riser located under the main landing gear actuating cylinder attach fitting angles, P/N 802699.
W-6 Outer Wing Lower support Fatigue cracks have occurred at 35 Surface, W.S. 187 Fitting, MLG the aft end of the MLG actuator 36 Actuator support fittings in the radius P/N 800618-1 of the vertical legs.
P/N 800618-2 P/N 800618-3 P/N 800618-4
AC 20-64 CHG 1 10/26/73 Appendix 6 7 8 9 10
RECOMMENDATIONS
METHOD FREQUENCY TYPE OR METHOD
OF OF OF PREVENTIVE INSP. INSPECTION REPAIR ACTION Visual Within next 2500 flight hours on A/C which have 88/SB-538 Requires incorporated. Otherwise, inspect removal of at 88/SB-538 incorporation, or 801266-1 within next 2500 fIt. hours, door (Dry whichever occurs first.
Repair wing plank skin and Same as Column 9.
riser cracks per Electra Structural Repair Manual, Section 57-2-1, Fig. 3, Sheets 41 thru 44, LAC Dwg. 841880, and LAC Bay A/C) 88/SB-593C. Repair & 800917 Repeat inspections at 2500 flt. out-of-round holes per LAC Door (Wet hour intervals are recommended. Service Bulletin 88/SB-593C.
Bay A/C) Visual, Dye Dye penetrant inspect original Penetrant 800618-3 & -4 fittings within 215 flight hours, Repeat at 425 flt. hrs. Visual dye penetrant inspect aft 4 in. of fittings at each 850 flt. hrs.
Visual inspect reworked fittings (radius on aft edge) at each 850 flt. hrs. and dye penetrant inspect at each 1700 flt. hrs.
No repeat inspections for new 841275-101, -102 fittings.
Install new 800618-3 or Install new fittings, 841275-101 (LH) and P/N 841275.
800618-4 or 841275-102 (RH) support fittings to replace damaged parts per LAC 88/SB-599A.
AC 20-64 CHG 1 Appendix 6 Page 12 10/26/73 2 3 4 5 6 PAGE REF.
MAJOR FOR S/N NO. ASSEMBLY ITEM SERVICE HISTORY ILLUST. CODE W-7 Outer Wing Upper Wing Planks Cracks up to three inches in 37 Surface under length have occurred under the nacelle inboard and outboard skate skate angles angles of the inboard nacelle.
W-8 Outer Wing Upper Fuel Tank Corrosion has been reported on 38 and Lower Surfaces Access lower wing plank access door Door Lands lands due to condensation.
AC 20-64 CHG 1 10/26/73 Appendix 6 7 8 9 10
RECOMMENDATIONS
METHOD FREQUENCY TYPE OR METHOD
OF OF OF PREVENTIVE INSP. INSPECTION REPAIR ACTION Visual (External, Initial external inspection at 450 Internal) flt. hrs. with repeat at next 450.
X-Ray Initial internal inspection at 900 fIt. hrs. with repeat at 3000 hr.
intervals. Discontinue inspections after 6000 hrs. if no cracks found.
(1) Repair cracks in planks per Same as Column 9, Electra Structural Repair I tem (2).
Manual, Section 57-2-1.
(2) Install skate angle attachment reinforcement at inbd. and outbd. nacelles per LAC Alert Service Bulletin 88/SB-600A (Ref: LAC Dwg.
841481).
Visual Within next 850 flt. hrs.
Reinspect at each overhaul period.
Remove corrosion per Electra Add protection per Structural Repair Manual 88/SB-606. Refer Section 51-2-14 and add to 88/SB-620G for protective coating per LAC access door gap Service Bulletin 88/SB-606. sealing Repair per LAC Drawing instructions.
841295 when damage exceeds .010 inch depth.
NOTE: Contact LAC for repair of damage which exceeds allowable limits of Dwg.
841295.
(Refer to 88/SB-620G for access door gap sealing instructions.)
Appendix 6 Page 14 AC 20-64 CHG 1 10/26/73 2 3 4 5 6 PAGE REF.
MAJOR FOR S/N NO. ASSEMBLY ITEM SERVICE HISTORY ILLUST. CODE W-9 Outer Wing Upper Wing Planks Cracks have occurred in the 39 Surface, W.S. 167 & at MLG Rib wing upper surface in the area 40 W.S. 209 Forgings of the MLG rib forgings.
W-10 Center Section Wing, Wing Planks Corrosion and cracks have 30 Outer Wing Upper and occurred at various locations in 37 Lower the upper and lower wing plank 38 Surfaces splices. 41 42 43 W-11 Outer Wing Lower Wing Plank Cracks have occurred in the 44 Surface, W.S. 167 & Nos. 3,4,5, lower wing No. 5 plank of the W.S. 209 & 6. LH inboard MLG fulcrum fitting at the No. 4 and No. 5 splice; also, at a fastener hole in plank No. 6 at approx. W.S.
211.
AC 20-64 CHG 1 10/26/73 Appendix 6 7 8 9 10
RECOMMENDATIONS
METHOD FREQUENCY TYPE OR METHOD
OF OF OF PREVENTIVE INSP. INSPECTION REPAIR ACTION Visua Initial inspection Install 0.063 inch thick Same as Column 9.
and dy e within 700 landings doublers under existing penetrant. with repeat inspections at 1400 external doublers and install Ultrasonic landing intervals. No repeat angle stiffeners on the wing and X-Ray inspections required after internal surface at the Plank may be used incorporation of reinforcements No. 3 & No. 4 splice on A/C in local described in LAC Service Bulletin S/N 1001, 1002, 1004 thru areas. 88/SB-619. 1144, and 2001 thru 2019.
Install new external doublers only on A/C S/N 1145 thru 1148 and 2020 thru 2022.
Accomplish rework per LAC Service Bulletin 88/SB-619A.
Ref. LAC Drawings 841314C, 841315C, 841345, 841346, SED/64-9010, SED/64-9011.
V is u al, Repeat inspection intervals As specified in LAC Service Accomplish Ultrasonic based on action taken. Bulletin 88/SB-620G. Service Bulletin 88/SB-620G.
Dy e Initial inspection As specified in LAC Service Same as Column 9.
Penetrant, within 700 landings Bulletin 88/SB-625D.
Ultrasonic with repeat inspections at 1400 landing intervals. Repetitive Seal plank splices under repairs inspections may be discontinued per 88/SB-620G.
after incorporation of LAC Service Bulletin 88/SB-625 reinforcements.