Appendix F BOEING SERVICE BULLETIN 747-53-2307 III. ACCOMPLISHMENT INSTRUCTIONS NOTES: 1. The following paragraphs outline the general accomplishment instructions. The suggested sequence of operations and detailed accomplishment instructions are indicated by circle notes on the figures.
Observe all warning and caution notes in the referenced manual sections.
3. Figure 1 contains the Logic Diagram presentations of the following general accomplishment instructions.
A For all lap joints affected by this bulletin as identifed by Figure 2, perform inspection of the lap splices using the method outlined in the logic diagrams of Figure 1.
Method I Within 1,000 flight-cycles after receipt of this bulletin, perform a detailed external visual inspection of the affected lap splices per Figure 2 circle notes 1 and 3.
Repair any corrosion beyond limits or cracking as specified in Figure 2 circle note 3.
Repeat the detailed external visual inspection at intervals not to exceed 1,000 flight-cycles for the affected lap splices in Section 41, 42, and 46. Repeat the detailed external visual inspection at intervals not to exceed 2,000 flight-cycles in Section 44.
B. In lieu of continued reinspections, terminating action may be accomplished.
Terminating action is accomplished when an uncorroded lap joint area is separated between adjacent circumferential splices, adbesive removed, faying surface sealant is applied, and joint is refastened per 747 Structural Repair Manual Subject 53-30- 03 Figure 9 or 10. Terminating action in a corroded or cracked lap joint area may be accomplished when the area is repaired per 747 Structural Repair Manual Subject 53-30-03. Internal lap joint access to accomplish terminating action can be NOTES: 1. When accomplishing terminating action either with airplane in a specific jacked position or without jacking the airplane, contact Boeing for allowable length of lap joint which may be reworked (specify details of airplane configuration including weight and CG, jacking configuration, and any other work being performed concurrently on the airplane).
2. When accomplishing terminating action on a specific lap joint length, contact Boeing for jacking requirements (specify lap joint being reworked, details of airplane configuration including weight and CG, and any other work being performed concurrently on the airplane›.
Dec 21/89 747-53-2307 Page 12
Appendix F BOEING SERVICE BULLETIN 747-53-2307 When refastening lap joint per Structural Repair Manual Subject 53-30-03 Figure 9 or 10, perform open hole HFEC inspection per 747 Non-Destructive Test Manual D6-7170, Part 6, 53-30-00, Figure 1, 3 or 4 to ensure the lap joint is crack free prior to resizing hole for installation oversize protruding head fasteners.
C. Restore airplane to normal configuration.
Dec 21/89 747-53-2307 Page 13
AC43-204 8/14/97 Appendix F BOEING SERVICE BULLETIN 747-53-2307 Illustration Table of Contents Title Page Figure 1. External Lap Joint Inspection Logic Diagram 12 Figure 2. External Lap Joint Corrosion Inspection and Repair 16 Figure 3. Flight Deck Lap Joint Internal Access 26 Figure 4. Upper Deck Lap Joint Internal Access 30
Figure 5. Main Deck Lap Joint Internal Access32
Dec 21/89 747-53-2307 Page 14
Appendix F BOEING SERVICE BULLETIN 747-53-2307 Inspection Method I Within 1,600 Flight-Cycles After Receipt of this Bulletin Perform the Following 1 Conduct a Detailed External Visual Inspection to Determine if Corrosion or Cracking Exists at Cold-Bonded Longitudinal Body Skin Lap Joints at S-23 and Above From Station 140 to 2360 (Ref Fig. 2) Areas of Cracks No Cracks or Corrosion or Corrosion Conduct Terminating Action on Affected Lap Joints Corrosion but Cracks No Cracks Conduct Terminating Action on Conduct Terminating Action Corroded Lap Joint Between on Remainder of Lap Joint Circumferential Splices Within Within 15 Months 3 30 Months Repeat Inspection of All Nonterminated Lap Joints In Sections 41, 42, 44 and 46 at 1,000 Flight Cycle Intervals FIGURE 1. EXTERNAL LAP JOINT INSPECTION LOGIC DIAGRAM Dec 21/89 747-53-2307 Page 15
AC 43-204 8/14/97 Appendix F BOEING SERVICE BULLETIN 747-53-2307
DISHING OF FASTENER HEAD / EXCESSIVE COUNTERSUNK DEPTH
CRACKS AT
FASTENER SHANK
2. Measuring of pillowing is accomplished by using a suitable straight edge and thickness gage. Minimum length of straight edge should be 4.50 inches. See below:
STRAIGHT EDGE
4.50 -
MIN OUTER SKIN
AT JOINT INBD
INNER SKIN AT JOINT
SKIN PILLOWING
DIMENSION (PILLOWING SHOWN EXAGGERATED FOR CLARITY) FIGURE 1. EXTERNAL LAP JOINT INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 16
Appendix F BOEING SERVICE BULLETIN 747-53-2307 Intentionally Left Blank Dec 21/89 747-53-2307 Page 17
AG 43-204 Appendix F 8/14/97 BOEING SERVICE BULLETIN 747-53-2307 STA 520 S-0 STA STA 400 340 STA 260 STA STA 220 S- 14 180 STA 140 A 100000 ENTRY DOOR NO. 1 S-19 0 0 S-23 Indicates area of visual inspections.
SECTION 41
LEFT SIDE FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION Dec 21/89 747-53-2307 Page 18
Appendix F BOLING SERVICE BULLETIN 747-53-2307
OUTER SKIN UP \INNER SKIN DINBOO
TYPICAL LAP JOINT
SECTION A-A FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 19
Appendix F BOLING SERVICE BULLETIN 747-53-2307 STA 520 S -0 STA 400 8000 4380 STA 340 STA 260 STA 220 5-14 SIA 180 STA 140 00000 00 S-19 1 • ON S-23 SECTION 41
RIGHT SIDE FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 20
Appendix F BOEING SERVICE BULLETIN 747-53-2307 ENTRY DOOR NO. WING BODY FAIRINGS CARGO DOOR S-23 5-19 S-12 S-6 S-0
STA RIGHT SIDE STA SECTION 42 1000 520 STA 941 A = S -0 S -6 S-12 S-19 S-23
WING BODY
FAIRINGS
STA STA STA 520 11000 LEFT SIDE ENTRY DOOR NO. 2 SECTION 42 FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 21
AO 43-204 8/14/97 Appendix F BOEING SERVICE BULLETIN 747-53-2307 ENTRY DOOR NO. 3
- S-23
- S-19
- S-12 S-41 BL 0.00
- 5-61
- S-12 A →
- S-19
- S-23 STA STA 1000 1241 ENTRY DOOR 1480 NO. 3 OFWD APPLICABLE TO RA001. RA005-RA014.
RA102. RA103 AND RA201 ONLY.
= INDICATES AREA OF VISUAL INSPECTION ONLY O SECTION 44 FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 22
Appendix F BOEING SERVICE BULLETIN 747-53-2307
WING/BODY
FAIRINGS ENTRY DOOR NO. 4 CARGO DOOR S-23
- S-19 -S -12
- S-4 13
- S -4 A -
- S- 12
- 5-19
- S-23
ENTRY DOOR NO. 4
STA STA 1480 FAIRINGS WING/BODY 1961.1 SECTION 46 FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 23