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
Appendix F BOEING SERVICE BULLETIN 747-53-2307 ENTRY DOOR NO. 5 CARGO - S-23 DOOR
- S-19
- S-12
- BL 0.00 13
- 5-4
- S-12
- 5-19
- 5-23
ENTRY DOOR NO. 5 STA 2360 SECTION 46 STA 1961.1 FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 24
Appendix F BOEING SERVICE BULLETIN 747-53-2307 Perform the following applicable action(s):
a _ For lap joint areas with cracking or corrosion completely through the skin, repair per 747 Structural Repair Manual Subject 53-30-03 prior to fu, ther pressurized flight
b. For missing or distressed fasteners, replace fastener per 747 Structural Repair Manual Subject 53-30-03, Figure 9 or 10, prior to next pressurized flight.
c. lap joint areas with skin bulging or pillowing in excess
0.010 inch, repair per 747 Structural Repaiz Manual Subject 53-30-03 unless the following three conditions have been met:
Inspection per 747 Non-Destructive Iest Manual D6-7170, Part 6, Subject 51-00-00, Figure 5 indicates that material loss does not exceed 10 percent.
No evidence of skin cracks or corrosion completely through the skin is found.
3. For Section 46, tear straps have been reworked by temporary repair or terminating action per Service Bulletin 747-53A2279 in adjacent area.
NOTE: Adjacent area refers to the area bounded by the 3 stringer bays above and below the applicable lap joint and the closest tear strap forward and aft of the corroded area.
Where corrosion is within 5 inches of a frame, the next distant tear strap from and not the tear strap closest to that frame determines that boundary.
d. For lap joint areas where measured material loss does not exceed 10 percent, reinspect per this service bulletin at 500 flight-cycles specified in the procedure (Method I or II) being used.
Terminating action must be performed on corroded lap joint (fron forward circumferential splice to aft circumferential splice) within 30 months of being found.
e. For lap joint areas where material loss is greater than 10 percent, repair per 747 Structural Repair Manual Subject 53-30-03 prior to next pressurized flight.
For any lap splice which is required to be repaired per 747 Structural Repair Manual Subject 53-30-03, terminating action must be performed on the remaining unrepaired length of the skin panel (from forward circumferential splice to aft circumferential splice of repaired skin panel) within 15 months of the repair. If existing repairs are found during the initial visual inspection of this bulletin, terminating action must be accomplished on the remaining unrepaired length of the skin panel within 15 months of being found.
FIGURE 2. EXTERNAL LAP JOINT CORROSION INSPECTION (CONTINUED) Dec 21/89 747-53-2307 Page 25
Appendix F BOEING SERVICE BULLETIN 747-53-2307 PS, P7. P12.
(AND P126)
OVERHEAD PANELS STA 332 STA 394 FLIGHT
ENGINEER'S STATION 260 _ LAVATORY AREA
PILOTS'
STATION
UPPER DECK
OBSERVERS
STATION
STOWAGE STA 340 AREA STA 520/
TYPICAL FLIGHT DECK INSTALLATION
ALL AFFECTED CONFIGURATIONS SIMILAR FIGURE 3. FLIGHT DECK LAP JOINT INTERNAL ACCESS Dec 21/89 747-53-2307 Page 26
Appendix F BOEING SERVICE BULLETIN 747-53-2307
STA UP STA 300 330 FIGURE 3. FLIGHT DECK LAP JOINT INTERNAL ACCESS Dec 21/89 747-53-2307 Page 27