1C-5M-36_page 3-17.pdf

3.4 HORIZONTAL STABILIZER CHORDWISE SKIN SPLICE - UPPER SPLICE PLATE, BUTTOCK LINE 4 TO

BUTTOCK LINE 19, DRAWING 4T32076 (E-3).

3.4.1 Description. (See Figure 3-6.) These splice plates are located on the upper surfaces of the horizontal stabilizer at BL 4 to BL 19. The splice plates are 7075-T6 aluminum alloy, sulfuric acid anodized, and covered with zinc chromate primer.

3.4.2 Defects. Constant flexing of the horizontal stabilizer renders these splice plates susceptible to fatigue cracking around fasteners.

3.4.3 Primary NDI Procedure - Radiographic.

• RADIATION HAZARD

• Do not perform inspections requiring exit to the exterior surfaces of the horizontal stabilizer during thunder-storms or if the wind velocity is 20 knots (23 MPH) or greater. Failure to comply can result in injury to personnel.

• Ensure compliance with all applicable safety precautions set forth in TO 33B-1-1. Failure to comply may result in injury to personnel.

a. NDI equipment: X-Ray machine, portable, 160 KVP, 40-degree tube head, NSN 6635-01-394-5926.

• Personnel restraint harness must be used when working on the horizontal stabilizer or bullet fairing upper surfaces. For use, and attach points, refer to paragraph titled Personnel Restraint Equipment in Chapter 1.

Failure to comply may result in injury to personnel.

• Ensure that power is isolated from the pitch trim system prior to gaining access to inspection areas. Failure to comply may result in injury to personnel.

b. Preparation of aircraft:

(1) Place horizontal stabilizer in the faired position in accordance with TO 1C-5M-2-9-1.

(2) Isolate power from the pitch trim system in accordance with TO 1C-5M-2-9-1.

(3) Remove the center bullet access panels 7111-4, 7111-5, 7121-4, 7131-6, and 8121-4 in accordance with TO 1C-5M-2-1.

c. Access: Inspection areas are accessible by entering the fuselage afterbody through the maintenance door in the vicinity of FUS STA 2775 using appropriate AGE, climbing the ladder in the vertical stabilizer to the center bullet area, and exiting through the 7131-6 opening in the center bullet.

d. Preparation of part: No special preparation required.

e. X-ray machine settings: Set X-ray machine for the data indicated in the Radiographic Inspection Data block. This procedure is for a median film density of 1.8.

NOTE

For film marking location instructions, refer to paragraph titled Radiographic (X-Ray) Method in Chapter 1.

f. Film placement: Place X-ray film as illustrated and in the sequence specified. After each exposure, remove film and place film for next exposure. Use film specified in Radiographic Inspection Data block or equivalent.

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Tech data extract. Printed 16-Aug-2019. Currency must be validated and annotated every 7 days.

g. X-ray tube location: Locate X-ray tube and center X-ray beam as illustrated for each exposure.

h. Inspection: Make radiographs of the inspection area in accordance with Radiographic Inspection Data as illustrated.

i. Mark, record, and report defects as required.

j. To confirm defect condition, proceed with paragraph titled Backup NDI Procedure. If no defect is suspected, proceed to paragraph titled System Securing.

3.4.4 Backup NDI Procedure - Eddy Current. Anywhere required procedural guidance is not furnished in this part specific procedure, consult TO 33B-1-2, WP 404.

a. NDI equipment:

(1) Eddy Current Inspection Unit: Refer to TO 33B-1-2, WP 404.

(2) Probe: Bolt hole, 1/4-inch diameter, shielded, appropriate frequency for the material to be inspected.

(3) Calibration Standard: Aluminum AF General Purpose Eddy Current Standard.

(4) Scanner: Refer to TO 33B-1-2, WP 404.

b. Preparation of aircraft:

(1) Same as for Primary NDI Procedure.

(2) Remove access panels 7111-6, 7111-7, and 4T33017-101A, access doors 7111-1, 8111-1, 4T31018-103A, and 4T31018-104A and rib struts, as necessary, for access.

c. Access: Same as for Primary NDI Procedure.

All fasteners, except the one removed from the hole to be inspected, must be fully installed at all times. Failure to comply could result in difficulty in reinstalling fasteners or damage to aircraft.

d. Preparation of part: Remove fasteners from suspected defective fastener hole in accordance with TO 1C-5M-3. Refer to TO 1C-5M-23for cleaning instructions. Clean local inspection area, as necessary, to permit good contact between part and probe.

e. Instrument settings/calibration: Refer to TO 33B-1-2, WP 404.

f. Inspection: Scan entire depth of the suspected defective fastener hole.

g. Mark, record, and report defects as required. Refer to TO 33B-1-2, WP 404 for evaluation guidelines.

3.4.5 System Securing. Clean areas inspected, restore finishes, reinstall removed components, and perform operational checkouts, as required, in accordance with applicable technical orders.

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 1 of 7)

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 2)

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 3)

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 4)

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 5)

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 6)

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Figure 3-6. Horizontal Stabilizer Chordwise Skin Splice - Upper Splice Plate, Buttock Line 4 to Buttock Line 19 (Sheet 7)

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