TB 1-1520-238-30-20
16. MODIFICATION OF A-MODEL INTERMEDIATE GEAR BOX FAIRING INTO D-MODEL OR ECP 1315
FAIRING:
16.1. Remove the IGB Fairings 7-311122620-47 and -48 per applicable maintenance manual: see reference
16.2. Mark trim-line of fairing per dimensions in Figure 6. Split the -47 and -48 fairings using Die Grinder with
a cutting wheel. Allow a .20 gap when re-aligned.
16.3. Trim internal baffle of -47 fairing as shown in Figure 8.
16.4. Remove grommets, studs, washers, and ejector springs in areas indicated for holes to be filled (4
places) per Figure 6.
16.5. Fill holes with EA9313 per Figure 6.
16.6. Lay up a 1.6" X 1.6" sheet of Kevlar cloth using same EA9313.
16.7. Position stiffeners, P/N 7-311122620-7 and -9, per dimensions in Figures 6 and 7. Bond using
EA9309.3NA.
16.8. Reinstall -47 and -48 fairing onto aircraft.
16.9. Install 3M 8641 Tape to the outsides of the -47 and -48 fairings maintaining a 0.20 inch gap as shown
in Figure 7. Prime fairing surface before installation using 3M #86 primer per manufacturer's instructions.
16.10. Remove right and left fairings, taking care to maintain tape gap between two halves of each side.
16.11. Powder exposed sticky tape surface between both fairing halves with Talcum Powder to prevent
surface from retaining FOD.
16.12. Apply a fillet of AMS-S-8802 CLB-2, sealant to the forward and aft edges of the rubber strips.
16.13. Apply Anti-Chafe tape per Figure 6 to both fairing halves.
16.14. Touch-up all rework areas using MIL-PRF-23377 and MIL-C-46168 exterior paint.
16.15. Re-identify the -47 fairing to 7-511122620-3 and the -48 to 7-511122620-5 per MIL-STD-130, and
HP8-5 Ink Permenent Marking, 30001 Black.
17. MODIFICATION: ADD GUSSET TO UPPER SUPPORT LEG OF DIFFUSER:
17.1. Remove paint from repair area, shown in Figure 5.
17.2. Remove rubber extrusion seal (bulb seal) HS4028-2724 from Diffuser, as required.
17.3. Remove Naugahyde seals, 7-311332020-37 & -39, as required.
17.4. Fabricate two gussets from 0.090 inch 6061-T6 aluminum, 1.0 X 1.5 inch, triangular shape IAW Figure
17.5. Clean all surfaces to be welded with alcohol soaked, lint free cloth.
17.6. Inspect leg for signs of crack. If crack is not present, proceed to step 17.10.
17.7. If leg is cracked, cut "V" groove in crack location completely around support leg.
17.8. Clean "V" groove and welding rod, with alcohol soaked cloth.
17.9. Weld around "V" groove with TIG welding procedure using 4043 welding rod, HW 20 torch and 20 CFM
Argon flow.
17.10. Position gussets IAW Figures 1 and 5.
17.11. Weld gussets per above procedure.
17.12. Inspect repaired area IAW reference TM 1-1500-335-23 Nondestructive Inspection Methods.
17.13. Prepare repaired area for coating.
17.13.1. Clean surface with Trichloroethane.
17.13.2. Abrade surface with Abrasive Mat Scotchbrite.
17.13.3. Clean surface again with Trichloroethane and wipe dry with clean oil free paper or cloth wipers.
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