Boeing 747 - Page 60

D. To make sure that the ultrasonic signals are not caused by sound transfer into the strut fitting lug, do
one of the steps that follow:
(1) Lift the engine and pylon to remove the load from the fuse pin. Refer to Service Bulletin
747-54A2153 for instructions on how to remove the weight of the engine and pylon from the fuse
pin. Do the inspection again. If the ultrasonic signal does not change to less than 40% full screen
height, reject the fuse pin.
(2) Remove the pin from the airplane. Do a magnetic particle inspection as specified in Service
Bulletin 747-54A2153.
E. To make sure there are cracks when you get ultrasonic indications with the fuse pin installed, do an
eddy current inspection as specified in Part 6, 51-00-00, Procedure 13. It will be necessary to first
remove all cadmium and corrosion from the inner diameter of the fuse pin. Refer to Service Bulletin
747-54A2153 for instructions on how to remove the cadmium and corrosion and how to refinish the
fuse pins after the inspection is done. To make sure there are cracks when you get ultrasonic
indications with the fuse pin removed from the airplane, do a magnetic particle inspection as specified
in Service Bulletin 747-A2153.
Table 1: Upper Link - Calibration Information
ENGINE
CONFIGURATION
FUSE
PIN
*[1]
STRUT
*[2]
POSITION ON THE
REFERENCE
STANDARD FOR THE
NOTCH AND THE BACK
SURFACE
TRANSDUCER GUIDE
NUMBER (Figure 3)
JT9D-70
-8 I/B C, D NDT4109-G2
-4 O/B C, B NDT4109-G2
JT9D-XXX (EXCEPT -70)
-7 I/B C, B NDT4108/9-G4
-7 O/B C, B NDT4108/9-G4
CF6-45, -50
-3 I/B C, B NDT4108/9-G4
-4 O/B C, B NDT4109-G2
RB211
(B), (C), (D)
-9 I/B C, D NDT4108/9-G3
-4 O/B C, B NDT4109-G2
RB211
(G), (H)
-9 I/B C, D NDT4108/9-G3
-21 O/B C, B NDT4109-G1
AIRPLANES
RB013-RB016
-3 I/B C, B NDT4108/9-G4
-4 O/B C, B NDT4109-G2
*[1]
BOEING PART NUMBER 69B90909
*[2] I/B = INBOARD; O/B = OUTBOARD
747
NONDESTRUCTIVE TEST MANUAL
PART 4 54-30-08
Page 4
Nov 15/2015D6-7170
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
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