C. Make a record of all ultrasonic signals that are less than 40% full screen height so you can refer to
these records when you do this inspection again.
D. To make sure that the ultrasonic signals are not caused by sound transfer into the wing attach fitting,
do the steps that follow:
(1) Lift the engine and pylon to remove the load from the fuse pin. Refer to Service Bulletin
747-54A2153 to remove the weight of the engine and the 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 or 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 747-54A2153.
Table 1: Diagonal Brace Fuse Pins
ENGINE
CONFIGURATION
AND FUSE
PIN PART
NUMBER STRUT
*[1]
FUSE PIN BACK SURFACE SIGNAL
INTERNAL
REFLECTION
POSITION
RANGE
%FSW
*[2]
TRANSDUCER
GUIDE
POSITION
METAL DISTANCE POSITION
IN. MM %FSW
*[2]
JT9D-70
65B94182-6
65B94182-7
I/B 3.217 81.7 64% 20% - 22% B
O/B 4.115 104.5 82% 25% - 35% C
JT9D-XXX
(EXCEPT -70)
65B90394-7,
-10, -601, -604
I/B 3.478 88.3 70% 19% - 30% C
65B90394-6,
-9, -600, -603
O/B 3.598 91.4 72% 22% - 27% A
CF6
69B89612-4
65B94182-2
I/B 3.478 88.3 70% 23% - 25% C
65B90394-6 O/B 3.598 91.4 72% 20% - 30% A
RB211
69B89612-4 I/B 3.478 88.3 70% 23% - 25% C
69B89612-6 O/B 4.115 104.5 82% 25% - 35% C
AIRPLANES
RB013-RB016
65B94182-2 I/B 3.478 88.3 70% 23% - 25% C
65B90394-6 O/B 3.598 91.4 72% 20% - 30% A
747
NONDESTRUCTIVE TEST MANUAL
PART 4 54-30-07
Page 4
Nov 15/2015D6-7170
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
EFFECTIVITY
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