PART 4 - ULTRASONIC
FUSE PIN 65B94182, 69B89612, 65B90341 AND 69B90410 INSPECTION AT THE FORWARD END
OF THE NACELLE DIAGONAL BRACE
1. Purpose
A. Use this procedure to examine fuse pins 65B94182, 69B89612, 65B90341 and 69B90410 for cracks.
These fuse pins are installed at the forward end of the nacelle diagonal brace (see Figure 1). Cracks
have been found to occur circumferentially on the inside diameter of the fuse pin. The minimum crack
size that can be satisfactorily found with this procedure is 0.085 inch deep by 0.25 inch long (2.2 mm x
6.4 mm). Two inspections are necessary to do on each fuse pin; one inspection from the inboard end
and one inspection from the outboard end. Use this procedure to do the ultrasonic inspections on the
inboard and outboard fuse pins of struts 1 thru 4. See Figure 1.
B. Service Bulletin Reference: 747-54-2066, 747-54A2153
2. Equipment
NOTE: Refer to Part 1, 51-01-00 for data about the equipment manufacturers.
A. All ultrasonic equipment that can do the calibration instructions of this procedure can be used.
(1) Instrument - It is necessary to do an ultrasonic instrument that can operate at 10 MHz. Broadband
instruments can be used if they can do the calibration instructions of this procedure. These
instruments were used to prepare this procedure:
(a) Epoch 2002; Panametrics
(b) Sonic-136; Staveley Instruments, Inc.
(c) USN 50; Krautkramer Branson
(2) Transducer - It is necessary to use a zero degree longitudinal wave transducer with a crystal
diameter not larger than 0.125 inch (3.2 mm). A case diameter not larger than 0.192 inch (4.9
mm) is necessary for good sensitivity. A 10 Mhz transducer is recommended but other
frequencies can be used if the instrument can be calibrated as specified in Paragraph 4. These
transducers were used to prepare this procedure:
(a) A 10 Mhz, 0.125 inch diameter (3.2 mm), 0 degree transducer. Case dimensions: 0.190 inch
diameter (4.8 mm) by 0.60 inch long (15 mm). Part number: 389-002-190. Manufacturer: KB
Aerotech
(b) A 10 Mhz, 0.125 inch diameter (3.2 mm), 0 degree transducer. Case dimensions: 0.192 inch
diameter (4.9 mm) by 0.60 inch long (15 mm). Part number: SUC 175. Manufacturer:
Search Unit Systems (Division of NDT Product Engineering).
(c) A 10 Mhz, 0.125 inch diameter (3.2 mm), 0 degree transducer. Case dimensions: 0.190 inch
diameter (4.8 mm) by 1.00 inch long (25.4 mm). Part number: Y-M-1/8-10. Manufacturer:
Nortec (Staveley, Inc.)
NOTE: Transducers of frequencies between 5 MHz and 12 MHz can be used if they can be
calibrated with the instrument as specified in Paragraph 4.
(3) Reference Standards - Make Reference Standards NDT4115 and NDT4123 as specified in
Figure 2 and Figure 3 and Table 2.
(4) Transducer Guide - Make transducer guide number NDT4120G1 as specified in Figure 4 and
Table 2.
747
NONDESTRUCTIVE TEST MANUAL
PART 4 54-30-10
Page 1
Nov 15/2015D6-7170
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
EFFECTIVITY
ALL
To Next Page
Loading...
