(5) Transducer Positioner - Make Transducer positioner number NDT4123P as specified in Figure 5
and Table 2.
(6) Couplant - All ultrasonic couplants that will not cause damage to the airplane structure can be
used. Commercial grease or oil can be used if the sensitivity requirements of Paragraph 4. are
satisfactory.
3. Prepare for the Inspection
A. Identify the inspection locations. See Figure 1.
B. Get access to the inspection surfaces of the fuse pin.
C. Remove all paint and sealant from the area of the fuse pin that the transducer will touch and clean fully.
Use a non-abrasive scraper to remove the paint. The part number is etched on the end of the fuse pin
and can cause the surface to be rough. If necessary, lightly sand this area by approved methods to
permit the transducer to fully touch the part.
NOTE: Make sure that the part number is not removed when you sand the fuse pin.
D. Find the part number on the fuse pin to be examined or refer to Table 1 to get the fuse pin part number.
4. Instrument Calibration
A. Calibration for all but the 65B94182-8 Fuse Pins
NOTE: Because of the small transducer size, a transducer guide is used during the inspection.
(1) Get reference standard NDT4115 and transducer guide NDT4120G1 as shown in Table 2.
(2) Connect the transducer to the instrument and do the initial adjustments of the instrument.
NOTE: Do not use reject unless the instrument has certified linear reject. Do not use more than
10% reject.
(3) Set the instrument frequency to 10 MHz. See Paragraph 2.A.(1).
(4) Put couplant at position 1 on the reference standard. Put the transducer at this position. See
Figure 6.
(5) Adjust the instrument controls to get the first back surface signal at 50% of full screen width and
the second back surface signal at 100% of full screen width. The instrument is now calibrated for
a 5.0 inch (127 mm) instrument screen range. See Figure 6.
(6) Refer to Table 1 to get the correct hole position to use in the transducer guide.
(7) Put the transducer into the correct hole position of the transducer guide.
(8) Make sure the transducer fully touches the surface of the reference standard.
(9) Put couplant on the reference standard at position X as shown in Figure 7. Put the transducer at
this position. The back surface signal must occur near 82% of full screen width.
NOTE: Signals can occur between 18% and 35% of full screen width that are caused by internal
reflections at the near end bottleneck on some fuse pins (see Figure 7, Detail I).
(10) Move the transducer guide above reference notch 1 at position Y (see Figure 7). The screen
location for the reference notch 1 signal must be at 55% of full screen width as shown in Figure 7.
(11) Move the transducer guide above reference notch 2 at position Z (see Figure 7). The screen
location for the reference notch 2 signal must be at 65% of full screen width as shown in Figure 7.
747
NONDESTRUCTIVE TEST MANUAL
PART 4 54-30-10
Page 2
Nov 15/2015D6-7170
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
EFFECTIVITY
ALL
To Next Page
Loading...
