R TASK 70-38-14-250-003

R HIGH FREQUENCY MHz MANUAL EDDY CURRENT INSPECTION OF FAN BLADE

R LEADING EDGE
R 1. General.
R A. This document describes the general equipment, techniques
R and procedures required to conduct high frequency MHz
R manual eddy current inspection of fan blade leading edge.
R B. The following requirements shall be met by inspection
R personnel:
R (1) Personnel performing this inspection shall be
R certified in accordance with NAS-410 or SNT-TC-1A
R or COSAC, or ATA 105 level 2.
R (2) Personnel performing this inspection should receive
R practical training in the use of this procedure and
R must demonstrate proficiency in the calibration and
R evaluation routines before accept/reject authority is
delegated
R (3) Training per this procedure does not imply personnel
R certification per NAS-410 or SNT-TC-1A or COSAC,
R Procedure EN4179.
R D. The following documents shall form a part of this procedure
R to the extend specified herein. Unless a specific issue
R is specified, the latest revision shall apply.
R (1) Appropriate equipment instruction manuals
R (2) NAS-410 and/or SNT-TC-1A and/or COSAC, EN4179, and/or
R ATA 105.
R (3) Appropriate Manual procedure.
R 2. Equipment.
R A. Instruments.
R (1) Eddy current instruments.
R (a) Nortec Model NDT-19, 19e, 19eII, 24 or -3000
R Eddyscope.

R 70-38-14
R Page 1
R May 31/2005
 (b) Rohmann Elostest B1 SDM Eddy current instrument.
B. Tools and Equipments.
(1) Special Tools.
Tool No. Description
R 856A2682G01 Kit containing
- a probe 9970 958 389P01, 3MHz, with a spring
blade
- a probe 9970 958 390P01, 3MHz, with a free
head
- a calibration bloc 9970 958 391G01
- 2 cables, Teflon tape, red and blue pencils

(2) Standard Tools and Equipment.

NOTE: This tooling will be contained in a CFMI
inspection kit. The inspection kit number
shall be identified in the applicable manual
procedure. A complete inspection kit
containing all required tooling can be obtained
from CFMI by contacting the following address:
North and South America Europe, Middle East and
and Asia customers. Africa customers
CFMI Inc. customers CFMI SA customers
CFM International CFM International
Quality Technology Center Snecma-Services
One Neumann Way, MD : QB Manager CFM56 Tooling Programms
Cincinnati, OH 45215 USA Site de Melun-Montereau
Attention : Brenda Tenley BP 1936
Phone : (513) 552 4701 77019 Melun Cedex
Fax : (513) 552 4892 France

70-38-14
Page 2
May 31/2006
R C. Consumable Materials.
R Code No. Description
R CP1040 Methyl Ethyl Ketone
R CP2189 Durite G 422
R CP2191 Durite G 421

R 3. Procedure.
R A. Preparation of the edge.
R (1) Clean the edge of the blade with Methyl Ethyl Ketone
R (CP1040).
R (2) If necessary, lightly remove the small surface defects
R with a thin abrasive cloth (CP2189) or (CP2191).
R B. Calibration.
R (1) Initial calibration.
R Frequency : 3 MHz
R Rotation : to be adjusted to have a vertical
R screen indicator
R Low Pass Filter : 100 Hz
R High Pass Filter : off
R Gain : to be adjusted during calibration
R procedure (ELOTEST –35dB, NORTEC
R -50dB

R (2) Calibration procedure with the 9970 958 389P01 or

R 9970 958 390P01 probe.
R CAUTION: MAKE SURE THAT THE PROBE IS IN GOOD CONDITION.
R LOOK FOR DAMAGED PROBE HEAD OR PROBE WIRE.
R (a) Install the probe on the Eddy current instrument

R 70-38-14
R Page 3
R May 31/2005
R CAUTION: TAKE CARE TO LET FREE THE MOBILE PART OF THE
R PROBE
R CAUTION: MAKE SURE THAT THE TEFLON IS CHANGED AT
R REGULAR TIME.
R (b) Apply a new small piece of Teflon tape on the
R coil of each probe.
R (c) Calibration.
R CAUTION: YOU MUST DO THE CALIBRATION AT THE
R BEGINNING AND THE END OF THE INSPECTION,
R EVERY FIFTH BLADE, AND AT ANY CHANGE OF
R ANY COMPONENT. YOU MUST PERFORM THE
R CALIBRATION OF THE INSTRUMENTATION HAS
R BEEN TURNED OFF.
R 1 Put the coil away from the notch of the Electro
R Discharge Machining (EDM) on the “not blended”
R area.
R 2 Set the EDM to zero.
R NOTE: The point is in the middle of the screen.
R 3 Examine surface along the “not blended” area
R with the probe and adjust the gain and rotation
R to have a peak to peak on full screen with a
R vertical indication when the coil touches the
R EDM notch. Refer to figure 1.
R 4 Keep the same parameters and put the coil away
R from the notch of the EDM.
R 5 Set the EDM to zero on the blended area.
R 6 Examine the bottom of the blended area with the
R EDM notch.
R 7 If the indication is equal or less than a half
R of full screen, adjust these following
R parameters :
R hand position, movement of examination, gain
R and rotation to have a full screen indication
R on the EDM notch of the “not blended” area and
R more than a half full screen in the “blended”
R area. Refer to figure 1.

R 70-38-14
R Page 4
R May 31/2005
R

R Indications (Typical)
R Figure 1

R 70-38-14
R Page 5
R May 31/2005
R C. Inspection Procedure.
R CAUTION: YOU MUST PERFORM TWO INSPECTIONS WITH TWO
R DIFFERENT PROBES BECAUSE OF THE DESIGN OF THE
R BLADE (SHAPE AND DIFFERENT THICKNESSES)
R ESPECIALLY IN THE BLENDED AREAS.
R (1) Do a first inspection of the leading edge of the blade
R with 9970 958 389P01 probe.
R (a) Put the probe in position with its coil in contact
R with the pressure face with the same adjustment
R than for calibration. Refer to figure 2.
R CAUTION: MAKE SURE THAT THE COIL IS ALWAYS IN CONTACT
R WITH THE INSPECTED AREA.
R (b) Move the probe to examine the surface along the
R leading edge.
R NOTE: You can perform this inspection a second
R time if it is not sufficient.
R (c) Put the probe in position with its coil in contact
R with the suction face with the same adjustment
R than for calibration. Refer to figure 2.
R CAUTION: MAKE SURE THAT THE COIL IS ALWAYS IN CONTACT
R WITH THE INSPECTED AREA.
R (d) Move the probe to examine the surface along the
R leading edge.
R NOTE: You can perform this inspection a second
R time if it is not sufficient.
R NOTE: You can move the probe three times or more
R across the blade section to make sure that
R the indication is not a malfunction.
R (e) Set to zero each time the probe touches a
R blended area.
R (2) Do a second inspection of the leading edge of the blade
R with 9970 958 390P01 probe.
R (a) Put the probe in position with its coil in contact
R with the pressure face with the same adjustment
R than for calibration. Refer to figure 2.

R 70-38-14
R Page 6
R May 31/2005
R

R Positioning of the Probes

R Figure 2

R 70-38-14
R Page 7
R May 31/2005
R CAUTION: MAKE SURE THAT THE COIL IS ALWAYS IN CONTACT
R WITH THE INSPECTED AREA.
R (b) Move the probe to examine the surface along the
R leading edge.
R NOTE: You can perform this inspection a second
R time if it is not sufficient.
R (c) Put the probe in position with its coil in contact
R with the suction face with the same adjustment
R than for calibration. Refer to figure 2.
R CAUTION: MAKE SURE THAT THE COIL IS ALWAYS IN CONTACT
R WITH THE INSPECTED AREA.
R (d) Move the probe to examine the surface along the
R leading edge.
R NOTE: You can perform this inspection a second
R time if it is not sufficient.
R NOTE: You can move the probe three times or more
R across the blade section to make sure that
R the indication is not a malfunction.
R (e) Set to zero each time the probe touches a
R blended area.
R D. Inspection Criteria.
R (1) If you measure in a blended or non-blended area an
R indication equal to or more than 25 percent of full
R screen, you must do the evaluation of the default.
R Refer to figure 1.
R (2) If you measure in a blended or non-blended area an
R indication equal to or more than 50 percent of full
R screen, you must discard the part. Refer to figure 1.
R D. Evaluation of the Default.
R (1) Make sure that the calibration procedure was done
R correctly.
R (2) Make sure that two check were done with the two probes,
R on suction and pressure faces around the area you
R examine.
R (3) If the indication equal to or more than 25 percent of
R full screen, discard the part. Refer to figure 1.

R 70-38-14
R Page 8
R May 31/2005
R (4) If you have no indication or an indication less than
R 25 percent of full screen, the part is acceptable.
R Refer to figure 1.

R 70-38-14
R Page 9/10
R May 31/2005