Blending of First Stage Fan Blades. [CFMI]
TASK 72-21-00-320-001-A
Blending of First Stage Fan Blades.
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Job Set-up
Subtask 72-21-00-941-058-A ** ON A/C NOT FOR ALL
Subtask 72-21-00-020-058-A ** ON A/C NOT FOR ALL
Subtask 72-21-00-869-057-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.02 06:33:40 UTC
Blending of First Stage Fan Blades.
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE |
| No specific | AR | FILE - SMOOTH |
| No specific | AR | LIGHT SOURCE - WHITE |
| No specific | AR | MAGNIFYING GLASS POWER 10X |
| No specific | AR | WARNING NOTICE(S) |
| 856A2682G01 | 1 | EDDY CURRENT INSTRUMENT |
| 856A2802 | 1 | TEMPLATE CHECKING FAN BLADE LEADING EDGE |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP1039) | acetone |
| (Material No.CP1041) | isopropyl alcohol |
| (Material No.CP2011) | stoddard solvent |
| (Material No.CP2189) | durite G422 |
| (Material No.CP2191) | durite G421 |
| (Material No.CP2559) | ardrox 552 |
| (Material No.CP2560) | turco ind 79 |
| (Material No.CP2566) | mag-chem teksol |
| (Material No.CP2584) | degreasol 99 R |
| (Material No.CP2656) | mag-chem skysol |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 70-51-00-230-001-A | Fluorescent-Penetrant Inspection-Portable Water-Washable |
| TASK 70-52-00-250-001-A | Eddy-Current Inspection of the Fan Blade Leading Edge |
| TASK 72-00-00-200-005-A | Over-Serviceable-Limit Extensions |
| TASK 72-21-00-000-003-A | Removal of the Fan Rotor Blades |
Subtask 72-21-00-941-058-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
(4) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position.
4. Procedure(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
(4) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position.
Subtask 72-21-00-020-058-A ** ON A/C NOT FOR ALL
A. Remove the damaged fan blades, if necessary. (Ref. AMM TASK 72-21-00-000-003)
Subtask 72-21-00-220-050-A ** ON A/C NOT FOR ALL NOTE: If 5 fan blades or more have leading and/or trailing edge blend repaired over 0.5 in.2 (322.6 mm2), perform trim balance operation. It is recommended that location of repaired blades be recorded to perform trim balance operation when 5 further blades are repaired.
B. Do a check for dimensions and locations of the defects on the two edges, and compare with the repair limits or using template 856A2802 TEMPLATE CHECKING FAN BLADE LEADING EDGE (G01).
Subtask 72-21-00-320-050-A ** ON A/C NOT FOR ALL C. Do the blending operation as follows:
SPM 704111 using a FILE - SMOOTH or strips of durite G422 (Material No.CP2189) or durite G421 (Material No.CP2191) grade 150 or 180, used dry. The blended areas must make a smooth transition into the surrounding areas.
(3) If a large or deep blend is required, a low speed power tool equipped with an appropriate titanium grinding tool may be used to shorten the time required to remove the metal perSPM 704112 but you must complete with hand blending as told above.
Subtask 72-21-00-110-050-A ** ON A/C NOT FOR ALL CAUTION:
WHEN YOU USE POWER GRINDING OR BLENDING TOOLS, MAKE SURE THAT THE ENGINE BLADE DOES NOT BECOME TOO HOT. IF THE BLADE BECOMES TOO HOT, LET IT COOL BEFORE YOU CONTINUE THE REPAIR. TOO MUCH HEAT DURING GRINDING OR BLENDING CAN MAKE THE BLADE WEAKER.
(1) Remove the surface damage from the blade airfoil per NOTE: To prevent axial scratches, always do the blending in a longitudinal direction, parallel with the length of the blade.
NOTE: Remove a minimum of 0.01 in. (0.25 mm) of base metal in addition to depth of defect from the leading and trailing edges.
(2) Complete the blending with strips of durite G422 (Material No.CP2189) grade 400 or 800, used dry. The surface finish (roughness) on blended areas must be as close as pratical to the original finish. (3) If a large or deep blend is required, a low speed power tool equipped with an appropriate titanium grinding tool may be used to shorten the time required to remove the metal per
NOTE: Reworked contour must conform to original contour.
D. Clean the Blade:
Subtask 72-21-00-230-050-A ** ON A/C NOT FOR ALL CAUTION:
TITANIUM PARTS REQUIRE THE USE OF NON-HALOGENATED SOLVENTS.
(1) Clean blade using isopropyl alcohol (Material No.CP1041) or acetone (Material No.CP1039) or stoddard solvent (Material No.CP2011) or ardrox 552 (Material No.CP2559) or turco ind 79 (Material No.CP2560) or mag-chem teksol (Material No.CP2566) or degreasol 99 R (Material No.CP2584) or mag-chem skysol (Material No.CP2656) . E. Do an Inspection of Blended Area.
(1) Do a fluorescent inspection (Ref. AMM TASK 70-51-00-230-001) or do an eddy current inspection with 856A2682G01 EDDY CURRENT INSTRUMENT (856A2682G01) (Ref. AMM TASK 70-52-00-250-001) of blended area for cracks. No crack is permitted.
(a) Put it on the leading edge of the blade on concave side so that the tabs touch the leading edge and the midspan shroud fillet radius with airfoil.
(b) If the repairs of the leading edge go beyond the red line engraved on the template, replace the blade.
5. Close-up(1) Do a fluorescent inspection (Ref. AMM TASK 70-51-00-230-001) or do an eddy current inspection with 856A2682G01 EDDY CURRENT INSTRUMENT (856A2682G01) (Ref. AMM TASK 70-52-00-250-001) of blended area for cracks. No crack is permitted.
NOTE: If you did the blending operation on the leading edge in areas B, C and D, you can delay the fluorescent-penetrant inspection by 10 flight cycles or 25 flight hours.
In this case, you must do a visual inspection with a MAGNIFYING GLASS POWER 10X under LIGHT SOURCE - WHITE, to make sure that the damage is fully removed.
(2) If necessary, repeat blending and inspection until no crack is detected. Refer paragraph A to paragraph E. (1). In this case, you must do a visual inspection with a MAGNIFYING GLASS POWER 10X under LIGHT SOURCE - WHITE, to make sure that the damage is fully removed.
NOTE: If the blend depht is greater than the maximum, you can keep the blade in service for a limited period after repair. (Ref. AMM TASK 72-00-00-200-005).
(3) If you have a template, (856A2802G01), use it after the blending of the leading edge as follows: (a) Put it on the leading edge of the blade on concave side so that the tabs touch the leading edge and the midspan shroud fillet radius with airfoil.
(b) If the repairs of the leading edge go beyond the red line engraved on the template, replace the blade.
Subtask 72-21-00-869-057-A ** ON A/C NOT FOR ALL
A. Make sure that the work area is clean and clear of tools and other items.
Subtask 72-21-00-942-056-A ** ON A/C NOT FOR ALL B. Close Access
(1) Remove the access platform(s).
(2) Remove the WARNING NOTICE(S).
(1) Remove the access platform(s).
(2) Remove the WARNING NOTICE(S).
Stage 1 Fan Rotor Blades - Blend Limits