Over-Serviceable-Limit Extensions [CFMB]

TASK 72-00-00-200-025-A
Over-Serviceable-Limit Extensions

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

ZONE: 400
FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
This TASK is applicable to NON /P and NON /3 engines.
It can occur that specific defects do not agree with the "Maximum Serviceable Limits", and that the maintenance facilities, at a given location, are not sufficient to do the necessary corrective actions.
In these circumstances, limit extensions will permit to send the engine where correction is possible, or to schedule the necessary maintenance in the extension period.

NOTE: The limit extensions are one-time extensions only. Applicable hardware action is necessary at the completion of the extended serviceable period.

2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS

B. Referenced Information

REFERENCE	DESIGNATION
TASK 72-21-00-210-006-A	Inspection of the Fan Rotor Blades Removed from the Fan Disk
TASK 72-21-00-210-009-A	Inspection of Fan Rotor Blades Installed on the Fan Disk
TASK 72-23-00-000-008-A	Removal of the Fan Outlet Guide Vane (OGV) Doublets
TASK 72-23-00-210-003-C	Detailed Inspection of Spinner, Engine Inlet, Fan Blades, Fan Outlet and Abradable Material
TASK 72-23-00-400-008-A	Installation of the Fan Outlet Guide Vane (OGV) Doublets
TASK 79-00-00-210-003-A	Visual Inspection of the Oil System
Booster Rotor and Stator Damage Extended
Extended Vanes Damage Limits
Inspection/Check of the Fan Outlet Guide Vanes (OGV)
Outlet Guide Vane (OGV) Inner Platform for Missing Material
Measurements of Airfoil Indication on Low Pressure Turbine Blades (all stages)
Outlet Guide Vane (OGV) Inner Platform for Cracks
Cracks and Missing Material in the Dome Area

3. Job Set-up
Subtask 72-00-00-941-071-A ** ON A/C NOT FOR ALL

A. Not applicable

4. Procedure
Subtask 72-00-00-210-071-A ** ON A/C NOT FOR ALL

A. Over-serviceable-limit Extensions

CONDITION					MAX. EXTENSION
1.Fan and booster
A.Spinner front cone
(1)Corrosion marks (white mushroom pattern) before part removal.					A continuation in service of 100 cycles maximum is permitted.
B.Spinner rear cone
(1)Oil wetting at inner of spinner cone or fan disk or forward fan shaft.					50 cycles
(2)Seal ring tear: any number if cumulated length is more than 0.400 in. (10.16 mm).					50 cycles
C.Fan blade
(1)Fully missing molydag on inner faces of the platforms					250 cycles
(2)Flaking of Cu.Ni.In coating on blade dovetail pressure faces (contact areas), up to 10% if there is no indication of wear on base material.					Examine blades for serviceability (Ref. AMM TASK 72-21-00-210-006). 1200 cycles after relubrication. Repeat extension is permitted.
(3)Flaking of Cu.Ni.In coating on blade dovetail pressure faces (contact areas), more than 10% and less than 50% if there is no indication of wear on base material.					400 cycles after relubrication. Repeat extension is not permitted.
(4)Shingling at mid span shrouds					Turn the shingled blades to the 12 o'clock position and unshingle with hand force or by using a piece of wood. Examine blades for serviceability (Ref. AMM TASK 72-21-00-210-009). Remove and send the shingled blades to a shop for a dimensional inspection and an Fluorescent Penetrant Inspection (FPI) in less than 50 cycles.
(5)Nicks, dents, scratches and sheared edges on midspan shroud surfaces up to 0.035 in. (0.89 mm) deep if defects are not in the midspan shroud to airfoil fillet radius.					50 cycles
(6)Missing or damaged hard coating on midspan shroud pressure faces more than 20% but less than 40% of coated area.					50 cycles
D.Fan disk
(1)Wear greater than 50% of area on disk dovetail pressure faces.					100 cycles
E.Booster rotor blade for:
(1)Piece missing: any number in area G, at Leading Edge (LE) and Trailing Edge (TE) tip corners, 0.800 in. (20.32 mm) radial and 0.500 in. (12.70 mm) axial.					50 cycles or 75 hours (whichever comes first)
(2)Cracks and tears in area G, 0.800 in. (20.32 mm) from tip: any number, less than 0.800 in. (20.32 mm) radial and less than 0.492 in. (12.50 mm) axial.					50 cycles or 75 hours (whichever comes first)
(3)Wear or local distortion of TE and LE tips if less than 15 blades, 0.984 in. (24.99 mm) radial and 0.590 in. (14.99 mm) axial.					100 cycles or 150 hours (whichever comes first)
(4)Nicks, dents, scratches for area E: any number, less than 0.059 in. (1.50 mm) in diameter, protrusion acceptable, not thru.					50 cycles or 75 hours (whichever comes first)
(5)Nicks, dents, scratches for airfoil out of area E, not LE and TE: any number, less than 0.236 in. (5.99 mm) in diameter, protrusion acceptable.					50 cycles or 75 hours (whichever comes first)
(6)Nicks, dents, scratches out of area E on LE and TE: maximum axial length less than 0.059 in. (1.50 mm).					50 cycles or 75 hours (whichever comes first)
(7)Distorted LE and TE, out of area E: maximum circumference equals 0.275 in. (6.98 mm) radial length equals 0.708 in. (17.98 mm).					50 cycles or 75 hours (whichever comes first)
F.Booster vanes (stage 1 only) for:
(1)Piece missing: Maximum 20 blades more than 0.256 in. (6.50 mm) axial, 0.728 in. (18.49 mm) radial, no cracks starting from damage area allowed in areas A and B.					50 cycles or 75 hours (whichever comes first)
(2)Cracks and tears in area C, any number, more than 0.256 in. (6.50 mm) radial and 0.078 in. (1.98 mm) axial. In areas A and B, any number more than 0.128 in. (3.25 mm) radial and 0.039 in. (0.99 mm) axial.					10 cycles or 15 hours (whichever comes first)
(3)Distortion of TE and LE: any number, if the length L is not more than 1.000 in. (25.40 mm) and the maximum dimension X along the chord width is not more than 0.482 in. (12.24 mm).					50 cycles or 75 hours (whichever comes first)
(4)Nicks, dents, scratches for areas A and B: any number, less than 0.157 in. (3.99 mm) in diameter, protrusion permitted.					10 cycles or 15 hours (whichever comes first)
(5)Nicks, dents, scratches for area C: any number, less than 0.295 in. (7.49 mm) in diameter, protrusion permitted.					50 cycles or 75 hours (whichever comes first)
(6)Nicks, dents, scratches LE and TE maximum axial length less than 0.118 in. (3.00 mm) in diameter.					20 cycles or 30 hours (whichever comes first)
(7)Cracked inner shroud: maximum of four cracks extending from the LE to the TE of the inner shroud (passing through a recess) are permitted if there is a minimum separation of three non-cracked vane recesses between two cracked recesses.					3000 hours or "C" check (whichever comes first)
A sound check (see note below) done on the vanes at, and adjacent to the cracked inner shroud area, must demonstrate no difference in tonality.					This extension may be used again indefinitely in intervals of 3000 hours as long as there is no further deterioration of these conditions. NOTE: Sound tonality check recommendation. A sound tonality check must be done to detect if the abradable material inside the inner shroud is still in contact with the root of the vane. Use a smooth-ended cylindrical tool made of steel with diameter of approximately 0.500 in. (12.70 mm). (For example, a ratchet wrench extension bar). Tools made of aluminum, plastic or wood do not permit the detection of significant variation in the sound tone from one vane to the next. Removal of two or three fan blades gives a better accessibility to do the check. Be careful to not use a tool or excessive force during the check. This would damage the vanes. Do the check on an area including three or four vanes on each side of the vane where the cracked inner shroud is located. Place the tool on the LE mid-span of the counterclockwise most vane. Lightly stroke the vane and subsequent vanes in the clockwise direction using a constant speed. Note any variations in the sound tone from one vane to the next. If there is a difference between the vane where the recess is cracked and the other vanes, the stage 1 vane assembly is unserviceable.
(8)Vane LE and TE Nicks, dents and scratches on LE and TE in areas B and C with a maximum axial length less than 0.117 in. (2.97 mm).					10 cycles or 50 hours (whichever comes first)
Nicks, dents and scratches on LE and TE in area A with a maximum axial length of 0.117 in. (2.97 mm).					2 cycles or 10 hours (whichever comes first)
2.Fan frame
A.Fan frame
(1)Cracks, any number if maximum length of 0.160 in. (4.06 mm) and minimum separation of 1.000 in. (25.40 mm).					10 cycles or 25 hours (whichever comes first)
(2)Nicks and dents: any number					10 cycles or 25 hours (whichever comes first)
B.Fan inlet case
(1)Cracks: any number, if maximum length of 0.160 in. (4.06 mm) and minimum separation of 1.000 in. (25.40 mm).					10 cycles or 25 hours (whichever comes first)
(2)Nicks and scratches: any number					10 cycles or 25 hours (whichever comes first)
(3)Crater in abradable liner (length<5x width) and damage other than crack rub and circumferential defect: if the damage is within the maximum serviceable limit (Ref. AMM TASK 72-23-00-210-003), but the fan case parent metal is exposed and is confirmed via visual inspection to be undamaged.					50 cycles or 125 hours (whichever comes first)
(4)Grooves in abradable liner (oriented within 0 degree to 80 degree from engine axis and length>5x width: if the damage is within the MAX serviceable limit (Ref. AMM TASK 72-23-00-210-003), but the fan case parent metal is exposed and is confirmed via visual inspection to be undamaged.					50 cycles or 125 hours (whichever comes first)
(5)Circumferential defect in abradable liner (360 degree or oriented within 80 degree to 90 degree from engine axis): for one or a cumulated defect less than 2.000 in. (50.80 mm) if the fan case parent metal remains not damaged under visual inspection.					50 cycles or 125 hours (whichever comes first)
C.Outlet Guide Vanes (OGV) for: Inspection/Check of the Fan Outlet Guide Vanes (OGV) ** ON A/C NOT FOR ALL
(1)Broken vane: not serviceable, the broken vane has to be removed prior to next flight.					10-cycles extension if the broken vane is removed. A complete set inspection is required when a new doublet is installed. Replace the vane doublet (Ref. AMM TASK 72-23-00-000-008) and (Ref. AMM TASK 72-23-00-400-008).
(2)Missing vane: one doublet missing					10-cycles extension. A complete set inspection is required when a new doublet is installed. Replace the vane doublet (Ref. AMM TASK 72-23-00-000-008) and (Ref. AMM TASK 72-23-00-400-008).
(3)Transversal cracks on inner platform: not more than 30 transversal cracks per platform for the whole set: With no more than 15 transversal cracks included 5 opened transversal cracks maximum on area E. With no more than 15 transversal cracks included 5 opened transversal cracks maximum on area I. And with no more than 15 transversal cracks included 5 opened transversal cracks maximum on area M. Do not change the place of the cracked OGV on the engine for view of transversal cracks and opened transversal cracks. Outlet Guide Vane (OGV) Inner Platform for Cracks ** ON A/C NOT FOR ALL					750-cycles extension renewable after inspection.
(4)Cracks on outer platform: from or along the airfoil are defined in: Inspection/Check of the Fan Outlet Guide Vanes (OGV) ** ON A/C NOT FOR ALL					50-cycles extension
(5)Metal LE missing: up to 0.780 in. (19.81 mm) in height and 0.390 in. (9.91 mm).					100-cycles extension
(6)Nicks and/or dents, on LE (metallic LE), if damage between 0.120 in. (3.05 mm) and 0.190 in. (4.83 mm) deep.					A maximum service extension of 100 cycles.
(7)Erosion of composite material, any amount					50 cycles or 125 hours (whichever comes first)
Outlet Guide Vane (OGV) Inner Platform for Missing Material ** ON A/C NOT FOR ALL Less than 0.160 in.2 (103.23 mm2) on two platforms maximum. Do not change the place of OGV with missing material on the engine. No missing OGV allowed on the set.					10-cycles extension
Outlet Guide Vane (OGV) Inner Platform for Missing Material ** ON A/C NOT FOR ALL For five platforms maximum and no missing OGV allowed on the set. Do not change the place of OGV with missing material on the engine.					Outlet Guide Vane (OGV) Inner Platform for Cracks ** ON A/C NOT FOR ALL
D.OGV inner shroud
(1)Cracks, cut or torn seal at mating with OGV: any amount					25 cycles or 50 hours (whichever comes first)
E.Fan duct panels
(1)One fan duct panel missing is permitted, if you make sure that the Variable Bleed Valve (VBV) area is free of unwanted object before the first aircraft release of the day.					10 cycles
(2)Missing louvers on panel					50 cycles with 3 missing louvers maximum.
F.Splitter fairing
(1)Cracks: any amount					10 cycles or 25 hours (whichever comes first)
G.Mid acoustical panels (1)Disbonded damper more than 20% of the total surface.					20 cycles
3.Compressor rotor
A.Compressor rotor blades NOTE: The depth of a defect such as a nick is measured along the axis of the damage unless otherwise noted.
(1)Stages 1-4 radial cracks within 0.300 in. (7.62 mm) of the LE and TE more than 0.250 in. (6.35 mm) but less than 0.400 in. (10.16 mm) in length.					10 cycles or 25 hours (whichever comes first)
(2)Stages 1-4 chord-wise cracks more than 0.200 in. (5.08 mm) but less than 0.300 in. (7.62 mm) in length.					10 cycles or 25 hours (whichever comes first)
(3)Stages 1-4 nicks, missing material and erosion on the LE and TE found in Dim. B more than 0.040 in. (1.02 mm) but less than 0.080 in. (2.03 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(4)Stages 1-4 dents on the LE and TE found in Dim. B more than 0.040 in. (1.02 mm) but less than 0.080 in. (2.03 mm) in depth, and less than 0.060 in. (1.52 mm) deflection from the original contour.					10 cycles or 25 hours (whichever comes first)
(5)Stages 1 nicks, dents and tears on the LE and TE in Dim. A more than 0.250 in. (6.35 mm) but less than 0.300 in. (7.62 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(6)Stages 1-4 missing material and erosion at the LE and TE tip corners more than 0.300 in. (7.62 mm) but less than 0.400 in. (10.16 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(7)Stage 2, more than four blades missing material and erosion at the LE and TE tip corners more than 0.300 in. (7.62 mm) but less than 0.400 in. (10.16 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(8)Stage 3, more than five blades missing material and erosion at the LE and TE tip corners more than 0.300 in. (7.62 mm) but less than 0.400 in. (10.16 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(9)Stage 4, more than six blades missing material and erosion at the LE and TE tip corners more than 0.300 in. (7.62 mm) but less than 0.400 in. (10.16 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(10)Stages 1-4 nicks, dents and missing material on the LE and TE of the lower 25% of the airfoil (but not the root radius) more than 0.300 in. (7.62 mm) but less than 0.080 in. (2.03 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(11)Wear and scratches of the TE platform of stage 2 and stage 3 of more than 0.030 in. (0.76 mm) but less than 0.080 in. (2.03 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(12)Stages 2-3 TE root radius nicks, dents and scratches more than 0.030 in. (0.76 mm) but less than 0.080 in. (2.03 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(13)Stages 5-9 radial cracks that are not more than 0.200 in. (5.08 mm) from the LE or TE and more than 0.150 in. (3.81 mm) but less than 0.200 in. (5.08 mm) in length.					10 cycles or 25 hours (whichever comes first)
(14)Stages 5-9 chord-wise cracks that are not more than 0.200 in. (5.08 mm) from the tip and are more than 0.150 in. (3.81 mm) but less than 0.200 in. (5.08 mm) in length.					10 cycles or 25 hours (whichever comes first)
(15)Stages 5-9 nicks, tears, missing material and erosion on the LE and TE found in Dim. B that are more than 0.040 in. (1.02 mm) but less than 0.080 in. (2.03 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(16)Stages 5-9 dents on the LE and TE found in Dim. B that are more than 0.040 in. (1.02 mm) but less than 0.080 in. (2.03 mm) in depth and less than 0.060 in. (1.52 mm) deflection from the original contour.					10 cycles or 25 hours (whichever comes first)
(17)Stages 5-9 nicks, dents and tears on the LE and TE found in Dim. A that are more than 0.150 in. (3.81 mm) but than less 0.200 in. (5.08 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(18)Stages 5-9 missing material and erosion at the LE and TE tip corners if the damage is more than 0.200 in. (5.08 mm) but less than 0.300 in. (7.62 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(19)Stages 5-9 curl on the end of the airfoil when the blade chord is more than 50% but less than 75% of the chord maximum radial length, 0.300 in. (7.62 mm), when it does not engage the stationary parts during operation.					10 cycles or 25 hours (whichever comes first)
(20)Stages 5-9 nicks, dents and missing material edges found in the lower 25% of the airfoil (but not the root radius) more than 0.030 in. (0.76 mm) but less than 0.080 in. (2.03 mm) in depth.					10 cycles or 25 hours (whichever comes first)
(21)Two blade locks in the same stage with any number of cracks if no blade locks are loose on that stage.					10 cycles or 25 hours (whichever comes first)
(22)One loose blade lock in a stage if the other blade lock on the same stage is not loose or cracked.					10 cycles or 25 hours (whichever comes first)
4.Compressor front stator
A.Casing cracks: 0.170 in. (4.32 mm) maximum length in skin					10 cycles or 25 hours (whichever comes first)
B.Casing nicks, pits, scores or scratches, any amount, any depth					10 cycles or 25 hours (whichever comes first)
C.Broken actuation ring connector, one side only, if connector is replaced					5 cycles
D.Vane actuation ring cracks, distortion, bends, twists or distress, provided ring has not separated					5 cycles
E.Loose vane assemblies with metal-to-metal contact on up to 50% of vanes					10 cycles or 25 hours (whichever comes first)
5.Combustion case
A.Forward and aft flange radial cracks inward from bolt holes					10 cycles
B.Midflange radial cracks					10 cycles
C.Maximum of ten broken midflange bolts with no more than four broken bolts in any group of 20					25 cycles
D.High Pressure Turbine (HPT) shroud cooling and Compressor Discharge Pressure (CDP) pad cracks: more than 0.060 in. (1.52 mm) from bolt holes					10 cycles
6.Combustion chamber
A.Dome assembly
(1)Radial crack in spectacle plate					25 hours
Any number up to 2.500 in. (63.50 mm) in length and not connected to each other.
(2)Circumferential crack in spectacle plate					25 hours
Any number up to 3.600 in. (91.44 mm) in length separated by 4.800 in. (121.92 mm).
(3)Connected cracks in spectacle plate					25 hours
Not more than one radial crack 2.500 in. (63.50 mm) long with one circumferential crack 3.600 in. (91.44 mm) long, separated by 4.800 in. (121.92 mm).
(4)Missing material from spectacle plate					25 hours
The damage is more than the given limits.
(5)Radial crack in deflector or sleeve					25 cycles
Any number up to 0.600 in. (15.24 mm) in length.
(6)Circumferential cracks in deflector or sleeve					25 cycles
Any number up to 0.900 in. (22.86 mm) in length.
(7)Connected cracks in deflector or sleeve					25 cycles
Connection of any radial and circumferential cracks within limits of (5) and (6) above. Limit is exceeded when third crack connects.
(8)Up to 25 dome cooling holes total in any deflector are exposed. More than 25 exposed dome cooling holes total in any deflector.					100 cycles
(a)Up to 25 dome cooling holes total in any deflector are exposed.					Do BSI after each 750 cycles.
(b)More than 25 exposed dome cooling holes total in any deflector. Cracks and Missing Material in the Dome Area ** ON A/C NOT FOR ALL					25 cycles continue-in-service limit
(9)Missing material from extensions on sleeve
Any amount up to 0.240 in. (6.10 mm) maximum depth.					50 cycles
(10)Burn through holes					25 cycles
3 per dome 1.200 in. (30.48 mm) x 1.200 in. (30.48 mm) maximum.
(11)Cracks and missing material from the secondary swirl nozzle venturi
(a)Up to 10 secondary swirl nozzle venturis with total missing material at each venturi more than 0.100 IN. (2.54 MM) but not more than 0.300 IN. (7.62 MM) in width.					Do BSI after each 750 cycles.
(b)Any number of secondary swirl nozzle venturis with total missing material more than 0.300 IN. (7.62 MM) in width or more than 10 secondary swirl nozzle venturis with total missing material at each venturi more than 0.100 IN. (2.54 MM) in width. Cracks and Missing Material in the Dome Area ** ON A/C NOT FOR ALL					25 cycles continue-in-service limit
B.Inner and outer liners
(1)Outer liner axial cracks					100 cycles
Up to five cracks across more than one panel, and a crack can go across up to five panels in sequence.
(2)Outer liner axial cracks from outer side borescope (for all CFM56-5B engines other than CFM56-5B DAC engines)					25 cycles
Up to 5 cracks across more than one panel, and a crack can go across up to five panels. At least one of the cooling ribs (3, 4, 5, or 6) does not have cracks that extend through to the outer side. Rib 1 is not cracked through.
(3)Outer liner axial cracks from outer side borescope (for CFM56-5B DAC engines):					25 cycles
(a) The crack does not connect to a circumferential crack. (b) The crack goes across cooling rib 3.
(4)Inner liner axial cracks					100 cycles
Up to five cracks across more than one panel, and a crack can go across up to four panels in sequence.
(5)Circumferential cracks					25 cycles
Any number up to three dilution lands in length separated by three non-cracked dilution lands.
(6)Connected cracks (for all CFM56-5B engines other than CFM56-5B DAC engines)					100 cycles
Connection of any axial and circumferential cracks up to maximum limits of paragraphs (1), (2), (3), and (4).
(7)Connected cracks (for CFM56-5B DAC engines):					25 cycles
(a) The connected cracks are not more than the individual axial and circumferential crack limits above. (b) A second axial crack, connected to the pair of connected cracks, is not longer than one panel in length.
(8)Burn through or missing material					100 cycles
There are not more than eight areas that are not more than two times the diameter of a dilution hole. There are not more than two areas that are not more than three times the diameter of a dilution hole. There are not more than one area that is not more than four times the size of a dilution hole. There are not more than three areas in adjacent panels that are aligned axially if they have a separation of a minimum of three dilution lands that are not damaged.
(9)Missing overhangs					25 cycles
Per liner: 17 areas each twice the size of a dilution hole, providing maximum axial alignment of distress is three adjacent panels.
(10)Distortion					25 cycles
Any amount within 0.700 in. (17.78 mm) of original contour.
C.Combustor inner cowl bolts
(1)Missing bolt: maximum of three bolts are missing with four bolts intact between two missing bolts. All other bolts are tight with tack welds intact.					50 cycles for next check, then repeat BSI every 400 cycles.
(2)Bolt tack weld cracked but bolt is not loose: if a maximum of five tack welds are cracked, no more than two consecutive, with four tack welds intact between two cracked tack welds.					25 cycles for first check, 50 cycles for second check, repeat BSI every 100 cycles.
(3)Bolt tack weld is cracked and bolt is loose: if one or more bolts are loose.					5 cycles
7.Fuel Nozzles
A.Fuel nozzles with dislodged wear sleeves or wear sleeves with 4 interrupted weld designs					5 cycles
8.HPT nozzle
A.LE missing material, from cracking or burn-through, up to 0.500 in. (12.70 mm) X 0.500 in. (12.70 mm) per vane. Maximum of 4 vanes per 90 degree arc					25 cycles
B.Concave surfaces of airfoil missing material, from cracking or burn-through, up to 0.750 in. (19.05 mm) diameter per vane					25 cycles
C.Convex side missing panel					25 cycles provided HPT blades are within limits.
D.Inner and outer platforms missing material, from cracking or burn-through, up to 0.500 in. (12.70 mm) diameter per segment					25 cycles
E.TE missing material up to 0.750 in. (19.05 mm) in axial direction					25 cycles
F.Baffle missing material, any amount					10 cycles
9.HPT rotor blade
A.TE cracks in area A less than 0.200 in. (5.08 mm) long					10 cycles
B.TE cracks and convex airfoil cracks within 0.500 in. (12.70 mm) of TE (ten blades maximum ) in area B less than 0.300 in. (7.62 mm) long					25 cycles
C.Radial tip cracks less than 0.350 in. (8.89 mm) long					10 cycles
D.LE cracks in area A less than 0.100 in. (2.54 mm) long					10 cycles
E.Axial nose or gill hole cracks in area B less than 0.050 in. (1.27 mm) long					10 cycles
F.Radial nose or gill hole cracks in area B less than 0.060 in. (1.52 mm) long					10 cycles
G.Radial nose or gill hole cracks in area C less than 0.030 in. (0.76 mm) long					10 cycles
H.Through wall hole in area A and area B (1)Any number of blades if cavity 2 is not exposed on all blades.					25 cycles
J.Through wall hole in area C less than 0.300 in. (7.62 mm) in diameter.					50 cycles
10.HPT shroud and stage 1 Low Pressure Turbine (LPT) nozzle
A.HPT shrouds
(1)Circumferential cracks that are not connected and are more than 1 in. (25.40 mm) long.					25 cycles
(2)Circumferential cracks more than 0.25 in. (6.35 mm) long or closer than 0.25 in. (6.35 mm) from the shroud edge that connect to axial cracks, unless the connected cracks are within the limit for missing material, then missing material limit can be used.					25 cycles
(3)Burn-through of shroud rub land on all HPT shrouds in or less than 0.001 in.2 (0.645 mm2) < Area < 0.005 in.2 (3.226 mm2) is permitted if the shroud does not drop into the flowpath. NOTE: This C-I-S limit is for a reduced interval, repeat inspection.					75 cycles
(4)Burn-through of shroud rub land on all HPT shrouds in or less than 0.005 in.2 (3.226 mm2) < Area < 0.015 in.2 (9.677 mm2) is permitted if the shroud does not drop into the flowpath. NOTE: This C-I-S limit is for a reduced interval, repeat inspection.					25 cycles
(5)Burn-through of shroud rub land on all HPT shrouds when Area > 0.015 in.2 (9.677 mm2) is permitted if the shroud does not drop into the flowpath.					25 cycles
(6)Material loss on split-line forward corners more than 0.250 in. (6.35 mm) in axial direction and 0.080 in. (2.03 mm) in circumferential direction is permitted, if there is no other burn-through on the shroud. NOTE: This C-I-S limit is for a reduced interval, repeat inspection.					400 cycles
(7)Material loss on split-line on areas different than forward and aft corners is permitted if area (A) is above 0.013 in.2 (8.387 mm2) OR distance from original contour in circumferential direction (d) is above 0.080 in. (2.03 mm), if there is no other burn-through on the shroud. NOTE: This C-I-S limit is for a reduced interval, repeat inspection.					400 cycles
(8)Material loss on split-line on areas different than forward and aft corners is permitted if area (A) is above 0.013 in.2 (8.387 mm2) AND distance from original contour in circumferential direction (d) is above 0.080 in. (2.03 mm), if no other burn-through on the shroud. NOTE: This C-I-S limit is for a reduced interval, repeat inspection.					200 cycles
(9)Material loss on split-line on areas different than forward and aft corners is permitted if area (A) is above 0.013 in.2 (8.387 mm2) AND distance from original contour in circumferential direction (d) is above 0.080 in. (2.03 mm) AND when other burn-through with the area over 0.001 in.2 (0.645 mm2) is on the shroud.					25 cycles
B.Stage 1 LPT nozzle
(1)Cracks in all areas up to 1.400 in. (35.56 mm) long provided not more than two adjacent airfoils per segment.					10 cycles
(2)One crack permitted on each airfoil, from LE to TE, if there is no missing material.					100 cycles
(3)Burns, erosion, corrosion and melted metal up to 1.000 in.2 (645.16 mm2) per airfoil and no cracks extending from distressed area if there is no missing material.					5 cycles
(4)Cracks in outer and inner platforms up to 1.000 in. (25.40 mm).					100 cycles
11.LPT Rotor
A.LPT blades (all stages) for: Measurements of airfoil indication on LPT blades (all stages).
(1)Blade pretwist
Stage 1: pretwist gaps such that adjacent interlocks do not touch. Permitted if the faces of the interlocks are not worn.
Stages 2-4 gaps such that adjacent interlocks do not contact each other.					5 cycles
(2)0.080 in. (2.03 mm) maximum deflection over a length ten times longer maximum, only for stage 1 LPT blades distorted LEs, due to overtemperature.					15 cycles
(3)Stages 1, 2, 3 blades
Area E: Any amount of impact damage/rubbing provided there is no missing material or cracks.					5 cycles or 10 hours (whichever comes first)
Other areas: Any amount of impact damage such as bending, nicks and/or dents is allowed provided there is no missing material or cracks exceeding 50% of chord width.					5 cycles or 10 hours (whichever comes first)
(4)Stage 4 blades
Any amount of tip shroud interlock wear allowed.					25 cycles or 50 hours (whichever comes first)
Blades tip shroud protrusion not to exceed 0.040 in. (1.02 mm).					10 cycles or 25 hours (whichever comes first)
Area E:
Any amount of impact damage such as nicks and/or dents is allowed provided there is no missing material or cracks.					5 cycles or 10 hours (whichever comes first)
Other areas:
Any amount of impact damage. One complete airfoil and any number of tip shrouds with associated airfoil tips may be missing provided engine vibration is not excessive.					5 cycles or 10 hours (whichever comes first)
Blade tip shrouds shingled or unlatched provided rotor turns freely and engine vibration is not excessive.					5 cycles or 10 hours in shingled condition. (whichever comes first)
B.Nozzle segments 2 to 4
(1)Three cracks maximum for each nozzle segment if cracks are more than 0.500 in. (12.70 mm) (1/3 of the chord width) and less than 1.000 in. (25.40 mm) (2/3 of the chord width) if the adjacent nozzle segments have no more than two cracks more than 0.500 in. (12.70 mm) (1/3 of the chord width) and less than 1.000 in. (25.40 mm) (2/3 of the chord width).					200 cycles
(2)One crack maximum for each nozzle segment that is more than 1.000 in. (25.40 mm) (2/3 of the chord width) including open airfoil.					200 cycles
(3)One full chord crack on two airfoils for each segment if the adjacent nozzle segments have no more than one airfoil with a full chord crack.					25 cycles
(4)Nicks, dents, tears, missing pieces up to 2.000 in.2 (1290.32 mm2) on nonadjacent vanes provided there are no cracks extending from distressed areas.					10 cycles
(5)Burned areas with missing material or melted.					25 cycles
C.Stage 4 shroud abradable material
(1)Worn, jagged or crushed sealing surface exceeding 50% of the honeycomb height provided sectors of the shroud abradable material are not missing.					10 cycles
12.LPT Casing
A.Forward and aft flanges
(1)One crack connecting two bolt holes without penetrating pressure vessel outer skin					10 cycles
(2)One crack into skin 0.400 in. (10.16 mm) long maximum					10 cycles
B.External surface of the casing
(1)One crack 0.400 in. (10.16 mm) long maximum					10 cycles
C.Cooling air tube and manifold assemblies					10 cycles
(1)One separated circumferential tube
(2)3.000 in. (76.20 mm) cumulative cooling air manifold crack
(3)One separated cooling air tube support
D.Thread ports and bosses
(1)One crack, 0.500 in. (12.70 mm) maximum providing there is no leakage.					10 cycles
13.Turbine frame
A.Forward and aft flanges					10 cycles
(1)One circumferential crack connecting two bolt holes
(2)One crack into skin 0.500 in. (12.70 mm) maximum
B.Engine mounting lug areas airframe attach points only					10 cycles
(1)One crack out of one mount lug bolt hole 0.250 in. (6.35 mm) maximum
(2)Skin crack 0.250 in. (6.35 mm) maximum
C.Threaded parts and bosses					10 cycles
(1)One crack, 0.500 in. (12.70 mm) long providing there is no fluid or air leakage
D.Stud on the aft face of the inner hub
(1)Missing/broken/loose stud(s):
One or two studs					500 hours or 500 cycles (whichever comes first)
Three studs
*If not adjacent to each other					500 hours or 500 cycles (whichever comes first)
*If two non-serviceable studs are adjacent, but the third one is separated from them by two serviceable studs					500 hours or 500 cycles (whichever comes first)
*If not					Replace studs
Four studs or more					Replace studs
E.Thermal insulation blankets					100 cycles
(1)Missing or protruding blankets
F.Other areas					10 cycles
(1)One crack 0.250 in. (6.35 mm) maximum
14.Accessory gearbox
A.Two opposite keylock studs missing, provided there is no leakage at flange					3 cycles or 30 hours (whichever comes first)
B.Oil leakage from AGB/Starter carbon seal (Ref. AMM TASK 79-00-00-210-003).					10 cycles provided seal drain line is disconnected and drain cavity is capped.

[Rev.10 from 2021] 2026.04.01 02:40:46 UTC