Standard Practice Engine, General [CFML]

TASK 70-00-00-910-803-A
Standard Practice Engine, General

1. Reason for the Job
Self explanatory
2. Job Set-up
Subtask 70-00-00-860-052-A

A. Not Applicable

3. Procedure
Subtask 70-00-00-910-054-A

A. Engine information
CFM: Nominates LEAP-1A engine.

Subtask 70-00-00-910-055-A

B. Engine directional references
Clockwise, counterclockwise, clock position and other directional references apply to the engine in a horizontal position, viewed from the rear, and with the accessories section at the bottom. When components or struts are numbered in a circumferential direction the No.1 position is at 12 o'clock, or immediately clockwise from 12 o'clock. The remaining positions increase arithmetically in a clockwise direction.

Subtask 70-00-00-910-056-A

C. Welding repair on engine

Subtask 70-00-00-910-057-A

D. Definition of Terms and Abbreviation

WARNING: WARNINGS CALL ATTENTION TO METHODS, PROCEDURES OR LIMITS WHICH, IF NOT PRECISELY FOLLOWED, POSE A PARTICULAR RISK OF INJURY OR DEATH TO PERSONS.

CAUTION: CAUTIONS CALL ATTENTION TO METHODS AND PROCEDURES WHICH, IF NOT PRECISELY FOLLOWED, POSE A PARTICULAR RISK OF EQUIPMENT DAMAGE.

(1) The following terms are used in the maintenance manual and are defined as follows:

NOTE: Notes call attention to methods which make the job easier, or provide supplementary or explanatory information.

Subtask 70-00-00-910-058-A

E. Defects
The following terms are used to describe/define defects:

TERM	DEFINITION	ASSOCIATED TERMS
Blister	A raised portion of a surface caused by separation of the outer layers of the parent material or of a coating applied to it.	Bubble Flaking Oxide Formation Peeling Scale Slag inclusion (weld).
Brittle	A change in the elasticity or resilience of the parent material usually caused by aging, extreme cold, chemical action, or cold-working.	Cold worked hard (like an old O-ring).
Buckle	A large-scale deformation of the original contour of a part, usually caused by pressure or impact from a foreign object, structural stresses, excessive localized heating, high-pressure differentials, or any combinations of these.	Ballooning Bend Bulge Crease Curl Dent (not to be confused with small-area defect in heavy material) Depression Distortion Elongation Fold Indentation Kink Protrusion (hollow) Rupture (result of excessive buckling) Uneven Warpage Wrinkle.
Burn	A rapid, destructive, oxidizing action, usually caused by higher temperatures than the parent material can withstand. Change in color appearance often indicates this condition.	Burn-out (missing piece) Erosion Corrosion Guttered Heat-check Heat deterioration Hole (burn) Hot spot Overheated Oxidiation.
Burnishing	Smoothing of a metal surface by mechanical action, but without a loss of material. Generally found on plain bearing surface. Surface discoloration is sometimes visible around the outer edges. Normal burnishing from operational service is not detrimental if the coverage approximates the carrying load and there is no evidence of burns.	Rub Wear
Burr	A rough edge or a sharp protrusion on the edge or surface of the parent material.
Chafing	See "Gall" or "Scratch"
Chip	A breaking away of the edge of the parent material, usually caused by heavy impact from a foreign object.	Break Nick (similar to Chip, but no parent material is removed). Notched Spalling (usually a broken-away flat surface).
Corrosion	A mass of small pits which cumulatively create a large, shallow cavity (usually rough in the surface of the parent material).	Pit
Crack	A parting or discontinuity in the parent material.	Break Cold shut (castings) Crater (castings) Fatigue damage Fissure Fracture Lap (forgings) Rupture Seam Separation Slit Tear
Crazing	A mesh of minute hairline cracks found in glazed or baked-on coated surfaces, generally caused by temperature change or by deformation of parent metal. Cracks do not penetrate into parent metal.
Creep	Gradual continuous distortion or plastic flow under constant stress.
Deformation	Any alteration or change of shape, dimension or configuration resulting from stress or damage.	Bend Creep Distortion
Dent	A completely smooth surface depression caused by pressure or impact from a smooth, rounded foreign object. The parent material is displaced, but none is separated.	Peen
Deviation	Any condition that causes a part to differ from the manufacturer's blueprint.	Damage Defect Flaw Imperfection Irregularity
Discontinuity	An interruption in the normal physical structure or configuration of a part.	Crack Seam Cold shut Lap
Distortion	Any twisting, bending or permanent strain that results in misalignment or change of shape.	Bend Deformation
Erosion	Gradual wearing away of a surface caused by a fluid (gas or liquid) flowing over the surface. Wear is generally caused by fine particles of foreign material entrained in hot engine gases flowing at a high velocity.
Fatigue	The progressive fracture of a material under cyclic stress loading.	Crystallization Fretting Flaking
Flaking	See " Spalling"
Fretting	Wearing away by low-amplitude rubbing against another metal (generally associated with press fit or close fitting parts).	Wear Galling
Galling	A defect caused by the movement of 2 surfaces in contact with each other. In most cases, an accumulation of foreign material is deposited on the parent material.	Pickup
Gouge	A wide, rough scratch or group of scratches, usually with one or more sharply incised corners, and frequently accompanied by deformation or removal of parent material.
Groove	A long, narrow, continuous depression caused by pressure of a moving surface in contact with the parent material.	If depression is shallow and smooth, see "Wear"; if depression is sharp, see "Scratch".
High spots	Local distortions	Blister Buckle Bubble Out-of-round
High metal	Displaced metal adjacent to a defect such as a scratch, nick or gouge, which is raised above the surrounding.	Burr
Imbalance	The state of being out-of-balance. Unequal distribution of weight about the axis of rotation, which usually results in vibration.
Inclusion	Foreign material embedded in metal during solidification, or formed by subsequent reaction of the solid metal.
Indication	The visible evidence that a material defect exists, even though the defect itself may not be visible to the naked eye.
Looseness	Abnormal movement of a part, or insufficient securing of a part.	Backed out Excessive play Excessive back-lash Insufficient torque Shaky Sloppy Unbottomed Unpinned Unwired
Misalignment	A mismatching or malformation of any part which either prevents perfect assembly or results in faulty operation and/or ultimate failure.	Eccentric Out-of-round Out-of-square Mismatched Unmatched
Nick	A surface impression with sharp corners or bottom, usually caused by pressure or impact from a sharp-edged object. The parent material is displaced, but usually none is separated.	Chip Dent Notch
No apparent Depth	Term used to describe surface defects that can be seen but not felt with fingernail or scriberpoint.
Noise	An abnormal sound involving moving parts, usually an increase in volume or a change of pitch.	Bumps (sound) Chatters Clicks Grates (usually gears) Grinds Hums Rattles Rubs Scrapes (sound) Screeches Thumps Whistles
Obstruction	Prevention of free flow of a fluid (air, oil, fuel, water) because of foreign material in the flowpath or malformation of the part.	Clogged Contaminated Plugged Restricted
Oil-canning (Snapping action)	Snapping or popping displacement of sheet metal when restrained at its edges like a diaphragm, wall, or bottom of an oil can.	Buckling
Parent Metal	All material in a single part except the weld, braze filler, or heat-affected zone (within 1/8 inch (3.175 mm) of the fusion line).
Pickup	Transfer of one material into or onto the surface of another in contact with it, usually as a result of friction-heating.	Burr Gall Imbedment Inclusion Pile-up Protrusion Metallization
Pinched	Distortion of one or more surfaces of the parent material, caused by pressure.	Bound Bound Compressed Flattened Seized Smashed (without separation into pieces) Squashed Squeezed
Pit	A minute depression or cavity having no sharp, high-stress corners in the surface of the material. Pits are usually caused by chemical reaction (rusting, chemical corrosion).	Corrosion Crater Electrolytic cavity Inclusion Perforation Pinholes Pock-marked
Porosity	Areas containing numerous pits or pinholes.	Pit Pinholes
Rub	A surface depression or displacement caused by two surfaces moving while in contact with each other.	If impression is shallow and smooth, see "Wear". If impression is sharp, see "Scratch".
Scale	A layer of metallic oxides formed by chemical action of oxygen on the exposed surface of the metal, usually while hot.	Burn
Scratch	A long, narrow, sharp-cornered impression caused by the movement of a sharp object across the surface of the parent material.	Abrasion Chafe Furrow Groove Score
Seizure	A welding or binding of faces which prevent further movement.	Bound up Frozen Tight Wedged Welded (without external heating).
Shingling	A condition when one fan blade mid-span shroud moves over the other (usually when something hits the fan). It is called shingled when fan blade mid-span shroud stays overlapped on the other. The condition can also occur to the blade tip shrouds on the LPT rotor (Stg. 3 and 4). The condition on the LPT is usually caused by a loss of pre-twist, too much radial movement, etc.	Wedged Bound up Shingled
Spalling	Cracking off or flaking off of small particles of metal from the surface, usually in thin layers or localized spots.	Flaking Fretting Galling
Tear	A physical separation by tearing, pulpulling apart by force, or wrenching of metal.
Unbalance	The act of putting a balanced component out of balance. Usually "imbalance" is meant.
Varnish film	A hard surface-film of partially carbonized hydrocarbon, such as oil, which is built up when the part is heated to or above the breakdown-point of the fluid.	Banded Discolored Oxidized Stained
Wear	Relatively slow removal of parent material in the process of operation (not always visible to the naked eye).	Abrasion Attrition Brinnelled Chafed Chattering Erosion Fraying Fretting Friction Galling Glazing Groove Interference Oxidation Roughness Rubbed Scarfed Scuffed Uneven Weak.

[Rev.10 from 2021] 2026.04.01 02:20:47 UTC