Provides information on all procedures of a special nature and on general procedures for the disassembly, cleaning, inspection, repair, modification, reassembly, and testing of engines
Non-destructive inspection and testing equipment
Magnetic particle testing
Liquid penetrant inspection
Ultrasonic inspection
Radiography
Top Overhaul
An overhaul of those parts on top of the crankcase, without completely dismantling the engine
Major Overhaul
The complete reconditioning of the powerplant, where the crankcase is disassembled
Major Repairs
Not generally a major overhaul, but can be performed by a certified powerplant-rated technician
Receiving the Engine
1. Receivinginspection
2. Inventory
3. Organization of Engine Records
Extensive records must be kept as the engine progresses through the overhaul process
The repair station should maintain a complete record of all repair operations and inspections performed on each engine or component overhauled
Reciprocating Overhaul
A complete overhaul process includes the following ten steps: receiving inspection; disassembly; visual inspection; cleaning; structural inspection; non-destructive testing (NDT) inspection; dimensional inspection; repair and replacement; reassembly; and testing and break in.
Receiving Inspection
The receiving inspection consists of determining the general condition of the total engine as received, along with an inventory of the engine’s components.
Inspection
The general condition of the engine should be carefully noted on the receiving report. If the engine has been in a crash, fire, or other situation where damage may have been caused, such conditions have to be recorded.
Inventory
It is essential that every part be accounted for, because an owner may not be aware that certain parts or accessories were removed before the engine was delivered to the overhaul facility.
Engines are designed and built to provide many years of service. For an engine to remain in airworthy condition, it should be operated in accordance with the recommendations of the manufacturer and cared for with sound inspection and maintenance practices.
Visualinspection
Needed to determine the current condition of the engine and its components
Abrasion
An area of roughened scratches or marks usually caused by foreign matter between moving parts or surfaces
Brinelling
One or more indentations on bearing races, usually caused by high static loads or application of force during installation or removal
Burning
Surface damage due to excessive heat, usually caused by improper fit, defective lubrication, or over-temperature operation
Burnishing
Polishing of one surface by sliding contact with a smooth, harder surface, usually no displacement nor removal of metal
Burr
A sharp or roughened projection of metal usually resulting from machine processing
Chafing
A condition caused by a rubbing action between two parts under light pressure that results in wear
Chipping
Breaking away of pieces of material, usually caused by excessive stress concentration or careless handling
Corrosion
Loss of metal by a chemical or electrochemical action, the corrosion products are easily removed by mechanical means
Crack
A partial separation of material usually caused by vibration, overloading, internal stresses, defective assembly, or fatigue
Cut
Loss of metal, usually to an appreciable depth over a relatively long and narrow area, by mechanical means
Dent
A small, rounded depression in a surface usually caused by the part being struck with a rounded object
Erosion
Loss of metal from the surface by mechanical action of foreign objects, such as grit or fine sand
Flaking
The breaking loose of small pieces of metal or coated surfaces, usually caused by defective plating or excessive loading
Fretting
A condition of surface erosion caused by minute movement between two parts usually clamped together with considerable unit pressure
Galling
A severe condition of chafing or fretting in which a transfer of metal from one part to another occurs, usually caused by a slight movement of mated parts having limited relative motion and under high loads
Gouging
A furrowing condition in which a displacement of metal has occurred, usually caused by a piece of metal, or foreign material, between close moving parts
Grooving
A recess, or channel, with rounded and smooth edges usually caused by faulty alignment of parts
Inclusion
Presence of foreign or extraneous material entirely within a portion of metal, introduced during the manufacture of rod, bar, or tubing by rolling or forging
Nick
A sharp-sided gouge or depression with a V-shaped bottom, generally the result of careless handling of tools and parts
Peening
A series of blunt depressions in a surface
Pick up or scuffing
A buildup or rolling of metal from one area to another, usually caused by insufficient lubrication, clearances, or foreign matter
Pitting
Small hollows of irregular shape in the surface, usually caused by corrosion or minute mechanical chipping of surfaces
Scoring
A series of deep scratches caused by foreign particles between moving parts or careless assembly or disassembly techniques
Scratches
Shallow, thin lines or marks, varying in degree of depth and width, caused by presence of fine foreign particles during operation or contact with other parts during handling
Stain
A change in color, locally, causing a noticeably different appearance from the surrounding area
Upsetting
A displacement of material beyond the normal contour or surface (a local bulge or bump), usually indicates no metal loss