ATA 20    Standard Practices & material information

1 - Sealants, types and curing-times.  UPDATED !

2 - All BMS- numbers with description.  

3 - Technical terms to describe inspection-findings.

4 - List of P/N versus spec & description BMS/GREASE etc.

5 - Complete Aeroshell book available for reference only. 

6 - Shell  product specification sheets overview  (fuel - oil - grease - hydraulics).

7 - BP Turbo Oil  lubricants brochures (oil).

8 - Cross reference BMS- / MIL-  spec to productname.  Additions Welcome!!

9 - BINAIRY - HEXADECIMAL - DECIMAL - OCTAL converter. 

10 - All info on PR 1776 Class B sealant.  

11 - Oversize press fit type lube fittings.

12 - Dow Corning RTV adhesive / sealant product information sheet.

13 - Zip-Chem product cross reference overview. 

        3-Technical terms :   (click on term to see picture if available)

Arced:

Visible effects (burn spots, fused metal) of an undesired electrical discharge between two electrical connections.

Binding:

Restricted movement such as tightened or sticking condition resulting from high or low temperature, foreign object jammed in mechanism, etc.  

Burrs:

A rough edge or a sharp projection on the edge or surface of the parent material.

Chafed:

Frictional wear damage usually caused by two parts rubbing together with limited motion.

Checked:

Surface cracks usually caused by heat.

Chipped:

A breaking away of the edge corner or surface of the parent material usually caused by heavy impact (not flaking).

Circuit - Grounded:

Undesired current path to ground (common).

Circuit - Open:

Incomplete electrical circuit due to separation at or between electrical connection points.

Circuit - Shorted:

Undesired current path between leads or circuits that normally are at a different potential.

Corroded:

Gradual destruction of the parent material by chemical action. Often evidenced by oxide build-up on the surface of the parent material.

Crossed:

Material damage to parts (as in the case of crossed threads) or part rendered inoperative (as in the case of crossed wires) as a result of improper assembly.

Eccentric:

Part(s) wherein the intended common center is displaced significantly.

Eroded:

Carry away of material by flow of fluids or gases, accelerated by heat or grit.

Flattened out:

Permanent deformation beyond tolerance limits usually caused by compression.

Frayed:

Worn into shreds by rubbing action.

Fused:

Joining together of two materials usually caused by heat, friction, or current flow.

Glazed:

Undesirable development of a hard, glossy surface due to rubbing action, heat or varnish.

Indications:

Cracks, inclusions, fractures etc. not visible without fluorescent or magnetic penetrants.

Melted:

Deformation from the o-riginal configuration due to heat, friction or pres-sure as with melted bear-ings or insulation.

Mis-matched:

Improper association of two or more parts.

Mis-aligned:

Improper installation of a part resulting in damage to the installed part or to associated parts.

Plugged:

Pipe, hoses, tubing, channeling, internal passage etc. which are totally or partially blocked.

Rough:

Usually applies to operation as opposed to surface finish; i.e. a condition of bearings (which cannot be disassembled further) where during the spin test the rotation is rough.

Rubbed:

To move with pressure or friction against another part such as compressor rub.

Rust:

Sometimes written down  when corrosion is found. Applies only to some specific persons. If "rust" is found, no aircraft will ever leave the hangar.

Seized:

Parts bound together because of expansion or contraction due to high or low temperature, foreign object jammed in mechanism, etc.

Streched:

Enlargement of a part as a result of exposure to operating conditions.+

Stripped:

A condition usually associated with threads or insulation. Involves removal of material (threads) by force.

Worn excessively:

Material of part consumed as a result of exposure to operation or usage, beyond the limits given by the manufacturer.

        8 - Cross reference table BMS/MIL/name:      (UNCONTROLLED DATA !)

 

Specification Ref Number	Product Name	Product Name	Product Name
BMS 3-11	Skydrol LD 4
BMS 3-23	Dinal AV 58-2	LPS - 3	AV 8
BMS 3-27	Mastinox		AV 30
BMS 3-29			AV 30
BMS 3-26			AV 25
BMS 3-33	Aeroshell Grease 33	-	-
BMS 3 - 24	Shell Grease 16	-	-
BMS 3 - 28	AntiSeize
BMS 3-32	SSF
BMS 3-32 type II	LGF	klm3804065
BMS 3-33	Grease 33
BMS 5 - 26	PRC 1422	-	-
DC-33	Dow Corning 33	5565450 - 28	-
MI L- L - 7870	Shell Fluid 3	-	Esso Instrument Oil
MIL - G - 21164	Shell Grease 17	-	NYCO 73BS
MIL - G - 23827	Shell Grease 7	Mobil Grease 27	-
MIL - G - 25760	Shell Grease 16	-	-
MIL - G -81322	Shell Grease 22	Mobil Grease 28	-
MIL - G -47113	340 Heat sink
MIL - G -4343	55 pasta
C-11796	Compound 5
MIL - H - 5606	Shell Fluid 41	Mobil Aero HFE	Esso Invarol FJ1
MIL - L - 6085	Shell Fluid 12	-	-
MIL - L - 7808	Shell Oil 390	Castrol 325	MS4 or Rhodorsil B431
MIL - L -8937	Molykote G Rapid	-	-
MIL - M - 7866	Sundstrand 730651	Sundstrand 688272	Molykote GN Plus
MIL-L-23699	Mobil Jet II	Esso 2380
VV - P - 236	Shell Jelly PX-7	Vaseline BL	NYCO 65
Mil-PRF-27617 t ype 1	KRYTOX240AZ	MIL-G_27617	D00173
MIL-L-23398	Molykote 231R	D231R (dow corning)

        11-Oversize press fit type lube fittings.

When a lubrication fitting is blown out or lost, you can install a new one. But sometimes the lube hole is worn out. Then you can install an oversized lube fitting, but you need to rework the fitting to make it fit.

When there is no time to repair the fitting, you can lubricate the part with a special lube adapter p/n B411. 

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