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Standard

Fire Resistant Phosphate Ester Hydraulic Fluid for Aircraft

2021-07-20

WIP

AS1241E

This document establishes the requirements for physical and chemical properties and the minimum tests to evaluate suitability of phosphate ester hydraulic fluids for use in aircraft systems where fire resistance is required. Additional tests may be specified by the qualifying agency to demonstrate compliance with their specific requirements. The "qualifying agency" will be defined herein to be the airframe manufacturer submitting certification approval for use of the fluid in a specific model airplane. Fluids meeting the requirements of this specification may be approved by a qualifying agency for use on specific airplane models. Data used to show compliance to this specification can be used by the qualifying agency to show compliance to the applicable regulations for the appropriate certifying authority; e.g., FAA, EASA, etc.

Standard

Methods, Locations and Criteria for System Sampling and Measuring the Solid Particle Contamination of Hydraulic Fluids

2021-05-06

CURRENT

ARP5376C

This Aerospace Recommended Practice (ARP) provides: Recommended methods for cleaning sample bottles, when used, and the solvents to be applied and how these solvents should be prepared. Recommendations for three measuring methods for determining the level of solid particle contamination of hydraulic fluids used in aerospace hydraulics. Recommendations for the selection of the sampling point, sampling method, and the sampling frequency.

Standard

Degradation Limits of MIL-PRF-5606, MIL-PRF-83282, and MIL-PRF-87257 Hydraulic Fluids Used in Hydraulic Test Stands

2020-10-14

CURRENT

AIR810E

This SAE Aerospace Information Report (AIR) presents data on normally accepted changes in physical properties and contamination levels for MIL-PRF-5606, MIL-PRF-83282, and MIL-PRF-87257 hydraulic fluids used in hydraulic test stands. This information is of importance to all users of hydraulic test stands to assure the performance data obtained on these test stands for specific components will not be adversely affected by excessive changes in fluid properties or contamination levels.

Standard

Filter Element Cleaning Methods

2020-10-09

CURRENT

AIR787B

This SAE Aerospace Information Report (AIR) provides technical information to assist the development of specific cleaning methods for those filter elements which are designated as "cleanable" and cannot be cleaned by simple and obvious procedures.

Standard

Importance of Physical and Chemical Properties of Aircraft Hydraulic Fluids

2019-10-02

CURRENT

AIR81E

This document discusses the relative merits of the physical and chemical properties of hydraulic fluids in relation to the aerospace hydraulic system design, and the related materials compatibility. The discussion in this report applies both to hydrocarbon and phosphate ester based aircraft hydraulic fluids. In some cases, numerical limits are suggested, but, in general, the significance and effect of a property is noted qualitatively.

Standard

Aerospace Fluid Power - Hydraulic Filter Elements - Method for Evaluating Dynamic Efficiency With Cyclic Flow

2019-07-15

WIP

ARP4205A

This SAE Aerospace Recommended Practice (ARP) describes a method for evaluating the performance of filter elements designed for Aerospace hydraulic systems. The performance is measured and reported in terms of filtration ratios and stabilized contamination level while testing with cyclic flow.

Standard

Filter Patch Testing Procedures for Aerospace Hydraulic Non-Rotating Equipment

2019-07-15

CURRENT

ARP1302A

This SAE Aerospace Recommended Practice (ARP) provides a procedure for obtaining filter patch test samples from the following types of aerospace non-rotating hydraulic equipment: Mechanical/Hydraulic Units Electro/Hydraulic Units Pneumatic/Hydraulic Units

Standard

Aerospace Hydraulic Fluids Physical Properties

2018-08-16

CURRENT

AIR1362D

This SAE Aerospace Information Report (AIR) presents data on hydraulic fluids which are of interest to detail designers of hydraulic systems and components for aerospace flight vehicles. The data pertains to fluids conforming to the following specifications: MIL-PRF-5606 MIL-H-8446 MIL-PRF-27601 (canceled) MIL-PRF-27601 has been canceled without replacement and the data presented herein is for information purposes only. MIL-PRF-83282 MIL-H-53119 MIL-PRF-87257 AS1241 Type IV, Classes 1 and 2, and Type V

Standard

Aerospace - Evaluation of Particulate Contamination in Hydraulic Fluid - Membrane Procedure

2018-08-13

CURRENT

ARP4285A

This SAE Aerospace Recommended Practice (ARP) establishes a method for evaluating the particulate matter extracted from the working fluid of a hydraulic system or component using a membrane. The amount of particulate matter deposited on the membrane due to filtering a given quantity of fluid is visually compared against a standard membrane in order to provide an indication of the cleanliness level of the fluid.

Standard

Aerospace Hydraulic Fluids Physical Properties

2016-11-01

HISTORICAL

AIR1362C

This SAE Aerospace Information Report (AIR) presents data on hydraulic fluids which are of interest to detail designers of hydraulic systems and components for aerospace flight vehicles. The data pertains to fluids conforming to the following specifications: MIL-PRF-5606 MIL-H-8446 MIL-PRF-27601 (canceled) MIL-PRF-27601 has been canceled without replacement and the data presented herein is for information purposes only. MIL-PRF-83282 MIL-H-53119 MIL-PRF-87257 AS1241 Type IV, Classes 1 and 2, and Type V

Standard

Fire Resistant Phosphate Ester Hydraulic Fluid for Aircraft

2016-09-16

CURRENT

AS1241D

This document establishes the requirements for physical and chemical properties and the minimum tests to evaluate suitability of phosphate ester hydraulic fluids for use in aircraft systems where fire resistance is required. Additional tests may be specified by the qualifying agency to demonstrate compliance with their specific requirements. The "qualifying agency" will be defined herein to be the airframe manufacturer submitting certification approval for use of the fluid in a specific model airplane. Fluids meeting the requirements of this specification may be approved by a qualifying agency for use on specific airplane models. Data used to show compliance to this specification can be used by the qualifying agency to show compliance to the applicable regulations for the appropriate certifying authority; e.g., FAA, EASA, etc.

Standard

Aerospace Microscopic Sizing and Counting of Particulate Contamination for Fluid Power Systems

2016-06-09

CURRENT

ARP598D

This SAE Aerospace Recommended Practice (ARP) defines the materials, apparatus and procedure for sizing and counting of particulate contamination, 5 μm or greater, in hydraulic fluid samples by membrane filtration iwth microscopic counting. It is capable of counting particulate matter in samples withdrawn from fluid power systems as identified by the 12 classes of SAE AS 4059 or NAS 1638 and projected beyond these for the five standard ranges specified and can thus serve as the primary document to determine acceptability. It is also capable of revealing but not measuring evidence of abnormal amount of water, other fluids, fine particulate and other materials, especially fibers and metals. It is applicable to all military, civil, space vehicles and test equipment.

Standard

Importance of Physical and Chemical Properties of Aircraft Hydraulic Fluids

2016-04-20

HISTORICAL

AIR81D

This document discusses the relative merits of the physical and chemical properties of hydraulic fluids in relation to the aerospace hydraulic system design, and the related materials compatibility. The discussion in this report applies both to hydrocarbon and phosphate ester based aircraft hydraulic fluids. In some cases, numerical limits are suggested, but, in general, the significance and effect of a property is noted qualitatively.

Standard

Evaluating Effectiveness of Filter Element Cleaning Methods

2014-06-03

CURRENT

ARP725B

This SAE Aerospace Recommended Practice (ARP) presents a procedure for evaluating cleaning methods with respect to contaminant removal and element degradation particularly for metallic filter elements. A procedure for checking durability of cleaning equipment and a referee cleaning method are also included. It is applicable only to the evaluation of cleaning methods proposed for removal of service dirt and not for built-in dirt, liquid oxygen (LOX) cleaning, etc. Supporting information for use with the ARP is also included.

Standard

Sensitization and Corrosion in Stainless Steel Filters

2014-02-06

CURRENT

AIR844B

This document reviews briefly the subject of woven metal screens. Conditions that can promote damaging corrosion in stainless steel filter screens are discussed and recommendations are listed for minimizing corrosion damage. This is a general document only; for specific applications it is suggested that the reader refer to the technical literature, and selected references listed below.

Standard

Evaluating Effectiveness of Filter Element Cleaning Methods

2013-10-08

HISTORICAL

ARP725A

This SAE Aerospace Recommended Practice (ARP) presents a procedure for evaluating cleaning methods with respect to contaminant removal and element degradation particularly for metallic filter elements. A procedure for checking durability of cleaning equipment and a referee cleaning method are also included. It is applicable only to the evaluation of cleaning methods proposed for removal of service dirt and not for built-in dirt, liquid oxygen (LOX) cleaning, etc. Supporting information for use with the ARP is also included.

Standard

Filter Element Cleaning Methods

2013-10-08

HISTORICAL

AIR787A

This SAE Aerospace Information Report (AIR) provides technical information to assist the development of specific cleaning methods for filter elements. Consideration is limited to filter elements which are designated as "cleanable" (not "disposable"), but which cannot be cleaned by simple and obvious procedures. Cleaning methods developed according to this report should be evaluated by the methods of ARP725. Satisfactory cleaning methods can be developed for most "cleanable" filter elements. Technical or economic feasibility of the cleaning method may be limited, however, by incompatibility of filter-element construction materials, by mechanical weakness or lack of corrosion resistance to withstand repeated or continued cleaning, or by the presence of unusually tenacious contamination. These factors must be considered when selecting approaches to the development of specific methods.

Standard

Aerospace - Chlorinated Solvent Contamination of MIL-H-5606/MIL-H-83282 Vehicle Hydraulic Systems

2013-06-18

CURRENT

AIR4713A

Although there is controversy regarding the chemical form of chlorine and its relation to harmful effects in the hydraulic fluid (i.e., chloride ions versus organic chloro-compounds versus total chlorine in all forms), it is generally agreed that total chlorine content should be measured and controlled. In the near future, the ban on the manufacture of chlorinated solvents, out of concern for depletion of the ozone layer, may in itself diminish or eliminate chlorine contamination related aircraft malfunctions. It is generally accepted that hydraulic fluid contamination should be held to a minimum under all conditions. The benefits of low contamination levels are improved performance, lower maintenance due to lower wear, corrosion and erosion, longer fluid life, longer component life, etc. Contaminants can be classified into two general types: those that are insoluble and those that are soluble in the hydraulic fluid.

Standard

Degradation Limits of Hydrocarbon-Based Hydraulic Fluids, MIL-PRF-5606, MIL-PRF-83282, and MIL-PRF-87257 Used in Hydraulic Test Stands

2013-04-22

HISTORICAL

AIR810D

This SAE Aerospace Information Report (AIR) presents data on normally accepted changes in physical properties and contamination levels for military hydraulic fluids used in hydraulic test stands. This information is of importance to all users of hydraulic test stands to assure the performance data obtained on these test stands for specific components will not be adversely affected by excessive changes in fluid properties or contamination levels. The data pertains to fluids conforming to specifications MIL-PRF-5606, MIL-PRF-83282, and MIL-PRF-87257. The guidelines incorporated in the AIR are the general consensus values of knowledgeable professionals. However, the experience and judgment of engineers and operators responsible for the equipment must be relied upon to determine when the hydraulic fluid is to be replaced.

Standard

Secondary Filters for Fluid System Reliability

2012-09-24

CURRENT

AIR4057B

This SAE Aerospace Information Report (AIR) discusses the design choices and engineering trade-offs available to the system designer in the efficient selection and application of Last-Chance filters in contrast to main or primary system filters.