PAFI-MTP-002 RevB - Contract.pdf

ii

Rev: B

Date: February 15, 2026

PAFI-MTP-002 Rev B

FAA Piston Aviation Fuels Initiative (PAFI)

Materials Compatibility Test Plan

Federal Aviation Administration William J. Hughes Technical Center for Advanced Aerospace Aviation Research Division Atlantic City International Airport New Jersey 08405 ii

Contents

1 Introduction

2 Scope

2.1. Provisos

3 Objectives

4 PAFI materials test plan

5 Applicable MIL, FAA, SAE & ASTM requirements

5.1. Military handbooks & standards

5.2. FAA advisory circulars & orders

5.3. Federal test methods

5.4. SAE standards

5.5. ASTM guidance & practices

6 Description of test articles

6.1. MIL-DTL-6000 hose – aircraft hose

6.2. MIL-DTL-5593 hose – aircraft hose

6.3. Fuel bladders AKA fuel cells

6.4. Polysulfide sealants and Buna-N topcoat testing

6.5. Additional materials; nitrile, fluorosilicone, and fluorocarbon O-rings

6.6. Paint test

6.7. Fabric test

6.8. Distribution hoses

6.9. Composite resins, adhesives, and fabric

6.10. Distribution filters and water separators

6.11. Vendor supplied materials

6.12. Wing fuel tanks

6.13. AMS-G-6032 gasoline and oil resistance grease

7 Conformity iii

7.1. Test fuels

7.2. Samples

7.3. Specimens

8 Safety procedures

8.1. Sample fill (reference ASTM D4057, Section 5.2)

8.2. Static charge (reference ASTM D4057)

8.2.1. Grounding (D4057-12, Section 5.4.1)

8.2.2. Personal attire (D4057, Section 4.5.2)

8.3. Vapor hazards

8.4. Personal protective equipment

8.5. Hydrostatic testing equipment

9 Pre-test requirements

9.1. Specimen identification

9.2. Pre-exposure baseline data

9.3. Pre-exposure photographs

9.4. Laboratory notebook

10 Test facility & equipment

10.1. Temperature controlled areas

10.1.1. Elevated temperature-controlled areas – ovens

10.2. Access controlled area

10.2.1. Access control

10.2.2. Controlled access space

10.3. Tensiometer with extensometers

10.4. Calibrated / validated laboratory measuring equipment

10.5. Sample jars

10.6. Hose stand rig

10.7. ASTM D381 air jet evaporator

10.8. Muffle furnace

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10.9. Bladder (fuel cell) exposure rigs

10.9.1. Simulated stand rig

10.10. Flow sheet manufacture

10.11. ASTM D395 compression blocks

10.12. Industry standard fabric test frames

10.13. Hydrostatic testing equipment

10.14. Composite manufacturing equipment

10.15. Glass transition measurement equipment

10.16. Facility for distribution filter systems

10.17. Centrifuge

10.18. Shaker table

11 Test witnessing

11.1. FAA

12 Test procedure – Task 1, MIL-DTL-6000 and MIL-DTL-5593 hose

12.1. Hose property testing

12.1.1. Materials

12.1.2. Specimen preparation

12.1.3. Exposure

12.1.4. Post exposure measurements

12.1.5. Calculations

12.2. Hose internal soak testing

12.2.1. Materials

12.2.2. Specimen preparation

12.2.3. Exposure

12.2.4. Post exposure measurements

12.2.5. Calculations

13 Test procedure – Task 2 bladder testing per TSO-C80

13.1. General materials

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13.2. Simulated stand test

13.2.1. Test specific materials

13.2.2. Specimen preparation

13.2.3. Exposure

13.2.4. Post test measurements

13.2.5. Calculations

13.3. Volume swell

13.3.1. Test specific materials

13.3.2. Specimen Preparation

13.3.3. Exposure

13.3.4. Post test measurements

13.3.5. Calculations

14 Test procedure – Task 3 polysulfide tank sealants and Buna-N topcoat testing

14.1. Materials

14.2. Physical properties changes

14.2.1. Specimen preparation

14.2.2. Exposure

14.2.3. Post test measurements

14.2.4. Volume change

14.2.5. Tensile/elongation

14.2.6. Hardness

14.2.7. Calculations

14.2.8. Volume change

14.2.9. Tensile/elongation change

14.2.10. Hardness change

14.3. Peel strength testing (sealants 1-7, 9)

14.3.1. Specimen preparation

14.3.2. Exposure

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14.3.3. Class A and B sealants (Sealants 1-7 and 9, Appendix D)

14.3.4. Post test measurements

14.3.5. Calculations

14.4. Buna-N topcoat peel strength (sealant 10)

14.4.1. Specimen preparation

14.4.2. Exposure

14.4.3. Post test measurements

14.4.4. Calculations

14.5. Buna-N topcoat non-volatile content

14.5.1. Specimen preparation

14.5.2. Exposure

14.5.3. Post test measurements

14.5.4. Calculations

15 Test procedure – Task 4 additional elastomer testing

15.1. Compression set

15.1.1. Materials

15.1.2. Specimen preparation

15.1.3. Exposure testing

15.1.4. Post test measurements

15.1.5. Calculations

15.2. Tensile/elongation and hardness

15.2.1. Materials

15.2.2. Specimen preparation

15.2.3. Exposure testing

15.2.4. Post exposure measurements

15.2.5. Calculations

16 Test procedure – Task 5 paint staining and adhesion testing

16.1. Staining and adhesion tests

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16.1.1. Materials

16.1.2. Specimen preparation

16.2. Adhesion exposure testing

16.2.1. Post exposure measurements

16.2.2. Calculations

16.3. Paint staining exposure testing

16.3.1. Post exposure measurements

16.3.2. Calculations

17 Test procedure – Task 6 fabric testing

17.1. Fabric sample construction

17.1.1. Materials

17.1.2. Specimen preparation

17.2. Test execution

17.2.1. Materials

17.2.2. Specimen preparation

17.2.3. Exposure

17.2.4. Post exposure measurements

17.2.5. Calculations

18 Test procedure – Task 7 distribution hose testing

18.1. Physical properties and adhesion

18.1.1. Materials

18.1.2. Specimen preparation

18.1.3. Physical properties (density, volume, and hardness)

18.1.4. Inner liner adhesion testing

18.1.5. Exposure

18.1.6. Post exposure measurements

18.1.7. Calculations

18.2. 16 week static exposure and proof pressure testing viii

18.2.1. Materials

18.2.2. Specimen preparation

18.2.3. Exposure

18.2.4. Post exposure measurements

18.2.5. Visual inspections

18.2.6. Perform hydrostatic proof pressure testing

19 Test procedure – Task 8 composite testing

19.1. Composite resin screening test

19.1.1. Materials

19.1.2. Specimen preparation

19.1.3. Exposure

19.1.4. Post exposure measurements

19.2. Properties testing – finished composites

19.2.1. Materials

19.2.2. Specimen preparation

19.2.3. Test panels lay-up

19.2.4. Laminating resin coupon construction

19.2.5. Prepreg coupon construction

19.2.6. Adhesive joint coupon construction

19.2.7. Surface preparation

19.2.8. Adhesive preparation

19.2.9. Apply adhesive

19.2.10. Cutting laminates into specimens

19.2.11. Labeling specimens

19.2.12. Adding bonded tabs to specimens

19.2.13. Traveler coupons

19.2.14. Rectangular tensile coupons

19.2.15. Short beam cantilever specimens

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19.2.16. V-notch shear specimens

19.2.17. Adhesive joint samples

19.2.18. Pre-exposure measurements

19.2.19. Dimensions

19.2.20. Density

19.2.21. Hardness

19.2.22. Photographic/visual documentation

19.2.23. Tensile, strain, and modulus

19.2.24. Calculating test results

19.2.25. Short beam cantilever

19.2.26. Calculating test results

19.2.27. V-notch shear strength

19.2.28. Calculating test results

19.2.29. Adhesion strength (lap shear)

19.3. Exposure

19.4. Post test exposure

20 Distribution filter, coalescer, & tank coatings

20.1. General materials

20.2. Pleated filter test

20.2.1. Test specific materials

20.2.2. Specimen preparation

20.2.3. Exposure

20.2.4. Post test measurements

20.2.5. Calculations

20.3. Water coalescer test

20.3.1. Test specific materials

20.3.2. Specimen preparation

20.3.3. Exposure

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20.3.4. Post test measurements

20.3.5. Calculations

20.4. Water reaction testing

20.5. Interfacial tension (surface tension)

20.5.1. Calculations

20.6. Material migration by vacuum filtration

20.6.1. Calculations

20.7. Distribution tank coatings

20.7.1. Test specific materials

20.7.2. Specimen preparation

20.7.3. Exposure

20.7.4. Post test measurements

20.7.5. Calculations

21 Vendor supplied materials

21.1. General materials

21.2. Flat stock

21.3. Tensile/elongation, hardness, density, and volume

21.3.1. Materials

21.3.2. Specimen preparation

21.3.3. Exposure testing

21.3.4. Post exposure measurements

21.3.5. Calculations

21.4. Shaped specimens

21.4.1. Materials

21.4.2. Specimen preparation

21.4.3. Exposure testing

21.4.4. Post exposure measurements

21.4.5. Calculations

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22 Manufacturer controlled wing test

22.1. Test specific materials

22.2. Specimen preparation

22.3. Exposure

22.4. Post test measurements

23 Grease resistance testing

23.1. Grease solubility

23.1.1. Materials

23.1.2. Specimen preparation

23.1.3. Post exposure measurements

23.1.4. Calculations

23.2. Grease condition

23.2.1. Materials

23.2.2. Specimen preparation

23.2.3. Exposure testing

23.2.4. Post exposure measurements

23.2.5. Calculations

24 Pass/fail criteria

24.1. Task 1 – MIL-DTL-6000 hose test

24.1.1. Hose property testing

24.1.2. Hose internal soak testing

24.2. Task 2 – Bladder

24.3. Task 3 – Polysulfide testing

24.4. 140

24.5. Task 4 – Elastomeric testing (o-rings)

24.6. Task 5 – Paint testing

24.7. Task 6 – Fabric testing

24.8. Task 7 – Distribution hose testing

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24.9. Task 8 – Composite resin and fabric

24.9.1. Initial screening test of neat resin and adhesives

24.9.2. Physical property testing of finished composites

24.10. Task 9 – Distribution fuel filters/coalescers

24.10.1. Housings

24.10.2. Filter cartridges

24.10.3. Coalescer cartridges

24.11. Task 10 – Vendor supplied materials

24.12. Task 11 – Wing tank testing

24.13. Task 12 – Grease resistance

24.13.1. Grease solubility

24.13.2. Grease condition

25 Test personnel

26 Test results report

27 References

28 Appendices xiii

Table of appendices

Appendix A – Test Fuel CoA Requirements 144

Appendix B – Flow Path Of Testing Requirements 146

Appendix C – Production of AS5127/1C Flow Sheets 149

Appendix D – Integral Fuel Tank Sealants 151

Appendix E – Additional Materials as O-rings 158

Appendix F – Paint Systems 162

Appendix G – Fabric Systems 167

Appendix H - Large Distribution Hoses 170

Appendix I – Composites Materials 174

Appendix J – Distribution Filters/Coalescers and Tank Coatings 182

Appendix K – Vendor Supplied Materials 187

Table of figures

Figure 1 - Fabric Frame Construction Drawing

Figure 2 - Finished Fabric Frame

Figure 3 - AS5127/1C Figure 22 - Five Inch Peel Specimen Configuration

Figure 4 - AS5127/1C Figure 23 - Four Inch Peel Specimen Configuration

Figure 5 - AS5127/1C Figure 24 - Peel Strength Test

Figure 6 - Example of Panel in a Jar

Figure 7 - Example Fuel Dripping Rig for Paint Staining Test

Figure 8 - Preparing Frame for Fabric Assembly

Figure 9 - Laying Fabric Over Frame with Overlap for Seam

Figure 10 - Example Showing the Glued (bottom) and Unglued (top) Seams

Figure 11 - Example of Finished Fabric System Frame (Poly-Fiber)

Figure 12 - Layout of Tensile Strips

Figure 13 - Tensile Strip with Glued Support

Figure 14 - Wrapping Tensile Strips on Pins for Tensile Testing (ASTM D5035-11, Figure 1) . 79

Figure 15 - Set up of Adhesion Test in Grips xiv

Figure 16 - Example of fitting and cap

Figure 17 - Standard Adhesive Test Panel (ASTM D3163-01, Figure 1)

Figure 18 - Example of Edges Needing Surface Grinding

Figure 19 - Example of a Tabbed Tensile Coupon (ASTM D3039-17, Figure 2)

Figure 20 - Example of a Tabbed V-Notch Coupon (ASTM D5379-19, Figure 8)

Figure 21 - Engineering Drawing of Tensile Coupons (ASTM D3039-17, Figure 2)

Figure 22 - Engineering Drawing of Short Beam Cantilever Coupons (ASTM D2344-22, Figure

2)

Figure 23 - Engineering Drawing of V-Notched Test Coupon (ASTM D5379-19, Figure 2) ... 103

Figure 24 - Example of a Water Displacement Density Measurement

Figure 25 - Example of a Barcol Impressor Hardness Tester

Figure 26 - Short Beam Test Specimen Inserted for Test (ASTM D2344-22, Figure 6)

Figure 27 - Placement of Strain Gages on V-Notch Coupons (ASTM D5379-19, Figure 6)

Figure 28 - V-Notched Beam Test Fixture Schematic (ASTM D5379-19, Figure 3)

Figure 29 - Specimen Placement in the Fixture (ASTM D5379-19, Figure 10)

Figure 30 - Pleated Paper Filter

Figure 31 – Velcon OS 51288 Coalescer/Separator Cartridge xv

Table of tables

Table 1 – Calibration and Validation References

Table 2 – Pass/Fail Criteria of Fuel Tank Sealants

Table 3 – Pass/Fail Criteria of Buna-N Topcoat

Table 4 – Pass/Fail Criteria of Elastomeric O-Rings xvi

Glossary

Definitions, terminology and abbreviations specific to this document and to FAA nomenclature are summarized in the following table.

Term Definition

Calibration Calibration is a set of actions that establishes that the instrument being calibrated is equal to or reports values equal to a standard. The unknown, the instrument being calibrated, will be checked against a known, the standard, at several different points and adjustments made to the unknown to bring it into alignment with the standard.

Composite Within this testing, the following concept is meant by the term “composite”.

Composite structures are formed by combining disparate materials together to form an overall structure with properties different from the individual materials used to construct the final structure. For example, a “fiberglass aircraft” is made of a glass fiber encapsulated in a resin matrix, creating a composition material or composite. Composite does not refer to the chemistry of the resin or fabric.

Exposure Within this document, the term exposure is the placement of specimens in a test fluid at a given temperature for a given amount of time. Exposure also includes the application of test fluid to the surface of the fabric systems using a fuel reservoir and a cotton cloth.

Sample Within this document the following concept is meant by the term “sample”. A sample is the specific material to be prepared as specimens and exposed to test fluids. For example, Manganese-cured polysulfide is a sample, and dichromate-cured polysulfide is a second sample.

Sample set A sample set is all of the individual specimens and all of the test fluids comprising a set of samples to generate a set of data. For example, five nitrile O-rings and five nitrile dimension change specimens in 100LL and five nitrile O-rings and five nitrile dimension change specimens in an experimental test fuel comprise the “Nitrile Sample Set.”

Specimen Within this document the following concept is meant by the term “specimen”.

Specimens are the individual pieces prepared from the sample material, i.e., the five individual test pieces prepared from the MIL-DTL-6000 hose or the single test panel cut from a Meggitt bladder are the test specimens.

Validation As opposed to Calibration, validation is the act of documenting that an instrument will actually and consistently give expected results. This may be done by measuring a specimen with a known value and confirming the instrument reports that value within the repeatability of the instrument. If the expected value does not result, validation has failed, and some additional action must be taken to repair or adjust (calibrate) the instrument.

Executive summary

PAFI-MTP-002 is furnished for the purpose of public use.

A high aromatic ASTM D-910 fuel formulation is required for the screening tests.

This test plan reflects aviation industry best practice for materials test plans with format and content structured accordingly. Processes & procedures reflect industry practices for generating qualification data.

This test plan specifies the requirements for conducting comparative materials compatibility screening tests for a proposed alternative formulation for a fuel sufficient to be an alternative to ASTM D-910.

Successful completion of this test plan provides data supporting FAA Fleet Authorization(s).

The material in this document provides a reference for use in the preparation of test plans for the development of alternative aviation fuels. This document is derived from extensive FAA and industry experience and best practices for evaluating the suitability of aviation fuels for use in the piston powered general aviation fleet. This document is used by the FAA to compare and evaluate new aviation fuels relative to the performance of 100LL aviation gasoline that meets ASTM D910. This document is not intended to provide a method to obtain data to serve as a showing of compliance to regulatory requirements for the certification of aircraft or aircraft engines.

The material in this document does not change or permit deviations from existing regulatory requirements. This material is neither mandatory nor regulatory in nature. Use of this document or any derivative, in an attempt to obtain an FAA authorization of an alternative aviation fuel, should be pre-coordinated and approved by the appropriate FAA office(s) as part of an approved qualification program.

1 Introduction

This test plan specifies the requirements and procedures for conducting comparative compatibility testing of materials, required for participating in the FAA Piston Aviation Fuels Initiative (PAFI) test program.

This data will be used for the evaluation of an unleaded fuel being tested in the PAFI test program. The data will be used as part of the final evaluation of data for fleet authorization(s). Use of this test plan generates data meeting the applicable requirements of [FAA 14 CFR Parts 23 and 33] or ASTM D7826 for material compatibility.

2 Scope

Specific objectives of this plan are stated as follows. Specified materials lists are located in Appendices at the end of this document.

1) Execute compatibility screening of MIL-DTL-6000 Hose, Rubber, Aircraft, Fuel, Oil, Coolant, Water, And Alcohol, and MIL-DTL-5593 Hose, Aircraft, Low Pressure Air and

Vacuum, Flexible, related to determining swell characteristics, and changes tensile/elongation properties following fuel exposure.

2) Execute compatibility screening of specified fuel bladder construction related to degradation and delamination of the internal lining following fuel exposure in compliance with applicable parts of FAA TSO-C80 and ASTM D7826.

3) Execute compatibility screening of specified integral fuel tank sealants related to changes to tensile/elongation, volume swell and peel strength properties following fuel exposure.

Specified materials are provided in Appendix D.

a. The list of integral fuel tank sealants includes a low strength access panel sealant and a liquid Buna-N topcoat which have material specific variations to the described required testing. Differences are provided.

4) Execute compatibility screening of specified nitrile, fluorosilicone, and fluorocarbon elastomers in the form of O-rings, related to changes in hardness, tensile/elongation, volume change and compression set following fuel exposure. These materials are in addition to the full materials list specified in ASTM D7826. Specified materials are provided in Appendix

E.

5) Execute comparison testing of paint staining and adhesion impacts of a specified matrix of paint systems following fuel exposure. Specified materials are provided in Appendix F.

6) Execute comparison testing of fabric tensile/elongation of specified fabric systems following fuel exposure. Specified materials are provided in Appendix G.

7) Execute comparison testing of physical properties and long-term fill impacts of specified manufacturers of large distribution hoses. Specified materials are provided in Appendix H.

8) Execute comparison testing of specified resins, adhesives, foam cores, and fabrics used for composite structure construction. Specified materials are provided in Appendix I.

9) Execute comparison testing of filter elements, coalescer elements, and housings, and fuel tank coatings used in distribution systems. Specified materials are provided in Appendix J.

10) Execute comparison testing of vendor supplied materials used by original equipment manufacturers. Specified materials are provided in Appendix K.

11) Execute grease resistance to fuel exposure testing. Specified materials are provided in

Appendix L.

The following test plan includes the requirements for confirming baseline properties, test set-up, instrumentation, and supporting documentation such as material and fuel certification documents as prerequisites to the testing identified. This test plan is used in conjunction with ASTM D7826 to prepare data packages for review of a fuel for fleet authorization(s).

Comparative testing of materials for screening purposes is executed at specified temperatures and durations which may be modifications from existing industry standards. The modifications have been selected by industry representatives as providing the desired screening data sufficient for consideration of a proposed unleaded fuel for acceptance into the FAA PAFI fuel testing program.

This PAFI Materials Test Plan consists of tasks executed in addition to ASTM D7826 materials compatibility testing to document physical changes in materials as compared to those changes experienced by a D910 compliant 100LL aviation gasoline produced with a high aromatic content.

Although Specification D910 does not include an explicit maximum aromatic limit, other specification limits effectively restrict the aromatic content of aviation gasolines. For this testing, the high aromatic

ASTM D910 compliant test fuel shall be fuel produced with 15% (-0%/+3%) toluene by volume per

ASTM D3606. All other Table 1 properties shall be D910 compliant. In addition, the unleaded fuel shall be a “worst case” fuel for material compatibility testing. Worst case is defined as a fuel blended with the maximum amounts of reactive components permitted by the offered fuel’s standard. Reactive components include, but are not limited to, aromatics, alcohols, ethers, amines, and other chemicals not traditionally used in aviation gasoline. Maximum amounts are defined by the maximum amounts permitted in the fuel by the respective fuel standard, be that an industry standard, company standard, or other controlling document . While this blend should be compliant to the target standard, it is recognized that the blending of the fuel to have this maximum content may not produce an “optimum fuel” for performance and operation. Data from both the unleaded test fuel and the high aromatic content 100LL aviation gasoline exposure will be further compared to the existing pass/fail criteria developed for material certification. In cases where the 100LL does not meet the pass/fail criteria provided, the resulting 100LL data will be used as a measure of minimum performance.

Requirements for confirming test equipment configuration, test instrumentation, and supporting documentation such as fuel certification are pre-requisites to the testing identified.

It is known under certain conditions, exposure to light can cause precipitation of the tetraethyl lead and fading of the dye in 100LL fuels. In order to avoid confounding of the test data, all fuel shall be stored in a manner which will minimize exposure to light, particularly sunlight. This includes bulk samples, such as 5-gallon specimens, laboratory specimens, and specimens during testing. Where possible, the fuel shall be stored in metal cans, brown borosilicate laboratory bottles, or containers wrapped in foil.

Alternatively, fuel may be stored in clear laboratory glassware with the expectation it will be stored in low/no light locations such as a flammables cabinet or during oven testing.

2.1. Provisos

The following identifies significant assumptions, requirements, and provisions associated with the testing prescribed within this test plan. Testing performed pursuant to this test plan provides data supporting FAA fleet authorization(s) for PAFI unleaded fuels. Testing performed to this test plan must be witnessed by an identified designated representative of the FAA. This may be achieved through the use of a Designated Engineering Representative (DER), or another representative approved by the AIR-

650 or PAFI Advisory Committee prior to executing testing.

All the results of the testing performed, and the associated data collected under the following test plan are considered competition sensitive and proprietary by the fuel offeror and are subject to NDA between the FAA and the Fuel Offeror.

3 Objectives

The objectives of this document are in addition to the materials compatibility testing of ASTM D7826.

The specified materials for testing covered by this document are referenced in separate appendices at the end of this document. The objectives of the PAFI Materials Test Plan comparative materials compatibility tests are defined as follows.

1) Demonstrate changes in tensile/elongation and changes in volume swell within specified limits or no greater than that experienced with 100LL when MIL-DTL-6000 nitrile hose is exposed to fuel at 21-27 °C )70 – 80 °F) for 48 and 24 hours respectively.

2) Demonstrate swelling within specified limits or no greater than that experienced with 100LL when MIL-DTL-6000 nitrile hose and MIL-DTL-5593 are exposed serially to fuel at room temperature and fresh fuel at 71 °C (160 °F) for 30 days at each temperature.

3) Demonstrate no cracking, blistering, delamination or other visual surface degradation of the internal surface of fuel bladder sheets following exposure to the fuel at 60 °C (140 °F) for 42 days (~1000 hours).

4) Demonstrate non-volatile gum residues from fuel exposed to a standard fuel bladder panel within specified limits when tested in compliance with the modified TSO-C80 simulated stand test.

5) Demonstrate swelling, changes in tensile/elongation, and changes in hardness of specified internal tank sealants prepared in compliance to SAE AS5127, Section 7.7 is within specified limits or no greater than 100LL when exposed to fuel at 60 +3/ -0 °C (140 +5/ -0 °F) for 42 days (~1000 hours). Testing will include fresh fuel exchange at day 14 and 28. The tensile/elongation and hardness changes shall be stabilized to within 10% of the day 14 value to assure an endpoint in fuel property changes. See Appendix D for materials.

6) Demonstrate changes in peel strength of specified internal tank sealants prepared in compliance with ASE AS5127, Section 8.0 are within specified limits or no greater than that experienced with 100LL when exposed to fuel at 60 +2/-0 °C (140 +5/-0 °F) after 42 days with fresh fuel changes at day 14, and 28. See Appendix D for materials.

7) Demonstrate changes in peel strength of specified internal tank sealants prepared in compliance with ASE AS5127, Section 8.0 are within specified limits or no greater than that experienced with 100LL when exposed to 100LL at 60 +2/-0 °C (140 +5/-0 °F) for 70 days followed by exposure to either 100LL (baseline) or test fuel for 70 days at 60 +2/-0 °C (140

+5/-0 °F)

8) Demonstrate changes in peel strength of PR-1005-L Buna-N slosh coating prepared in compliance with AMS-S-4383, 4.6.8 are within specified limits or no greater than that experience with 100LL when exposed for 48 hours at 25 ° ± 1 °C (77 ° ± 2) following 72 hours of air cure and 24 hours at 49 °C (120 °F).

9) Demonstrate changes in extracted gum residues from Buna-N topcoat sealant is less than 20 mg/ 100 mL or no greater than that experienced with 100LL when exposed to fuel at room temperature for 48 hours.

10) Demonstrate swelling, and changes to tensile/elongation, hardness, and compression set within specified limits or no greater than that experienced with 100LL when specified nitrile, fluorosilicone and fluorocarbon (Viton™) O-rings are exposed to fuel at 71 ±3 °C (160 ±5

°F) for 42 days. Testing will include fresh fuel exchange at day 14 and 28. The tensile/elongation and hardness changes shall be stabilized to within 10% of the day 14 value to assure an endpoint in fuel property changes. See Appendix E for materials.

11) Demonstrate that a matrix of paint systems does not experience staining, change in hardness, or loss of adhesion greater than that experienced with 100LL when exposed to fuel at room temperature for 28 days with a fuel change and visual inspection at day 14. See Appendix F for materials.

12) Demonstrate that a matrix of paint systems does not experience staining or removal when exposed to fuel at room temperature as a drip to the surface under controlled conditions of rate and volume. See Appendix F for materials.

13) Demonstrate that a matrix of specified fabric systems does not experience a loss of tensile/elongation, adhesion, or cross-linking (blistering, bubbling, removal, etc.) greater than that experienced with 100LL when exposed to fuel at room temperature for 48 hours. Visual inspection and maintenance of a fuel reservoir will be done after 30 minutes, 1 hour, 4 hours, 8 hours, 24 hours, and 48 hours. Frequency of maintaining the fuel reservoir will be dictated by the volatility of the test fuel. See Appendix G for materials.

14) Demonstrate that changes in hardness, volume, and density of specified large distribution hoses is no greater than that experienced with 100LL when exposed to fuel at 71 °C (160 °F) for 28 days. See Appendix H for materials.

15) Demonstrate that changes in permeation, performance, and hydrostatic proof pressure of specified large distribution hoses are no greater than that experienced with 100LL when exposed to fuel at ambient conditions for 16 weeks. See Appendix H for materials.

16) Demonstrate that changes in weight gain, tensile/elongation, and break strength of specified composite matrices are no greater than those experienced with 100LL when exposed to fuel at ambient conditions for 28 days. See Appendix I for materials.

17) Demonstrate that changes in housing condition are no greater than those experienced with

100LL when exposed to fuel at ambient conditions for 500 hours. See Appendix J for materials.

18) Demonstrate that changes in filter cartridge dimensions and condition are no greater than those experienced with 100LL when exposed to fuel at ambient conditions for 500 hours. See

Appendix J for materials.

19) Demonstrate that changes in filter coalescer condition are no greater than those experienced with 100LL when exposed to fuel at ambient conditions for 500 hours. See Appendix J for materials.

20) Demonstrate that changes in fuel water reaction, surface tension, and material migration are no greater than those experienced with 100LL when exposed to fuel at ambient conditions for

500 hours. See Appendix J for materials.

21) Demonstrate that changes in vendor supplied materials are no greater than those observed in

100LL baseline fuel. See Appendix K for materials.

22) Individual airframe manufacturers may select aircraft for further testing of fuel tank performance. This includes but is not limited to identifying aircraft with “wet wings” and performing testing as determined by the manufacturer. This testing will be for evaluating compatibility and functionality of the sealants following exposure to test fuels. Testing will be done at the manufacturers, or at their designated location with aircraft owned by or designated by the manufacturer.

23) Demonstrate that changes to the resistance of AMS-G-6032 to fuel is no greater than experienced with 100LL when exposed at ambient conditions for 8 hours, or after drying for

24 hours.

4 PAFI materials test plan

This test plan provides materials and test procedures which are in addition to those presented in ASTM

D7826. ASTM D7826 is a guidance document which includes material compatibility testing on metallic and non-metallic materials and the testing to be performed. All of the materials compatibility testing in ASTM D7826 are to be completed. The following test plan includes materials or procedures which are not currently included in ASTM D7826, or which are deviations from ASTM D7826. In cases where materials or tests are in both ASTM D7826 and this document, this document shall take precedence.

NOTE: ASTM D7826 includes HYSOL EA9628 structural metal bonding adhesive in the materials list. It does not, however, clearly indicate that the use of Solvay BR-127 epoxy primer is required for test panel construction. Furthermore, due to the difficulty in procuring the EA9628 adhesive, it is recommended the offeror work with the FAA and Piper to procure finished panels for the testing. This update is intended to be added to ASTM D7826 in a future revision, but at this time is not explained in D7826.

NOTE: ASTM D7826 does not currently include acetal resin (Delrin) or Tygon® F-4040-A tubing in the materials list. Testing of Delrin and Tygon® F-4040-A shall be added to the materials list of

ASTMD7826. All non-metallic test protocols found in D7826 shall be performed on acetal resin and

Tygon® tubing, and tested for changes in hardness, density, and volume. Materials shall be tested at room temperature and 71°C (Delrin) or 60 °C (Tygon). These materials are intended to be added to

ASTM D7826 in a future revision.

The individual tasks encompassed in the PAFI Materials Test Plan are presented in the following sections of this document. Each test follows a common format with general procedures, processes, and test instrumentation common to each test. See referenced Appendices for specific materials lists.

1) MIL-DTL-6000/MIL-DTL-5593 Hose Test

2) Bladder (Fuel Cell) simulated stand test on sheets

3) Integral tank sealant (Polysulfide) Screening Tests

4) Additional Elastomeric Material (O-ring) Testing

5) Paint Staining and Adhesion Testing

6) Fabric Strength and Cross-Linking Testing

7) Large Distribution Fuel Hose Physical Properties and Performance Testing

8) Composite Resin and Fabric Screening Testing

9) Distribution System Filtration/ Coalescence Element Compatibility and Fuel Tank Coating

Testing

10) Vendor Supplied Materials

The test plans may be executed by a third-party organization contracted by the fuel formulator in order to generate and collect the specified data. Integral fuel tank sealants test protocols are designed to be executed with participation of the product OEM’s or other AS 9100 approved test facilities. All testing must be witnessed by a designated representative of the FAA. This data is considered acceptable for inclusion into the final FAA assessment for fleet authorization.

To be considered for fleet authorization, the test plans prepared to support the FAA PAFI Materials

Test Plan for unleaded fuels are subjected to the following review and approval protocol.

1) The FAA test plans follow a format and content consistent with established practices.

2) Draft test plans are furnished to the FAA AIR600 office for review and approval. These test plans shall include, at a minimum, the location of testing, the specific materials and equipment to be used, and the plans for test witnessing by an FAA designated representative.

3) Upon concurrence from AIR600 Alternative Fuel Program Staff (AFPS),

4) A final test plan will be released incorporating changes resulting from AIR600 review.

5) All changes and referrals to this test plan should reference the latest revision level and date.

5 Applicable MIL, FAA, SAE & ASTM requirements

The following is a listing of the applicable FAA, SAE, and ASTM documents which contain information relevant to the testing specified by this test plan. The latest revision number should be used unless otherwise indicated. The revision number used for testing shall be recorded.

5.1. Military handbooks & standards

Military reference material and standards applicable to the testing identified are listed as follows.

1) MIL-HDBK-510-1D “Department of Defense Handbook, Aerospace Fuels Certification”

2) MIL-DTL-5593 “Hose, Aircraft, Low Pressure Air and Vacuum, Flexible”

3) MIL-DTL-6000 “Hose, Rubber, Aircraft, Fuel, Oil, Coolant, Water, And Alcohol”

4) MIL-PRF-6855 “Rubber, Synthetic, Sheets, Strips, Molded or Extruded Shapes, General

Specification For”

5) MIL-DTL-25988 “Rubber, Fluorosilicone Elastomer, Oil– And Fuel–Resistant, Sheets, Strips, Molded Parts, And Extruded Shapes” (Supersedes SAE-AMS-R-25988)

6) CCC-C-432 “Cloth, Sheeting, Cotton, (Unbleached, Bleached, and Dyed) (Supersedes Fed.

Spec. CCC-C-432) Inactivated 11 April 2002

5.2. FAA advisory circulars & orders

1) FAA Advisory Circular 33.19-1,” Guidance Material for 14 CFR §33.19 Durability for

Reciprocating Engine Redesigned Parts”

2) FAA Advisory Circular AC33.4-1,” Instructions for Continued Airworthiness”

3) FAA Order 8110.4C, “Type Certification Process”

FAA guidance and reference material applicable to Part 33 reciprocating engines are listed as follows.

1) FAA Advisory Circular 33.19-1,” Guidance Material for 14 CFR §33.19 Durability for

Reciprocating Engine Redesigned Parts”

2) FAA Advisory Circular AC33.4-1,” Instructions for Continued Airworthiness”

3) FAA Order 8110.4C, “Type Certification Process”

4) FAA Technical Order C80, “Subject: TSO-C80, Flexible and Oil Cell Material”

5.3. Federal test methods

1) Federal Test Method Standard No. 601, April 12, 1955, “Rubber: Sampling and Testing”, Method 4111, “Tensile Strength.”

2) Federal Standard 791, November 6, 2007, “Testing Method of Lubricants, Liquid Fuels, and

Related Products”, Method 5414.4, “Resistance of Grease to Fuel.”

5.4. SAE standards

SAE standards applicable to the testing identified are listed as follows.

1) SAE AS5127 “Aerospace Standard Test Methods for Aerospace Sealants Two-Component

Synthetic Rubber Compounds”

2) SAE AMS3276 “Sealing Compound, Integral Fuel Tanks and General Purpose, Intermittent

Use to 360 °F (182 °C)”

3) SAE AMS3277 “Sealing Compound, Polythioether Rubber Fast Curing for Integral Fuel Tanks

& General Purpose, Intermittent Use to 360°F (182°C)”

4) SAE AMS3281 “Sealing Compound, Polysulfide (T) Synthetic Rubber for Integral Fuel Tank and Fuel Cell Cavities Low Density for Intermittent Use to 360 °F (182 °C)”

5) SAE AMS3284 “Sealing Compound, Low Adhesion, for Removable Panels and Fuel Tank

Inspection Plates”

6) SAE AMS-S-4383 “Sealing Compound, Topcoat, Fuel Tank, Buna-N Type”

7) SAE AMS-P-5315 “Acrylonitrile-butadiene (NBR) Rubber For Fuel-Resistant Seals 60 to 70”

8) SAE AMS-7276 “Rubber: Fluorocarbon (FKM) High-Temperature-Fluid Resistant Low

Compression Set For Seals In Fuel Systems and Specific Engine Oil Systems”

9) SAE AMS7379 “Rubber: Fluorocarbon Elastomer (FKM) Low Temperature Sealing Tg -40 °F

(-40 °C) 70 to 80 Type ‘A’ Hardness For Elastomeric Seals in Aircraft Engine Oil, Fuel and

Hydraulics Systems”

10) SAE AMS7287 “Fluorocarbon Elastomer (FKM) High Temperature / HTS Oil Resistant / Fuel

Resistant Low Compression Set / 70 to 80 Hardness, Low Temperature Tg -22 °F (-30 °C) For

Seals in Oil / Fuel / Specific Hydraulic Systems” – Replaces SAE AMS-R-83485, Type 1

11) SAE AMS-S-8802 “Sealing Compound, Fuel Resistant, Integral Fuel Tanks and Fuel Cell

Cavities”

12) SAE-AMS-R-25988, “Rubber, Fluorosilicone Elastomer, Oil-and-Fuel-Resistant, Sheets, Strips, Molded Parts, and Extruded Shapes” – Cancelled, Superseded by MIL-DTL-25988

13) SAE-AMS-R-83485 “Rubber, Fluorocarbon Elastomer, Improved Performance at Low

Temperatures”–Cancelled, Type 1 replaced by AMS7287

14) AMS-QQ-A-250/5B “Aluminum Alloy Alclad 2024, Plate and Sheet”

15) SAE J905 SEP2009 Fuel Filter Test Methods

5.5. ASTM guidance & practices

ASTM guidance and standards applicable to the testing identified are listed as follows. Data provided by this test plan will support development of an ASTM production specification for each of the unleaded fuels. Within this document, references to content may be revision specific, for example section references, however use of the most current version of the standards are permissible. STM is

“Standard Test Method”

1) ASTM D380 “STMs for Rubber Hose”

2) ASTM D381 “STM for Gum Content in Fuels by Jet Evaporation”

3) ASTM D395 “STMs for Rubber Property—Compression Set”

4) ASTM D412 “STMs for Vulcanized Rubber and Thermoplastic Elastomers—Tension”

5) ASTM D413 “STMs for Rubber Property – Adhesion to Flexible Substrate”

6) ASTM D471 “STM for Rubber Property—Effect of Liquids”

7) ASTM D1094 “STM for Water Reaction of Test Fuels”

8) ASTM D1331 “STM for Surface and Interfacial Tension of Solutions of Paints, Solvents, Solutions of Surface-Active Agents, and Related Materials”

9) ASTM D1414 “STMs for Rubber O-Rings”

10) ASTM D2240 “STM for Rubber Property—Durometer Hardness”

11) ASTM D2276 “STM for Particulate Contaminant in Aviation Fuel by Line Sampling”

12) ASTM D2344 “STM for Short-Beam Strength of Polymer Matrix Composite Materials and

Their Laminates”

13) ASTM D2583 “STM for Indentation Hardness of Rigid Plastics by Means of a Barcol

Impressor”

14) ASTM D3039 “STM for Tensile Properties of Polymer Matrix Composite Materials

15) ASTM D3163 “STM for Determining Strength of Adhesively Bonded Rigid Plastic Lap-Shear

Joints in Shear by Tension Loading”

16) ASTM D3359 “STM for Measuring Adhesion by Tape Test”

17) ASTM D3363 “STM for Film Hardness by Pencil Test”

18) ASTM D3505 “STM for Density or Relative Density of Pure Liquid Chemicals”

19) ASTM D5035 “STM for Breaking Force and Elongation of Textile Fabrics (Strip Method)”

20) ASTM D5379 “STM for Shear Properties of Composite Materials by the V-Notched Beam

Method”

21) ASTM D7826 “Standard Guide for Evaluation of New Aviation Gasolines and New Aviation

Gasoline Additives”

6 Description of test articles

This test plan covers the screening materials compatibility of multiple test articles. Multiple test articles may be required within each individual task. Details in this section are in addition to or in lieu of materials described in ASTM D7826.

6.1. MIL-DTL-6000 hose – aircraft hose

In order to complete the hose testing, two sizes of MIL-DTL-6000 compliant hoses are required.

1) 3/8” or -6 hose in 12-to-15-inch sections; a total of a minimum of 10 continuous feet. In order to perform the necessary fuel gum testing, four 12-to-15-inch specimens per tested fuel are required. A total of eight specimens is required per fuel set (four for experimental fuel and four for 100LL aviation gasoline). This hose is used to prepare the diameter swell testing.

2) 2” ( -32) hose minimum up to 2 ½” (-40); a total of 9 feet. This size hose is used for tensile/elongation and volume change testing and will be used to prepare ASTM D412, Die C tensile strips and 1”x2” volume change specimens. The hose must be a minimum diameter of

2” to provide sufficient length for Die C tensile strips. Due to manufacturing schedules, availability of large diameter hose may require the purchase of larger diameter MIL-DTL-6000 hose up to 2 ½”. This is permissible as long as the hose is not reinforced, i.e., with metal braid.

3) Hose ends and AN fittings used to cap and seal the hose specimens. These fittings shall be installed into the -6 hose using industry standard assembly processes.

6.2. MIL-DTL-5593 hose – aircraft hose

In order to complete the hose testing, length(s) of hose must be procured from Piper (P/N 187-058 Bulk

Hose). The military specification is insufficient in specifying the material and construction of the hose specific to use by Piper.

1) 3/8” or -6 hose in 12-to-15-inch sections; a total of a minimum of 10 continuous feet. In order to perform the necessary fuel gum testing, four 12 to 15” specimens per tested fuel are required.

A minimum of eight specimens is required per fuel set (four for the experimental fuel and four for the 100LL aviation gasoline). This hose is used to prepare the diameter swell testing.

2) Hose ends and AN fittings used to cap and seal the hose specimens. These fittings shall be installed into the -6 hose using industry standard assembly processes.

6.3. Fuel bladders AKA fuel cells

In order to complete the Simulated Stand testing, samples from multiple manufacturers are required.

The samples are prepared from fully constructed bladder including an airworthy patch and a seam in the form of panels. The sheets may be cut from finished, purchased fuel cells.

The fully constructed panel for the simulated stand test can be achieved by cutting the panels from fuel cells manufactured under either FAA-PMA or an original equipment product and supplied with an

FAA Form 8130-3. The specimens shall be cut from the fuel bladder in a manner to include a flat area across which there is a seam. The airworthy patch may be prepared prior to cutting the specimens or after the specimens have been prepared. Patching shall be in accordance with applicable ICA’s

(Instructions for Continued Airworthiness).

Specimens to be used for the simulated stand test will be cut from an open area to produce a set of panels of sufficient size to fit the chosen exposure test rig (See Section 10.9). Panel shall be flat without corners or mounting hardware.

Fuel cell part numbers which have been identified as acceptable include:

1) 2F1-6-32514-17

2) 2F1-6-37819-18

6.4. Polysulfide sealants and Buna-N topcoat testing

The integral tank sealants must be prepared as cured flow sheets as described in AS5127, Section 7.7

Tensile Strength and Elongation, see Appendix D for sealant descriptions. The sealants, except for

AMS 3284 Low Adhesion Sealing Compound, and AMS-S-4383 Buna-N Topcoat must also be prepared for peel testing as described in AS5127, Section 8. Additionally, AMS 3281 sealant is also to be tested applied to BT250/eglass fiber reinforced composite panels.

One way tank sealants are procured is in a Semkit® package which is a complete, multi-component plastic cartridge assembly which stores, mixes, and applies multiple component sealants. Sufficient

Semkits® must be procured to produce flow sheets sufficient to prepare the ASTM D412 Die C tensile strips and the ASTM D471 dimension change specimens, and to prepare the peel strength specimens.

The number of Semkits® required is determined by the size of the flow sheets, the number of specimens required, and the number of peel strength specimens.

Sealants shall be specified as being produced from the same lot of sealants. If multiple lots of material must be used, all specimens within a type, for example the flow sheets, shall be from the same lot. The goal is to assure that the specimens exposed to the baseline 100LL fuel are from the same lot as those exposed to the test fuel.

This test protocol requires the procurement of integral tank sealants and one type of Buna-N topcoat

(Slosh Coat). Example source and part numbers are provided in Appendix D. For exact source/part numbers see PAFI Materials Test Matrix. Each material tested must be from the same lot and

Certificates of Conformance should be included in the test report. In addition to the full material compatibility testing on the materials listed in Appendix D, Table 1, validation testing must be performed on specified sealants by the listed manufacturers and part numbers in Appendix D, Table 2.

6.5. Additional materials; nitrile, fluorosilicone, and

fluorocarbon O-rings

In order to provide initial screening information related to elastomeric compatibility, materials in the form of O-rings are to be tested. This testing is in addition to the materials compatibility provided in

ASTM D7826 and is useful for pre-screening. This testing also provides data related to actual form and function.

In order to facilitate the tests, each O-ring may be procured in two sizes. For example, each O-ring may be procured as a -210 (1” OD) for use in compression set testing and as a -226 (2 ¼” OD) for use in tensile/elongation and hardness testing. O-rings in these two sizes provide for acceptable repeatability from the specified test methods. Certificates of Quality, Certificates of Conformance or other documentations containing Lot information are to be requested and provided in final report. Materials specified are provided in Appendix E.

6.6. Paint test

In order to provide information on the propensity of a fuel to cause staining or loss of adhesion, a matrix of paint systems prepared to airworthy standards are required. For proper application and adhesion, paints are described as systems, which may include any or all of the following: a surface treatment, a primer, a base coat, and a clear coat. In a system, the different materials are not automatically interchangeable. Using unmatched components often invalidates the manufacturer’s warrantees or guarantees. To assure proper application of the systems, a professional facility capable of applying paint is recommended.

The paint systems as specified by the test plan are shown in Appendix F. Note that for the paint systems provided, the paint manufacturer listed is part of the requirements of the Material Test Plan. Each paint system is to be applied to 0.040” 2024-T3 aluminum per AMS-QQ-A-250/5B. The aluminum shall be sheared into 5.08 cm x 10.16 cm (2” x 4” squares) prior to painting to avoid edge effects and damage to the paint by the shearing process.

In addition to the aircraft paint systems, compatibility of the coatings used on distribution fuel tanks must be considered. The coating systems are applied and tested in the same manner as aircraft paint systems. The distribution coating systems are provided in Appendix J.

6.7. Fabric test

In order to provide information on the propensity of a fuel to cause loss of crosslinking, a loss of adhesion, or a loss of tensile strength, a matrix of fabric systems prepared to airworthy standards is required. For proper application and adhesion, fabrics are described as systems, which may include any or all of the following: the fabric, a surface treatment, a cement, and a coating. In a system, the different materials are not automatically interchangeable. Using unmatched components often invalidates the manufacturer’s warrantees or guarantees. To assure testing of the fabric system specifically, the test articles do not include a final paint layer. This provides testing of the fabric system itself and is indicative of unpainted regions, such as interior surfaces.

The fabric systems as specified by the test plan are shown in Appendix G. Note that for the fabric systems provided, the manufacturer listed is part of the requirements of the Material Test Plan. Each fabric system is to be prepared by construction on an industry standard wooden test frame described below and shall include a seam both attached and unattached to a support structure. The system shall be prepared to airworthy standards. None of the systems include any form of final paint which would confound the collection of structural data.

6.8. Distribution hoses

In order to provide initial screening information related to elastomeric compatibility of airport distribution hose, materials in the form of large diameter distribution hose are required. Hose testing is designed to provide information on the propensity of a fuel to cause changes in physical response of the material to the fuel which is significantly different that that experienced when exposed to conventional ASTM D910 100LL aviation gasoline.

The hoses are procured as a 1 ½” minimum diameter hose. Either a regular or a defueling/Jac Riser hose may be used. The primary difference is the use of steel wire helix on the defueling hose; thus, a regular hose is preferred for the preparation of…