Results of Intermediate-Scale Flammability Tests Performed

DOT/FAA/AR-06/4 Office of Aviation Research and Development Washington, DC 20591

Results of Intermediate-Scale Flammability Tests Performed on HypalonTM RB71 Aircraft Duct Insulation Patricia Cahill Timothy Marker John Reinhardt February 2006 Data Report This document is available to the U.S. public through the National Technical Information Service (NTIS), Springfield, Virginia 22161.

U.S. Department of Transportation Federal Aviation Administration

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein solely because they are considered essential to the objective of this report. This document does not constitute FAA certification policy. Consult your local FAA aircraft certification office as to its use. This report is available at the Federal Aviation Administration William J. Hughes Technical Center's Full-Text Technical Reports page: actlibrary.tc.faa.gov in Adobe Acrobat portable document format (PDF).

Technical Report Documentation Page 1. Report No. DOT/FAA/AR-06/4

2. Government Accession No. 3. Recipient's Catalog No.

5. Report Date

February 2006

4. Title and Subtitle

RESULTS OF INTERMEDIATE-SCALE FLAMMABILITY TESTS PERFORMED ON HYPALON™ RB71 AIRCRAFT DUCT INSULATION 6. Performing Organization Code

ATO-P R&D

7. Author(s)

Patricia Cahill, Tim Marker, and John Reinhardt 8. Performing Organization Report No.

10. Work Unit No. (TRAIS)

9. Performing Organization Name and Address

Federal Aviation Administration William J. Hughes Technical Center Airport and Aircraft Safety R&D Division Fire Safety Branch Atlantic City International Airport, NJ 08405

11. Contract or Grant No.

13. Type of Report and Period Covered

Data Report 12. Sponsoring Agency Name and Address

U.S. Department of Transportation Federal Aviation Administration Office of Aviation Research and Development Washington, DC 20591

14. Sponsoring Agency Code ANM-100

15. Supplementary Notes

16. Abstract

Intermediate-scale flammability testing of Hypalon™ RB71, a thermal acoustical insulation primarily used to insulate ducts, was conducted in a section of a wide-body aircraft. The aircraft section was configured to represent the attic area of a transport category aircraft. Baseline tests were also conducted using metallized Tedlar™ film cover over fiberglass to wrap the ducts. Temperature versus time and the relative energy release rate versus time were evaluated and are presented in this report. 17. Key Words

Intermediate-scale flammability test, Hypalon™ RB71, Thermal acoustical insulation

18. Distribution Statement

This document is available to the public through the National Technical Information Service (NTIS) Springfield, Virginia 22161.

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of Pages

26 22. Price

Form DOT F1700.7 (8-72) Reproduction of completed page authorize

TABLE OF CONTENTS

Page INTRODUCTION 1

Purpose 1 Background 1

TEST SETUP, MATERIALS, AND RESULTS 1

Baseline Tests 3 Hypalon RB71 Tests 7 Additional Baseline Tests of Metallized Tedlar for Configuration Consistency 14

iii

LIST OF FIGURES

Figure Page 1 Fuselage Section With Ducts Installed 2 2 Thermocouple Locations 2 3 Test 1 3 4 Test 1—Temperature vs Time 4 5 Test 1—Relative Energy Release Rate vs Time 4 6 Test 2 5 7 Test 2 in Progress 5 8 Test 2—Temperature vs Time 6 9 Test 2—Relative Energy Release Rate vs Time 6 10 Test 3 7 11 Test 3 in Progress 8 12 Test 3—Temperature vs Time 8 13 Test 3—Relative Energy Release Rate vs Time 9 14 Test 3—Posttest Photograph of Ducts 9 15 Test 4—Near Completion 10 16 Test 4—Temperature vs Time 10 17 Test 4—Relative Energy Release Rate vs Time 11 18 Test 4—Posttest Photograph of Ducts 11 19 Test 5 12 20 Test 5—Temperature vs Time 12 21 Test 5—Relative Energy Release Rate vs Time 13 22 Test 5—Posttest Photograph of Ducts 13 23 Test 6 15 24 Test 6—Temperature vs Time 15 25 Test 6—Relative Energy Release Rate vs Time 16 26 MPV Test 6—Posttest Photograph of Ducts 16 27 Test 7 17 28 Test 7—Temperature vs Time 17 29 Test 7—Relative Energy Release Rate vs Time 18 30 Test 8—In Progress 18 31 Test 8—Temperature vs Time 19 32 Test 8—Relative Energy Release Rate vs Time 19 33 Test 8—Posttest Photograph of Ducts 20

iv

LIST OF TABLES

Table Page 1 Distance From Top of Insulated Ducts to Aluminum Surface of Test Article 14

v/vi

INTRODUCTION

PURPOSE.

This report presents data collected from intermediate-scale flammability tests performed on aircraft thermal acoustic insulation. BACKGROUND.

Thermal acoustic insulation is used in numerous locations throughout an aircraft. One particular insulation, Hypalon™ RB71 film laminated to polyimide foam, is used extensively to insulate ducts. Hypalon is a trademark of DuPont de Nemours. It is a chloro-sulfonated polyethylene elastomer and is bonded to the polyimide foam with adhesive. This particular Hypalon RB71 assembly has been used in transport category aircraft for a number of years. In November 2005, intermediate-scale flammability tests were run by the Fire Safety Branch, Airport and Aircraft Safety R&D Division at the Federal Aviation Administration William J. Hughes Technical Center. This testing evaluated the Hypalon RB71 assembly under a realistic fire scenario. Baseline tests were also conducted with metallized Tedlar™ film cover/fiberglass blankets encapsulating the ducts. The variation of temperature versus time and relative energy release rate versus time were evaluated during these tests.

TEST SETUP, MATERIALS, AND RESULTS

The fuselage section with three, 12-inch-diameter, 10-foot-long ducts (stove pipe ducts) used for this testing is shown in figure 1. Thermocouples were placed in various locations in the test article to monitor temperatures during testing and are shown in figure 2. A polyurethane foam block measuring 4 by 4 by 9 inches with 10 cubic centimeters of Heptane served as the ignition source.

1

FIGURE 1. FUSELAGE SECTION WITH DUCTS INSTALLED

9 10

1 2

7

3

4

5

6

8

TC 4” below ceiling4” out from aft last rib face

TC 3/4” below ceiling1” out from last aft rib face

TC 1” Below CeilingAbove Ignition Block

TC on Duct(same for 3, 4, 5, 6 & 8)

½ L

2’ (Typical)

DuctsFuselage Crown

TC 4” below ceiling4” out from last fwd rib faceTC 3/4” below ceiling

1” out from last fwd rib faceFwd

Aft

Aft Last Rib6.25”

Fwd Last Rib

5.875”

FIGURE 2. THERMOCOUPLE LOCATIONS

2

BASELINE TESTS.

Two baseline tests were conducted. In each test, the fuselage section and ducts were insulated as described below. Six bay blankets were installed in the test article, with cap strips covering the fuselage formers. The bay blankets were fabricated with three layers of 0.42 pound per cubic foot (pcf) density fiberglass and covered with metallized Tedlar film, which weighed 1 ounce per square yard (oz/yd2). The cap strips were fabricated with one layer of 0.42 pcf-density fiberglass and covered with the same metallized film as the bay blankets. The three ducts were wrapped with three layers of 0.42-pcf-density fiberglass and covered with metallized Tedlar film weighing 1 oz/yd2. The duct cover assembly was held together with 4-inch-wide metallized Tedlar tape on the top of each duct. Eight-inch concrete block spacers were used to increase the volume of test area in the first test. They were placed at the corners of the fuselage section. The concrete block spacers can be seen in the rear of figure 1. The first test (test 1), with the foam block almost fully consumed, is shown in figure 3. The temperature versus time graph is shown in figure 4, and the relative energy release rate versus time is shown in figure 5. In the second baseline test (test 2), the spacers were removed, as shown in figure 6. The foam block was placed at the opposite end of the test article. The test in progress is shown in figure 7. The temperature versus time graph is shown in figure 8, and the relative energy release rate versus time is shown in figure 9. The distance from the top of the insulated ducts to the aluminum surface of the test article for tests 1 and 2 is given in table 1.

FIGURE 3. TEST 1

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Time (min)

Tem

pera

ture

(deg

F)

Crown Temp 1 (degF)Crown Temp 2 (degF)Duct Temp 3 (degF)Duct Temp 4 (degF)Duct Temp 5 (degF)Duct Temp 6 (degF)Ignition Temp 7 (degF)Duct Temp 8 (degF)Crown Temp 9 (degF)Crown Temp 10 (degF)

FIGURE 4. TEST 1—TEMPERATURE VS TIME

(The individual curves are close together and somewhat difficult to differentiate; however, it shows that all the temperatures are close together.)

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ergy

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egF)

191 degF

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FIGURE 5. TEST 1—RELATIVE ENERGY RELEASE RATE VS TIME

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FIGURE 6. TEST 2

FIGURE 7. TEST 2 IN PROGRESS

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Time (min)

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(deg

F)



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egF)

621 degF

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6

HYPALON RB71 TESTS.

Two Hypalon RB71 assemblies were evaluated. One assembly was 1.5 inches thick and the other was 3/8 inches thick. The bay blankets and cap strips were fabricated with the same materials used in the baseline tests. In these tests, the ducts were wrapped with the Hypalon RB71 assembly and taped together at the bottom of the ducts with 6-inch-wide metallized Tedlar tape, as shown in figure 10. In the first test (test 3), with the 1.5-inch-thick Hypalon RB71 assembly, 4-inch spacers were used as opposed to the 8-inch spacers used in the first baseline test. This decreased the volume of test area. The test in progress is shown in figure 11. The temperature versus time graph is shown in figure 12, and the relative energy release rate versus time is shown in figure 13. A posttest photograph of the ducts is shown in figure 14. Two tests were conducted with the 3/8-inch-thick Hypalon RB71 assembly. In the first test (test 4), 8-inch spacers were used. Figure 15 depicts the test near completion. The temperature versus time graph is shown in figure 16, and the relative energy release rate versus time is shown in figure 17. A posttest view of the ducts is shown in figure 18. In the second test (test 5), 4-inch spacers were used. A pretest view of the ducts with the foam ignition block is shown in figure 19. The temperature versus time graph is shown in figure 20, and the relative energy release rate is shown in figure 21. A posttest photograph of the ducts is shown in figure 22. The distance from the top of the insulated ducts to the aluminum surface of the test article for tests 3, 4, and 5 is given in table 1.

FIGURE 10. TEST 3

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FIGURE 11. TEST 3 IN PROGRESS

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ativ

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egF)

530 degF

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FIGURE 14. TEST 3—POSTTEST PHOTOGRAPH OF DUCTS

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FIGURE 15. TEST 4—NEAR COMPLETION

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153 degF

10



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FIGURE 19. TEST 5

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182 degF

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13

TABLE 1. DISTANCE FROM TOP OF INSULATED DUCTS TO ALUMINUM SURFACE OF TEST ARTICLE

Test Distance (inches)

1 2 3 4 5 6 7 8

10.75 10.5 11.25 11.75 12 12 10 12

ADDITIONAL BASELINE TESTS OF METALLIZED TEDLAR FOR CONFIGURATION CONSISTENCY.

Three additional baseline tests were performed to configure the ducts with the tape on the bottom and the 4-inch spacers installed, as was done in two of the three Hypalon RB71 tests. The film cover material weight and the amount and density of fiberglass used in the first two tests differed from those used in the first set of baseline and Hypalon RB71 tests. In these first two tests, the bay blankets, cap strips, and ducts were fabricated with two layers of 0.34-pcf-density fiberglass and covered with metallized Tedlar film, weighing 1.25 oz/yd2. The material covering the ducts, however, was taped at the bottom with 6-inch-wide metallized Tedlar tape, as opposed to the first baseline tests where they were taped on top with 4-inch-wide tape. A pretest picture of the first test (test 6) is shown in figure 23. The temperature versus time graph is shown in figure 24, and the relative energy release rate versus time is shown in figure 25. A posttest picture of the ducts is shown in figure 26. In the second test (test 7), the ducts were positioned 2 inches closer to the ceiling of the test article. A pretest photograph is shown in figure 27. The temperature versus time graph is shown in figure 28, and the relative energy release rate versus time graph is shown in figure 29. In the third test (test 8), the bay blankets and cap strips were fabricated with the same materials used in the first baseline test and all of the Hypalon RB71 tests. The ducts were also wrapped with the same material used in the first baseline tests, but were taped together at the bottom with 6-inch-wide metallized Tedlar tape. The test in progress is shown in figure 30. The temperature versus time graph is shown in figure 31, and the relative energy release rate versus time graph is shown in figure 32. A posttest photograph of the ducts is shown in figure 33. The distance from the top of the insulated ducts to the aluminum surface of the test article for tests 6, 7, and 8 is given in table 1.

14

FIGURE 23. TEST 6

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240 degF

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FIGURE 26. MPV TEST 6—POSTTEST PHOTOGRAPH OF DUCTS

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FIGURE 27. TEST 7

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216 degF

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FIGURE 30. TEST 8—IN PROGRESS

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259 degF

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Documents

Results of Intermediate-Scale Flammability Tests Performed