693 1171. APPENDIX F, PART III, DID NOT EXIST PRIOR TO AMENDMENT 25-60.
1172. APPENDIX F, AMENDMENT 25-60, Effective June 16, 1986. This amendment added Part III.
PART III - TEST METHOD TO DETERMINE FLAME PENETRATION RESISTANCE OF CARGO COMPARTMENT LINERS.
(a) Criteria for Acceptance.
(1) At least three specimens of cargo compartment sidewall or ceiling liner panels must be tested.
(2) Each specimen tested must simulate the cargo compartment sidewall or ceiling liner panel, including any design features. such as joints, lamp assemblies, etc., the failure of which would affect the capability of the liner to safely contain a fire.
(3) There must be no flame penetration of any specimen within 5 minutes after application of the flame source and the peak temperature measured at 4-inches above the upper surface of the horizontal test sample must not exceed 400ºF.
(b) Summary of Method. This method provides a laboratory test procedure for measuring the capability of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2 Grade kerosene or equivalent burner fire source. Ceiling and sidewall liner panels may be tested individually provided a baffle is used to simulate the missing panel. Any specimen that passes the test as a ceiling liner panel may be used as a sidewall liner panel.
(c) Test Specimens.
(1) The specimen to be tested must measure 16±1/8-inches (406±3 mm) by 24±1/8-inches (610±3 mm).
(2) The specimens must be conditioned at 70±5ºF. (21±2ºC.) and 55±5% humidity for at least 24 hours before testing.
(d) Test Apparatus. The arrangement of the test apparatus, which is shown in Figure 3 of part II and Figures I through 3 of this part of Appendix F, must include the components described in this section. Minor details of the apparatus may vary, depending on the model of the burner used.
(1) Specimen Mounting Stand. The mounting stand for the test specimens consists of steel angles as shown in Figure 1.
(2) Test Burner. The burner to be used in testing must-
(i) Be a modified gun type.
(ii) Use a suitable nozzle and maintain fuel pressure to yield a 2 GPH fuel flow. For example: an 80 degree nozzle nominally rated at 2.25 GPH and operated at 85 pounds per square-inch (PSI) gage to deliver 2.03 GPH.
(iii) Have a 12-inch (305 mm) burner extension installed at the end of the draft tube with an opening 6-inches (152 mm) high and 11-inches (280 mm) wide as shown in Figure 3 of part II of this Appendix.
(iv) Have a burner fuel pressure regulator that is adjusted to deliver a nominal 2.0 GPH of #2 Grade kerosene or equivalent.
(v) Burner models which have been used successfully in testing are the Lenox Model OB- 32, Carlin Model 200 CRD and Park Model DPL. The basic burner is described in FAA Powerplant Engineering Report No. 3A, Standard Fire Test Apparatus and Procedure for Flexible Hose Assemblies, dated March 1978; however, the test settings specified in this Appendix differ in some instances from those specified in the report.
(3) Calorimeter.
(i) The calorimeter to be used in testing must be a total heat flux Foil Type Gardon Gage of an appropriate range (approximately 0 to 15.0 British thermal unit (BTU) per ft.2 sec., 0-17.0 watts/cm2). The calorimeter must be mounted in a 6 by 12-inch (152 by 305 mm) by 3/4-inch (19 mm) thick insulating block which is attached to a steel angle bracket for placement in the test stand during burner calibration as shown in Figure 2 of this part of this Appendix.
(ii) The insulating block must be monitored for deterioration and the mounting shimmed as necessary to ensure that the calorimeter face is parallel to the exit plane of the test burner cone.
(4) Thermocouples. The seven thermocouples to be used for testing must be 1/16-inch ceramic sheathed, type K, grounded thermocouples with a nominal 30 American wire gage (AWG) size conductor. The seven thermocouples must be attached to a steel angle bracket to form a thermocouple rake for placement in the test stand during burner calibration as shown in Figure 3 of this part of this Appendix.
(5) Apparatus Arrangement. The test burner must be mounted on a suitable stand to position the exit of the burner cone a distance of 8-inches from the ceiling liner panel and 2- inches from the sidewall liner panel. The burner stand should have the capability of allowing the burner to be swung away from the test specimen during warm-up periods.
(6) Instrumentation. A recording potentiometer or other suitable instrument with an appropriate range must be used to measure and record the outputs of the calorimeter and the thermocouples.
(7) Timing Device. A stopwatch or other device must be used to measure the time of flame application and the time of flame penetration, if it occurs.
(e) Preparation of Apparatus. Before calibration, all equipment must be turned on and allowed to stabilize, and the burner fuel flow must be adjusted as specified in paragraph (d)(2).
(f) Calibration. To ensure the proper thermal output of the burner the following test must be made:
(1) Remove the burner extension from the end of the draft tube. Turn on the blower portion of the burner without turning the fuel or igniters on. Measure the air velocity using a hot wire anemometer in the center of the draft tube across the face of the opening. Adjust the damper such that the air velocity is in the range of 1550 to 1800 ft./min. If tabs are being used at the exit of the draft tube, they must be removed prior to this measurement. Reinstall the draft tube extension cone.
(2) Place the calorimeter on the test stand as shown in Figure 2 at a distance of 8-inches (203 mm) from the exit of the burner cone to simulate the position of the horizontal test specimen.
(3) Turn on the burner, allow it to run for 2 minutes for warm-up, and adjust the damper to produce a calorimeter reading of 8.0±0.5 BTU per ft.2 sec. (9.1±0.6 Watts/cm2).
(4) Replace the calorimeter with the thermocouple rake (see Figure 3).
(5) Turn on the burner and ensure that each of the seven thermocouples reads 1700±100ºF.
(927± 38ºC.) to ensure steady state conditions have been achieved. If the temperature is out of this range, repeat steps 2 through 5 until proper readings are obtained.
(6) Turn off the burner and remove the thermocouple rake.
(7) Repeat (1) to ensure that the burner is in the correct range.
(g) Test Procedure.
(1) Mount a thermocouple of the same type as that used for calibration at a distance of 4- inches (102 mm) above the horizontal (ceiling) test specimen. The thermocouple should be centered over the burner cone.
(2) Mount the test specimen on the test stand shown in Figure 1 in either the horizontal or vertical position. Mount the insulating material in the other position.
(3) Position the burner so that flames will not impinge on the specimen, turn the burner on, and allow it to run for 2 minutes. Rotate the burner to apply the flame to the specimen and simultaneously start the timing device.
(4) Expose the test specimen to the flame for 5 minutes and then turn off the burner. The test may be terminated earlier if flame penetrations observed.
(5) When testing ceiling liner panels, record the peak temperature measured 4-inches above the sample.
(6) Record the time at which flame penetration occurs if applicable.
(h) Test Report. The test report must include the following:
(1) A complete description of the materials tested including type, manufacturer, thickness, and other appropriate data.
(2) Observations of the behavior of the test specimens during flame exposure such as delamination, resin ignition, smoke, etc., including the time of such occurrence.
(3) The time at which flame penetration occurs, if applicable, for each of the three specimens tested.
(4) Panel orientation (ceiling or sidewall).
HORIZONTIAL SPEC. POSION
HORIZONTIAL AND VERTICAL SPECIMENS ARE
CLAMPED IN PLACE ON ALL EDGES BETWEEN
ANGLES AS SHOWN IN VIEW A - A
TEST STAND FRAME - AL HORIZONTIAL SPEC VERTICAL SPEC. - SUPPORT ANGLE
TOP VIEW VIEW A - A (Typical) 16" VERTICAL SPEC. F POSITION
BURNER CONE
BURNER ASSE
BURNER SHIELD
SUPPORT BRACE 1"X 3" X 1/8" STEEL "U" CHANNEL
SIDE VIEW 697
C L 1" DIAMETER HOLE FOR
CALORIMETER MOUNTING
- 12 1/2"
MARINITE BLOCK 6" X 12" X 3/4" 6 1/4" 11" 25"
TOP VIEW NOTE: BRAKET IS CLAMPED TO TEST
STAND WITH CALORIMETER
CENTERED OVER BURNER CONE
WATER-COOLED
CALORIMETER 1" DIA 3/4" 8 + 1/8
STEEL ANGLE 1"X 1" X 1/8"
BURNER CONE
SIDE VIEW FIGURE 2. CALORIMETER BRACKET 698
SEVEN THERMOCOUPLE WIRES 24" 12 1/2" -
TOP VIEW
STEEL ANGLI X1 X 1/8
BURNER CONE
SIDE VIEW FIGURE 3. THERMOCOUPLE RAKE BRACKET 699
700 1173 – 1177. [RESERVED]
701 1178. APPENDIX F, PART IV, DID NOT EXIST PRIOR TO AMENDMENT 25-61.
1179. APPENDIX F, AMENDMENT 25-61, Effective August 20, 1986. This amendment added Part IV.
PART IV - TEST METHOD TO DETERMINE THE HEAT RELEASE RATE FROM CABIN MATERIALS EXPOSED TO RADIANT HEAT.
(a) Summary of Method. The specimen to be tested is injected into an environmental chamber through which a constant flow of air passes. The specimen's exposure is determined by a radiant heat source adjusted to produce the desired total heat flux on the specimen of
3.5 W/cm2 using a calibrated calorimeter. The specimen is tested so that the exposed surface is vertical. Combustion is initiated by piloted ignition. The combustion products leaving the chamber are monitored in order to calculate the release rate of heat.
(b) Apparatus. The Ohio State University (OSU) rate of heat release apparatus, as described below, is used. This is a modified version of the rate of heat release apparatus standardized by the American Society of Testing and Materials (ASTM), ASTM E-906.
(1) This apparatus is shown in Figure 1. All exterior surfaces of the apparatus, except the holding chamber, shall be insulated with 25 mm thick, low density, high temperature, fiberglass board insulation. A gasketed door through which the sample injection rod slides forms an airtight closure on the specimen hold chamber.
(2) Thermopile. The temperature difference between the air entering the environmental chamber and that leaving is monitored by a thermopile having three hot and three cold, 32 gauge Chromel-Alumel junctions. The hot Junctions are spaced across the top of the exhaust stack. Two hot junctions are located 25 mm from each side on diagonally opposite corners, and the third in the center of the chimney's cross-section 10 mm below the top of the chimney. The cold junctions are located in the pan below the lower air distribution plate (Refer to paragraph (b)(4)).
(i) Thermal Inertia Compensator. A compensator tab is made from 0.55 mm stainless steel sheet, 10 by 20 mm. An 800 mm length of 24 gauge Chromel-Alumel, glass insulated, duplex thermocouple wire is welded or silver soldered to the tab as shown in Figure 2, and the wire bent back so that it is flush against the metal surface.
(ii) The compensator tab must be mounted on the exhaust stack as shown in Figure 3 using a 6-32 round head machine screw, 12 mm long. Add small (approximately 4.5 mm O.D., 9 mm O.D.) washers between the head of the machine screw and the compensator tab to give the best response to a square wave input. (One or two washers should be adequate.) The "sharpness" of the square wave can be increased by changing the ratio of the output from the thermopile and compensator thermocouple which is fed to the recorder. The ratio is changed by adjusting the 1-K ohm variable resistor (R1) of the thermopile bleeder shown in Figure 4.
When adjusting compensation, keep R1 as small as possible. Adjustment of the compensator
702 must be made during calibration (Refer to paragraph (c)(1)) at a heat release rate of 7.0 plus or minus 0.5 kW.
(iii) Adjust the washers and the variable resistor (R1) so that 90 percent of full scale response is obtained in 8 to 10 seconds. There must be no overshoot, as shown in Figure 5A.
If an insufficient number of washers is added, or R1 is too small, the output with square wave input will look like Figure 5B; if too many washers are added and R1 is too large, the output will look like Figure 5A.
(iv) Subtract the output of the compensator from the thermopile. The junctions enclosed in the dotted circle of Figure 4 are kept at the same constant temperature by electrically insulating the junctions and placing them on the pipe carrying air to the manifold, then covering them and the pipe with thermal insulation.
(v) Thermopile hot junctions must be cleared of soot deposits on a daily basis during periods of testing.
(3) Radiation Source. A radiant heat source for generating a flux up to 100 kW/m2, using four silicon carbide elements, Type LL, 20-inches (50.8 cm) long by 5/8-inch (1.54 cm) O.D., nominal resistance 1.4 ohms, is shown in Figures 6A and 6B. The silicon carbide elements are mounted in the stainless steel panel box by inserting them through 15.9 mm holes in 0.8 mm thick ceramic fiber board. Location of the holes in the pads and stainless steel cover plates are shown in Figure 6B. The diamond shaped mask of 24 gauge stainless steel is added to provide uniform heat flux over the area occupied by the 150 by 150 mm vertical sample. A power supply of 12.5 kVA. adjustable from 0 to 270 volts, is required.
(4) Air Distribution System. The air entering the environmental chamber is distributed by a 6.3 mm thick aluminum plate having eight, No. 4 drill holes, 51 mm from sides on 102 mm centers, mounted at the base of the environmental chamber. A second plate of 18 gauge steel having 120, evenly spaced, No. 28 drill holes is mounted 150 mm above the aluminum plate. A well-regulated air supply is required. The air supply manifold at the base of the pyramidal section has 48, evenly spaced, No. 26 drill holes located 10 mm from the inner edge of the manifold so that 0.03 m3/second of air flows between the pyramidal sections and
0.01 m3/second flows through the environmental chamber when total air flow to apparatus is controlled at 0.04 m3/second.
(5) Exhaust Stack. An exhaust stack, 133 mm by 70 mm in cross section, and 254 mm long, fabricated from 28 gauge stainless steel, is mounted on the outlet of the pyramidal section. A 25 mm by 76 mm plate of 31 gauge stainless steel is centered inside the stack, perpendicular to the air flow, 75 mm above the base of the stack.
(6) Specimen Holders.
(i) The 150 mm by 150 mm specimen is tested in a vertical orientation. The holder (Figure 7) is provided with a specimen holder frame, which touches the specimen (which is wrapped with aluminum foil as required by paragraph (d)(3) of this part) along only the 10 mm
703 perimeter, and a "V" shaped spring to hold the assembly together. A detachable 12 mm x12 mm x150 mm drip pan is also provided for testing of materials prone to melting and dripping. The positioning of the spring and frame may be changed to accommodate different specimen thicknesses by inserting the retaining rod in different holes on the specimen holder.
(ii) Since the radiation shield described in ASTM E-906 is not used, a guide pin is added to the injection mechanism. This fits into a slotted metal plate on the injection mechanism outside of the holding chamber and can be used to provide accurate positioning of the specimen face after injection. The front surface of the specimen shall be 100 mm from the closed radiation doors after injection.
(iii) The specimen holder clips onto the mounted bracket (Figure 7). The mounting bracket is attached to the injection rod by three screws which pass through a wide area washer welded onto a 1/2-inch nut. The end of the injection rod is threaded to screw into the nut and a .020-inch thick wide area washer is held between two 1/2-inch nuts which are adjusted to tightly cover the hole in the radiation doors through which the injection rod or calibration calorimeter pass.
(7) Radiometers. A total-flux flush (calorimeter) mounted in the center of a 1/2-inch Kaowool "M" board inserted in the sample holder must be used to measure the total heat flux.
The total-flux calorimeter must have a view angle of 180 degrees and be calibrated for incident flux. The calorimeter calibration must be acceptable to the Administrator.
(8) Pilot-Flame Positions. Pilot ignition of the specimen must be accomplished by simultaneously exposing the specimen to a lower pilot burner and an upper pilot burner, as described in paragraph (b)(8)(i) and (b)(8)(ii), respectively.
(i) Lower Pilot Burner. The pilot-flame tubing must be 6.3 mm O.D., 0.8 mm wall stainless steel tubing. A mixture of 120 cm3/min. of methane and 850 cm3/min. of air must be fed to the lower pilot flame burner. The normal position of the end of the pilot burner tubing is 10 mm from, and perpendicular to, the exposed vertical surface of the specimen. The centerline at the outlet of the burner tubing must intersect the vertical centerline of the sample at a point 5 mm above the lower edge of the specimen.
(ii) Upper Pilot Burner. The pilot burner must be a straight length of 6.3 mm O.D.,
0.8 mm wall, stainless steel tubing that is 360 mm long. One end of the tubing shall be closed, and three No. 40 drill holes shall be drilled into the tubing, 60 mm apart, for gas ports, all radiating in the same direction. The first hole must be 5 mm from the closed end of the tubing.
The tube is inserted into the environmental chamber through a 6.6 mm hole drilled 10 mm above the upper edge of the window frame. The tube is supported and positioned by an adjustable "Z" shaped support mounted outside the environmental chamber, above the viewing window. The tube is positioned above and 20 mm behind the exposed upper edge of the specimen. The middle hole must be in the vertical plane perpendicular to the exposed surface of the specimen which passes through its vertical centerline and must be pointed toward the radiation source. The gas supplied to the burner must be methane adjusted to produce flame lengths of 25 mm.
(c) Calibration of Equipment.
(1) Heat Release Rate. A burner as shown in Figure 8 must be placed over the end of the lower pilot flame tubing using a gas-tight connection. The flow of gas to the pilot flame must be at least 99 percent methane and must be accurately metered. Prior to usage, the wet test meter is properly leveled and filled with distilled water to the tip of the internal pointer while no gas is flowing. Ambient temperature and pressure of the water are based on the internal wet test meter temperature. A baseline flow rate of approximately 1 liter/min is set and increased to higher preset flows of 2, 4, 6, and 8 liters/min. The rate is determined by using a stop watch to time a complete revolution of the wet test meter for both the baseline and higher flow, with the flow returned to base-line before changing to the next higher flow. The thermopile baseline voltage is measured. The gas flow to the burner must be increased to the higher preset flow and allowed to burn for 4.0 minutes, and the thermopile voltage must be measured. The sequence is repeated until all four values have been determined. The average of the four values must be used as the calibration factor. The procedure must be repeated if the percent relative standard deviation is greater than 5 percent. Calculations are shown in paragraph (f).
(2) Flux Uniformity. Uniformity of flux over the specimen must be checked periodically and after each heating element change to determine if it is within acceptable limits of ±5 percent
(d) Sample Preparation.
(1) The standard size for vertically mounted specimens is 150 mm x 150 mm for exposed surface with thickness up to 100 mm.
(2) Conditioning. Specimens must be conditioned as described in part I of this appendix.
(3) Mounting. Only one surface of a specimen will be exposed during a test. A single layer of 0.025 mm aluminum foil is wrapped tightly on all unexposed sides.
(e) Procedure.
(1) The power supply to the radiant panel is set to produce a radiant flux of 3.5 W/cm2.
The flux is measured at the point which the center of the specimen surface will occupy when positioned for test. The radiant flux is measured after the air flow through the equipment is adjusted to the desired rate. The sample should be tested in its end use thickness.
(2) The pilot flames are lighted and their position, as described in paragraph (b)(8), is checked.
(3) The air flow to the equipment is set at 0.04±0.001 m3/s at atmospheric pressure.
Proper air flow may be set and monitored by either: (1) An orifice meter designed to produce a pressure drop of at least 200 mm of the manometric fluid, or by; (2) A rotometer (variable