AMC to Appendix F, Part IV - Test Method to Determine the Heat Release Rate from Cabin Materials Exposed to Radiant Heat

• ED Decision 2003/2/RM found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

AMC to Appendix F, Part IV – Test Method to Determine the Heat Release Rate from Cabin Materials Exposed to Radiant Heat ED Decision 2003/2/RM Appendix F, Part IV (b)(4) Air Distribution System. The air distribution is to be determined by the equipment design. The 3-to-1 ratio described in this paragraph is approximate. An external air distribution system which will deliver that ratio precisely is not permitted as a substitute for the air distributor plates. Appendix F, Part IV (b)(6) Specimen Holders. In order to accommodate specimens which distort and delaminate during testing, two 0·508 mm (0·020-inch) stainless steel wires should be used to secure the specimens to the holder during the testing. These wires should be used with all specimens and are in addition to the drip pan that should be used for materials which are prone to melting and dripping. Appendix F, Part IV (b)(8) Pilot-Flame Positions. Various installations have experienced difficulties with the pilot burners being extinguished during the test. The following revisions to the pilot burner configurations have been found to be acceptable: (1) For the lower pilot burner – a sparking device which either sparks automatically at approximately ½ to 1 second intervals or is manually operated, which requires continuous monitoring of the pilot flame. Note: This requires that the laboratory test procedure specifies that the technician must continuously monitor the pilot for each test and that failure to do so will invalidate the test results. (2) For the upper pilot burner – a manual or automatic sparking device or a revision to the hole system in the burner. One approved deviation utilises 14 holes using a number 59 drill bit. Appendix F, Part IV (c)(1) Heat Release Rate. The use of a flowmeter is not acceptable. The thermopile voltage should be measured for 10 seconds and then averaged. Appendix F, Part IV (e) Procedure. The outer door should be closed between tests to maintain the heat within the chamber. It is recommended that the outer door be hinged to facilitate implementing this recommendation. If a detachable door is used, a separate door should be installed during sample holder preparation and installation. This recommendation is based on the 40-seconds holding time (60 seconds less 20 seconds of data acquisition time) required in (e)(4), being insufficient to allow the chamber to reach equilibrium, if the outer door is open for too long between tests. Appendix F, Part IV (f) Calculations. It has been found that a typical range for the calibration factor is 8 to 15. If a calibration factor is calculated which falls outside this range, the calculation should be reviewed. If the factor continues to fall outside this range, the Agency should be contacted.