Cabin & Fire Safety Reports Search
|Title:||Review and Assessment of Transport Category Airplane Ditching Standards and Requirements|
|Author:||R.G.W. Cherry & Associates Limited|
Recent accident experience has raised questions as to whether the design and operational standards of large transport category airplanes, pertinent to water related accidents, might be improved to enhance occupant survival.
This study has been commissioned by Transport Canada and the UK Civil Aviation Authority (henceforth referred to as the Airworthiness Authorities) to carry out a detailed review of accident data and existing research applicable to water related accidents, to determine the need for changes to the relevant regulatory standards, taking into account the cost to industry and the likely benefits to occupant safety.
The study includes ditching and inadvertent water impact accidents involving western built airplanes certified for 20 or more passenger seats (and their cargo variants), that occurred over the period 1967 to 2009. In the context of this study, the term ditching includes planned and unplanned ditchings in which the flight crew knowingly makes a controlled emergency landing in water. Inadvertent water impact accidents are those that might occur during an overrun or undershoot, where the airplane alights on water. The study excludes non-survivable water impacts and accidents involving hijacked airplanes.
|Title:||Development of Next Generation Burner Characteristics for Fire Testing of Power Plant Materials and Components|
|Author:||Samir Tambe, Yi-Huan Kao, and San-Mou Jeng|
The Next Generation (NexGen) burner is a new burner designed by the Federal Aviation Administration (FAA) William J. Hughes Technical Center for the required FAA fire certification tests on power plant components. The objective of this study is to understand the performance of this burner and provide the benchmark to adapt the burner settings for future FAA fire tests. The NexGen burner was found to satisfy the temperature and heat flux requirements under the FAA fire test guidelines. This NexGen burner was modified by adding four tabs to the turbulator in the current study and was found to result in wider and more uniform flames, which increased the burner robustness for the fire test. Calibrations of heat flux and thermocouple (TC) temperature from the NexGen burner were much more sensitive to a change in the fuel flow rate than to a change in the air flow rate. However, the fire test results on the samples were also sensitive to air flow rate. It is recommended that both the fuel and the air flow rate of the NexGen burner be regulated in future FAA fire tests. The influence of TC size on flame calibrations and fire test results was studied. The burner calibrated with the smaller TC size produced less damage on the test sample. It is recommended that the FAA have a narrower tolerance on the TC size used in the temperature calibrations. The performance of the ISO propane burner was also studied. Heat flux produced by the ISO propane burner was found to be much lower than that produced by the NexGen burner, and the damage induced by the propane burner in a horizontal orientation was significantly less than that induced by the NexGen burner. Fire tests were conducted on two different sample sizes. Smaller samples could survive longer under the same burner operating conditions. It is recommended that the sample size be specified in future FAA fire tests.
This report discusses ongoing developmental efforts related to the Nexgen burner. It should be noted that the burner construction and settings discussed in this report are not representative of the most recent that are used on the Nexgen burner. For detailed construction drawings and to view other documentation and presentations that discuss the most up-to-date burner configurations, please see the FAA’s Fire Safety Branch’s website at www.fire.tc.faa.gov.
|Title:||Effect of Moisture on Ignition Time of Polymers|
|Author:||Natallia Safronava, Richard E. Lyon, Sean Crowley, Stanislav I. Stoliarov|
A previous study of polyetheretherketone showed that the ignitability of this high temperature engineering plastic is sensitive to the presence of absorbed moisture. The present research extends this work to include five other engineering plastics: polycarbonate, polyoxymethylene, polymethylmethacrylate, polyphenylsulfone, and polyhexamethyleneadipamide. Separate batches of each polymer were equilibrated in hot (80°C) water, 50% relative humidity at 20°C, or vacuum dried at 100°C and tested in a cone calorimeter at heat fluxes between 10–75 kW/m2. These hygrothermally conditioned samples were also examined by microscale combustion calorimetry to determine the effect of moisture on the decomposition and combustion properties. It was found that absorbed moisture did not change the thermal decomposition or ignition temperatures significantly, but was released as steam that formed microscopic surface bubbles at or above the softening (i.e., glass transition or melting) temperature of the polymer. The phase change from bound water to steam entrained in the polymer melt (i.e., foam) significantly reduced the ignition time as compared to dry samples. Attempts were made to account for the moisture-sensitive ignition delay in terms of thermal properties and chemical processes governing ignition and in a numerical thermokinetic pyrolysis model.