Consultation expired with comments. The proposed Special Condition (SC) has been updated based on the comments received, and the corresponding Comment-Response Document (CRD) has been completed by EASA.
Details
The EASA response to comment #27 has been updated in the CRD at Issue 01-Rev-1 and the SC9 as well as the MOC to SC7 have been updated in the M-TS at Issue 02 to allow for more flexibility where to record the maximum dimensions allowed for a PED to be stowed inside the FCB.
Identification of issue
In recent years, EASA has made significant efforts to address the threat associated to thermal runaways of rechargeable and non-rechargeable lithium batteries that are certified as part of the aeroplane design.
Nonetheless, a significant amount of lithium batteries not included in the design configuration of the certified aeroplane, are brought on board by crew members, passengers, or as part of the cargo. Transportation of Portable Electronic Devices (PEDs) powered by lithium batteries on Large Aeroplanes is
addressed in the EASA Air Ops rules. PEDs that are commonly transported on Large Aeroplanes range from electronic flight bags (EFB) to devices carried by the crew or by passengers for personal convenience (mobile phones, tablets, laptop computers, e-cigarettes, etc.). An application to EASA for a major change has proposed the installation of a Fire Containment Bag (FCB) for the stowage of Portable Electronic Device (PED) carried by crew members on Large Aeroplanes. The FCB may be installed in various locations in the passenger cabin. The proposed stowage facilities are intended to minimize the hazard associated to thermal runaway of the lithium battery of the PED stowed inside the FCB.
Recent experience with lithium batteries, that are the main power supplies of PEDs, has shown that there is an increased fire risk associated to the use of such batteries. Lithium batteries are capable of ignition and subsequent explosion due to overheating. Overheating may be caused by shorting, rapid discharge or overcharging. Overheating results in thermal runaway, which is a chemical reaction within the battery causing the internal temperature and pressure to rise. The result is the release of flammable electrolyte from the battery and, in the case of disposable lithium batteries, the release of molten burning lithium. Once one battery cell goes into thermal runaway, it produces enough heat to cause adjacent battery cells to also go into thermal runaway. This produces a fire that repeatedly flares up as each battery cell in turn ruptures and releases its contents.
EASA considers that a lithium battery has a higher likelihood of catching fire through thermal runaway during or immediately following a charging cycle, although the effects of thermal runaway may be delayed. By removing external power from the device, it will be ensured that additional energy is not being fed to the battery to promote a fire. Charging of lithium batteries may lead to higher battery temperatures that can create the conditions for thermal runaway to occur.
To ensure that the installation of a FCB as PED stowage in an aeroplane cabin will minimize the hazards of crew carry-on PEDs stowage, the following Special Condition and its associated MOC are proposed to complement the applicable CS-25 Amendment 28.