（Question on aircraft component, Cooling Unit.）
Is there a possibility to exempt “Supplemental Cooling Unit” (an aircraft component) containing a gas, UN 3159 1,1,1,2-Tetrafluoroethane? This aircraft component in question, a Supplemental Cooling Unit, contains 2.54 kg of the aforementioned gas and 5.67 kg of gas associated with UN 2857 Refrigerating machines. Gas pertaining to UN 2857 can be exempted from the regulation if the quantity is less than 12 kg according to SP A26, however, there is no reference in the rule about UN 3159 1,1,1,2-Tetrafluoroethane (2.54 kg). Can we regard this Supplemental Cooling Unit as UN 3159? Please advise. (31 May 16)
The Supplemental Cooling Unit in question should be declared as Div. 2.2 UN 3159 1,1,1,2-Tetrafluoroethane. The gas associated with UN 2857 is exempted by SP A26 and is “Not Restricted” and can be ignored.