English Translation Version for Reference Only Number:CTSO-C174 Date of approval:Apr 17 2017 CAAC Approved by:Yang Zhenmei China Civil Aviation Technical Standard Order This China Civil Aviation Technical Standard Order (CTSO)is issued according to Part 37 of the China Civil Aviation Regulations (CCAR-37).Each CTSO is a criterion which the concerned aeronautical materials parts or appliances used on civil aircraft must ply with when it is presented for airworthiness certification. Battery Based Emergency Power Unit (BEPU) 1.Purpose. This China Civil Aviation Technical Standard Order (CTSO)is for manufacturers applying for battery based emergency power units (BEPU) CTSO authorization (CTSOA).This CTSO prescribes the minimum performance standards(MPS)that BEPU must first meet for approval and identification with the applicable CTSO marking. 2.Applicability. This CTSO affects new application submitted after its effective date. Major design changes to article approved under this CTSO will require a new authorization in accordance with section 21.310 of CCAR-21R3. 3.Requirements. New models of BEPUs identified and manufactured on or after the effective date of this CTSO must meet the requirements in this CTSO -1- English Translation Version for Reference Only CAAC CTSO-C174 including appendixes 1 2 and 3.The battery used in the BEPU must meet the requirements of CTSO-C173a Nickel-Cadmium and Lead Acid Batteries dated July 24 2014 or any other battery standards approved by the ...